This looks like a post-exploitation hardening measure: If an attacker is
able to redirect execution flow, they could use that to load a DSO which
contains additional code (or perhaps make the stack executable).
However, the checks are not in the correct place to be effective: If
they are performed before the critical operation, an attacker with
sufficient control over execution flow could simply jump directly to
the code which performs the operation, bypassing the check. The check
would have to be executed unconditionally after the operation and
terminate the process in case a caller violation was detected.
Furthermore, in _dl_check_caller, there was a fallback reading global
writable data (GL(dl_rtld_map).l_map_start and
GL(dl_rtld_map).l_text_end), which could conceivably be targeted by an
attacker to disable the check, too.
Other critical functions (such as system) remain completely
unprotected, so the value of these additional checks does not appear
that large. Therefore this commit removes this functionality.
Linux 4.15 adds NT_S390_RI_CB to linux/elf.h (and NT_ARM_SVE, which we
already have in glibc). This shows up that various other ELF note
values from linux/elf.h are missing from glibc's elf.h.
This patch adds the missing values that are relevant to glibc
architectures. As elf.h is a general description of the ELF format,
not necessarily limited to glibc configurations, there's an argument
for having the remaining NT_* values that Linux uses for non-glibc
architectures in glibc's elf.h as well, but this patch does not add
them.
Adding the NT_PRFPREG name is bug 14890. That bug also requests
making the NT_FPREGSET name obsolete. Given that elf.h is not just
for Linux but can describe ELF for other operating systems, I don't
think that a change of name in the Linux kernel is sufficient
justification for declaring the other name obsolete; there can be
multiple names for the same note value, even with incompatible
semantics, if those reflect variants of the ELF format in actual use.
For example, FreeBSD appears still to have the name NT_FPREGSET
<https://github.com/freebsd/freebsd/blob/master/sys/sys/elf_common.h>
(note: I haven't checked whether the FreeBSD kernel actually generates
such notes or whether this is actually an other-OS definition present
in FreeBSD's header).
[BZ #14890]
* elf/elf.h (NT_PRFPREG): New macro.
(NT_S390_VXRS_LOW): Likewise.
(NT_S390_VXRS_HIGH): Likewise.
(NT_S390_GS_CB): Likewise.
(NT_S390_GS_BC): Likewise.
(NT_S390_RI_CB): Likewise.
The only differences in ld.so are line numbers for asserts.
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
* elf/dl-addr.c (determine_info): Use ADDRIDX with DT_GNU_HASH.
* elf/dl-lookup.c (_dl_setup_hash): Likewise.
* elf/get-dynamic-info.h (elf_get_dynamic_info): Likewise.
The RISC-V port defines ELF flags that enforce compatibility between
various objects. This adds the shared support necessary for these
flags.
2018-01-25 Palmer Dabbelt <palmer@sifive.com>
* elf/cache.c (print_entry): Add FLAG_RISCV_FLOAT_ABI_SOFT and
FLAG_RISCV_FLOAT_ABI_DOUBLE.
* elf/elf.h (EF_RISCV_RVC): New define.
(EF_RISCV_FLOAT_ABI): Likewise.
(EF_RISCV_FLOAT_ABI_SOFT): Likewise.
(EF_RISCV_FLOAT_ABI_SINGLE): Likewise.
(EF_RISCV_FLOAT_ABI_DOUBLE): Likewise.
(EF_RISCV_FLOAT_ABI_QUAD): Likewise.
* sysdeps/generic/ldconfig.h (FLAG_RISCV_FLOAT_ABI_SOFT): New
define.
(FLAG_RISCV_FLOAT_ABI_DOUBLE): Likewise.
This patch synchronizes DF_1_* flags with binutils
and ensures that all DF_1_* flags defined in binutil's
include/elf/common.h are also defined glibc's elf/elf.h.
This is a user visible change since elf/elf.h is installed
by default as /usr/include/elf.h.
Signed-off-by: Carlos O'Donell <carlos@redhat.com>
This commit adds a new _dl_open_hook entry for dlvsym and implements the
function using the existing dl_lookup_symbol_x function supplied by the
dynamic loader.
A new hook variable, _dl_open_hook2, is introduced, which should make
this change suitable for backporting: For old statically linked
binaries, __libc_dlvsym will always return NULL.
The fillin_rpath function in elf/dl-load.c loops over each RPATH or
RUNPATH tokens and interprets empty tokens as the current directory
("./"). In practice the check for empty token is done *after* the
dynamic string token expansion. The expansion process can return an
empty string for the $ORIGIN token if __libc_enable_secure is set
or if the path of the binary can not be determined (/proc not mounted).
Fix that by moving the check for empty tokens before the dynamic string
token expansion. In addition, check for NULL pointer or empty strings
return by expand_dynamic_string_token.
The above changes highlighted a bug in decompose_rpath, an empty array
is represented by the first element being NULL at the fillin_rpath
level, but by using a -1 pointer in decompose_rpath and other functions.
Changelog:
[BZ #22625]
* elf/dl-load.c (fillin_rpath): Check for empty tokens before dynamic
string token expansion. Check for NULL pointer or empty string possibly
returned by expand_dynamic_string_token.
(decompose_rpath): Check for empty path after dynamic string
token expansion.
is_path argument is no longer used and could be safely removed.
* elf/dl-dst.h (DL_DST_COUNT): Remove is_path argument, all callers
updated.
* elf/dl-load.c (is_dst, _dl_dst_count, _dl_dst_substitute,
expand_dynamic_string_token): Likewise.
* sysdeps/generic/ldsodefs.h (_dl_dst_count, _dl_dst_substitute): Remove
is_path argument.
is_dst is called either by _dl_dst_count or by _dl_dst_substitute.
_dl_dst_count is called by DL_DST_COUNT only.
DL_DST_COUNT is called either by expand_dst with is_path == 0
or by expand_dynamic_string_token.
_dl_dst_substitute is called either from expand_dst with is_path == 0
or from expand_dynamic_string_token.
The latter function is called either from _dl_map_object with is_path == 0
or from fillin_rpath with is_path == 1 and name containing no ':'.
In any case (is_path && name[i] == ':') is always false and all code
depending on it can be safely removed.
* elf/dl-load.c (is_dst): Remove checks that is_path is set and name
contains ':', and all code depending on these checks.
There are just two users of _dl_dst_substitute: one is expand_dst that
sets is_path argument to 0, another one is expand_dynamic_string_token.
The latter function also has just two users: one is _dl_map_object that
sets is_path argument to 0, another one is fillin_rpath that sets
is_path argument to 1 and name argument contains no ':'.
In any case (is_path && name[i] == ':') is always false and all code
depending on it can be safely removed.
* elf/dl-load.c (_dl_dst_substitute): Remove checks that is_path
is set and name contains ':', and all code depending on these checks.
There are just two users of fillin_rpath: one is decompose_rpath that
sets check_trusted argument to 0, another one is _dl_init_paths that
sets check_trusted argument to __libc_enable_secure and invokes
fillin_rpath only when LD_LIBRARY_PATH is non-empty.
Starting with commit
glibc-2.25.90-512-gf6110a8fee2ca36f8e2d2abecf3cba9fa7b8ea7d,
LD_LIBRARY_PATH is ignored for __libc_enable_secure executables,
so check_trusted argument of fillin_rpath is always zero.
* elf/dl-load.c (is_trusted_path): Remove.
(fillin_rpath): Remove check_trusted argument and its use,
all callers changed.
After
commit 9d7a3741c9
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Fri Dec 15 16:59:33 2017 -0800
Add --enable-static-pie configure option to build static PIE [BZ #19574]
and
commit 00c714df39
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Mon Dec 18 12:24:26 2017 -0800
Pass -no-pie to GCC only if GCC defaults to PIE [BZ #22614]
$(no-pie-ldflag) is no longer effective since no-pie-ldflag is defined
to -no-pie only if GCC defaults to PIE. When --enable-static-pie is
used to configure glibc build and GCC doesn't default to PIE. no-pie-ldflag
is undefined and these tests:
elf/Makefile:LDFLAGS-tst-dlopen-aout = $(no-pie-ldflag)
elf/Makefile:LDFLAGS-tst-prelink = $(no-pie-ldflag)
elf/Makefile:LDFLAGS-tst-main1 = $(no-pie-ldflag)
gmon/Makefile:LDFLAGS-tst-gmon := $(no-pie-ldflag)
may fail to link. This patch replaces "-pie" with
$(if $($(@F)-no-pie),$(no-pie-ldflag),-pie)
and repleces
LDFLAGS-* = $(no-pie-ldflag)
with
tst-*-no-pie = yes
so that tst-dlopen-aout, tst-prelink, tst-main1 and tst-gmon are always
built as non-PIE, with and without --enable-static-pie, regardless if
GCC defaults to PIE or non-PIE.
Tested with build-many-glibcs.py without --enable-static-pie as well as
with --enable-static-pie for x86_64, x32 and i686.
[BZ #22630]
* Makeconfig (link-pie-before-libc): Replace -pie with
$(if $($(@F)-no-pie),$(no-pie-ldflag),-pie).
* elf/Makefile (LDFLAGS-tst-dlopen-aout): Removed.
(tst-dlopen-aout-no-pie): New.
(LDFLAGS-tst-prelink): Removed.
(tst-prelink-no-pie): New.
(LDFLAGS-tst-main1): Removed.
(tst-main1-no-pie): New.
* gmon/Makefile (LDFLAGS-tst-gmon): Removed.
(tst-gmon-no-pie): New.
GLRO (_rtld_global_ro) is read-only after initialization and can
therefore not be patched at run time, unlike the hook table addresses
and their contents, so this is a desirable hardening feature.
The hooks are only needed if ld.so has not been initialized, and this
happens only after static dlopen (dlmopen uses a single ld.so object
across all namespaces).
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Starting with commit
glibc-2.18.90-470-g2a939a7e6d81f109d49306bc2e10b4ac9ceed8f9 that
introduced substitution of dynamic string tokens in fillin_rpath,
_dl_init_paths invokes _dl_dst_substitute for $LD_LIBRARY_PATH twice:
the first time it's called directly, the second time the result
is passed on to fillin_rpath which calls expand_dynamic_string_token
which in turn calls _dl_dst_substitute, leading to the following
behaviour:
$ mkdir -p /tmp/'$ORIGIN' && cd /tmp/'$ORIGIN' &&
echo 'int main(){}' |gcc -xc - &&
strace -qq -E LD_LIBRARY_PATH='$ORIGIN' -e /open ./a.out
open("/tmp//tmp/$ORIGIN/tls/x86_64/libc.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/tmp//tmp/$ORIGIN/tls/libc.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/tmp//tmp/$ORIGIN/x86_64/libc.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/tmp//tmp/$ORIGIN/libc.so.6", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
open("/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
Fix this by removing the direct _dl_dst_substitute invocation.
* elf/dl-load.c (_dl_init_paths): Remove _dl_dst_substitute preparatory
code and invocation.
ldconfig supports `include' directives and use the glob function to
process them. The glob function sort entries according to the LC_COLLATE
category. When using a standard "include /etc/ld.so.conf.d/*.conf" entry
in /etc/ld.so.conf, the order therefore depends on the locale used to
run ldconfig. A few examples of locale specific order that might be
disturbing in that context compared to the C locale:
- The cs_CZ and sk_SK locales sort the digits after the letters.
- The et_EE locale sorts the 'z' between 's' and 't'.
This patch fixes that by setting LC_COLLATE to C in order to process
files in deterministic order, independently of the locale used to launch
ldconfig.
NOTE: This should NOT be backported to older release branches.
Changelog:
[BZ #22505]
* elf/ldconfig.c (main): Call setlocale to force LC_COLLATE to C.
The test tst-leaks1 exercises calling dlopen with a $ORIGIN DST.
This results in a theoretical leak e.g.
Memory not freed:
-----------------
Address Size Caller
0x0000000001d766c0 0x21 at 0x7fb1bd8bf4ab
Or as seen via valgrind:
==27582== 33 bytes in 1 blocks are still reachable in loss record 1 of 1
==27582== at 0x4C2CB6B: malloc (vg_replace_malloc.c:299)
==27582== by 0x40124AA: _dl_get_origin (dl-origin.c:50)
==27582== by 0x4007DB9: expand_dynamic_string_token (dl-load.c:382)
==27582== by 0x400899C: _dl_map_object (dl-load.c:2160)
==27582== by 0x4013020: dl_open_worker (dl-open.c:224)
==27582== by 0x5166F9B: _dl_catch_exception (dl-error-skeleton.c:198)
==27582== by 0x4012BD9: _dl_open (dl-open.c:594)
==27582== by 0x4E39EF5: dlopen_doit (dlopen.c:66)
==27582== by 0x5166F9B: _dl_catch_exception (dl-error-skeleton.c:198)
==27582== by 0x516700E: _dl_catch_error (dl-error-skeleton.c:217)
==27582== by 0x4E3A514: _dlerror_run (dlerror.c:162)
==27582== by 0x4E39F70: dlopen@@GLIBC_2.2.5 (dlopen.c:87)
There is no real leak.
The calling link map (the executable's link map) has it's l_origin
expanded for future use as part of _dl_get_origin, and that results
in the main executable link map having a N-byte allocation for
l->l_origin that is never freed since the executable's link map is
just a part of the process.
To take this into account we do one dlopen with $ORIGIN before
calling mtrace to force the initialization of the executable link
map.
Signed-off-by: Carlos O'Donell <carlos@redhat.com>
Static PIE extends address space layout randomization to static
executables. It provides additional security hardening benefits at
the cost of some memory and performance.
Dynamic linker, ld.so, is a standalone program which can be loaded at
any address. This patch adds a configure option, --enable-static-pie,
to embed the part of ld.so in static executable to create static position
independent executable (static PIE). A static PIE is similar to static
executable, but can be loaded at any address without help from a dynamic
linker. When --enable-static-pie is used to configure glibc, libc.a is
built as PIE and all static executables, including tests, are built as
static PIE. The resulting libc.a can be used together with GCC 8 or
above to build static PIE with the compiler option, -static-pie. But
GCC 8 isn't required to build glibc with --enable-static-pie. Only GCC
with PIE support is needed. When an older GCC is used to build glibc
with --enable-static-pie, proper input files are passed to linker to
create static executables as static PIE, together with "-z text" to
prevent dynamic relocations in read-only segments, which are not allowed
in static PIE.
The following changes are made for static PIE:
1. Add a new function, _dl_relocate_static_pie, to:
a. Get the run-time load address.
b. Read the dynamic section.
c. Perform dynamic relocations.
Dynamic linker also performs these steps. But static PIE doesn't load
any shared objects.
2. Call _dl_relocate_static_pie at entrance of LIBC_START_MAIN in
libc.a. crt1.o, which is used to create dynamic and non-PIE static
executables, is updated to include a dummy _dl_relocate_static_pie.
rcrt1.o is added to create static PIE, which will link in the real
_dl_relocate_static_pie. grcrt1.o is also added to create static PIE
with -pg. GCC 8 has been updated to support rcrt1.o and grcrt1.o for
static PIE.
Static PIE can work on all architectures which support PIE, provided:
1. Target must support accessing of local functions without dynamic
relocations, which is needed in start.S to call __libc_start_main with
function addresses of __libc_csu_init, __libc_csu_fini and main. All
functions in static PIE are local functions. If PIE start.S can't reach
main () defined in a shared object, the code sequence:
pass address of local_main to __libc_start_main
...
local_main:
tail call to main via PLT
can be used.
2. start.S is updated to check PIC instead SHARED for PIC code path and
avoid dynamic relocation, when PIC is defined and SHARED isn't defined,
to support static PIE.
3. All assembly codes are updated check PIC instead SHARED for PIC code
path to avoid dynamic relocations in read-only sections.
4. All assembly codes are updated check SHARED instead PIC for static
symbol name.
5. elf_machine_load_address in dl-machine.h are updated to support static
PIE.
6. __brk works without TLS nor dynamic relocations in read-only section
so that it can be used by __libc_setup_tls to initializes TLS in static
PIE.
NB: When glibc is built with GCC defaulted to PIE, libc.a is compiled
with -fPIE, regardless if --enable-static-pie is used to configure glibc.
When glibc is configured with --enable-static-pie, libc.a is compiled
with -fPIE, regardless whether GCC defaults to PIE or not. The same
libc.a can be used to build both static executable and static PIE.
There is no need for separate PIE copy of libc.a.
On x86-64, the normal static sln:
text data bss dec hex filename
625425 8284 5456 639165 9c0bd elf/sln
the static PIE sln:
text data bss dec hex filename
657626 20636 5392 683654 a6e86 elf/sln
The code size is increased by 5% and the binary size is increased by 7%.
Linker requirements to build glibc with --enable-static-pie:
1. Linker supports --no-dynamic-linker to remove PT_INTERP segment from
static PIE.
2. Linker can create working static PIE. The x86-64 linker needs the
fix for
https://sourceware.org/bugzilla/show_bug.cgi?id=21782
The i386 linker needs to be able to convert "movl main@GOT(%ebx), %eax"
to "leal main@GOTOFF(%ebx), %eax" if main is defined locally.
Binutils 2.29 or above are OK for i686 and x86-64. But linker status for
other targets need to be verified.
3. Linker should resolve undefined weak symbols to 0 in static PIE:
https://sourceware.org/bugzilla/show_bug.cgi?id=22269
4. Many ELF backend linkers incorrectly check bfd_link_pic for TLS
relocations, which should check bfd_link_executable instead:
https://sourceware.org/bugzilla/show_bug.cgi?id=22263
Tested on aarch64, i686 and x86-64.
Using GCC 7 and binutils master branch, build-many-glibcs.py with
--enable-static-pie with all patches for static PIE applied have the
following build successes:
PASS: glibcs-aarch64_be-linux-gnu build
PASS: glibcs-aarch64-linux-gnu build
PASS: glibcs-armeb-linux-gnueabi-be8 build
PASS: glibcs-armeb-linux-gnueabi build
PASS: glibcs-armeb-linux-gnueabihf-be8 build
PASS: glibcs-armeb-linux-gnueabihf build
PASS: glibcs-arm-linux-gnueabi build
PASS: glibcs-arm-linux-gnueabihf build
PASS: glibcs-arm-linux-gnueabihf-v7a build
PASS: glibcs-arm-linux-gnueabihf-v7a-disable-multi-arch build
PASS: glibcs-m68k-linux-gnu build
PASS: glibcs-microblazeel-linux-gnu build
PASS: glibcs-microblaze-linux-gnu build
PASS: glibcs-mips64el-linux-gnu-n32 build
PASS: glibcs-mips64el-linux-gnu-n32-nan2008 build
PASS: glibcs-mips64el-linux-gnu-n32-nan2008-soft build
PASS: glibcs-mips64el-linux-gnu-n32-soft build
PASS: glibcs-mips64el-linux-gnu-n64 build
PASS: glibcs-mips64el-linux-gnu-n64-nan2008 build
PASS: glibcs-mips64el-linux-gnu-n64-nan2008-soft build
PASS: glibcs-mips64el-linux-gnu-n64-soft build
PASS: glibcs-mips64-linux-gnu-n32 build
PASS: glibcs-mips64-linux-gnu-n32-nan2008 build
PASS: glibcs-mips64-linux-gnu-n32-nan2008-soft build
PASS: glibcs-mips64-linux-gnu-n32-soft build
PASS: glibcs-mips64-linux-gnu-n64 build
PASS: glibcs-mips64-linux-gnu-n64-nan2008 build
PASS: glibcs-mips64-linux-gnu-n64-nan2008-soft build
PASS: glibcs-mips64-linux-gnu-n64-soft build
PASS: glibcs-mipsel-linux-gnu build
PASS: glibcs-mipsel-linux-gnu-nan2008 build
PASS: glibcs-mipsel-linux-gnu-nan2008-soft build
PASS: glibcs-mipsel-linux-gnu-soft build
PASS: glibcs-mips-linux-gnu build
PASS: glibcs-mips-linux-gnu-nan2008 build
PASS: glibcs-mips-linux-gnu-nan2008-soft build
PASS: glibcs-mips-linux-gnu-soft build
PASS: glibcs-nios2-linux-gnu build
PASS: glibcs-powerpc64le-linux-gnu build
PASS: glibcs-powerpc64-linux-gnu build
PASS: glibcs-tilegxbe-linux-gnu-32 build
PASS: glibcs-tilegxbe-linux-gnu build
PASS: glibcs-tilegx-linux-gnu-32 build
PASS: glibcs-tilegx-linux-gnu build
PASS: glibcs-tilepro-linux-gnu build
and the following build failures:
FAIL: glibcs-alpha-linux-gnu build
elf/sln is failed to link due to:
assertion fail bfd/elf64-alpha.c:4125
This is caused by linker bug and/or non-PIC code in PIE libc.a.
FAIL: glibcs-hppa-linux-gnu build
elf/sln is failed to link due to:
collect2: fatal error: ld terminated with signal 11 [Segmentation fault]
https://sourceware.org/bugzilla/show_bug.cgi?id=22537
FAIL: glibcs-ia64-linux-gnu build
elf/sln is failed to link due to:
collect2: fatal error: ld terminated with signal 11 [Segmentation fault]
FAIL: glibcs-powerpc-linux-gnu build
FAIL: glibcs-powerpc-linux-gnu-soft build
FAIL: glibcs-powerpc-linux-gnuspe build
FAIL: glibcs-powerpc-linux-gnuspe-e500v1 build
elf/sln is failed to link due to:
ld: read-only segment has dynamic relocations.
This is caused by linker bug and/or non-PIC code in PIE libc.a. See:
https://sourceware.org/bugzilla/show_bug.cgi?id=22264
FAIL: glibcs-powerpc-linux-gnu-power4 build
elf/sln is failed to link due to:
findlocale.c:96:(.text+0x22c): @local call to ifunc memchr
This is caused by linker bug and/or non-PIC code in PIE libc.a.
FAIL: glibcs-s390-linux-gnu build
elf/sln is failed to link due to:
collect2: fatal error: ld terminated with signal 11 [Segmentation fault], core dumped
assertion fail bfd/elflink.c:14299
This is caused by linker bug and/or non-PIC code in PIE libc.a.
FAIL: glibcs-sh3eb-linux-gnu build
FAIL: glibcs-sh3-linux-gnu build
FAIL: glibcs-sh4eb-linux-gnu build
FAIL: glibcs-sh4eb-linux-gnu-soft build
FAIL: glibcs-sh4-linux-gnu build
FAIL: glibcs-sh4-linux-gnu-soft build
elf/sln is failed to link due to:
ld: read-only segment has dynamic relocations.
This is caused by linker bug and/or non-PIC code in PIE libc.a. See:
https://sourceware.org/bugzilla/show_bug.cgi?id=22263
Also TLS code sequence in SH assembly syscalls in glibc doesn't match TLS
code sequence expected by ld:
https://sourceware.org/bugzilla/show_bug.cgi?id=22270
FAIL: glibcs-sparc64-linux-gnu build
FAIL: glibcs-sparcv9-linux-gnu build
FAIL: glibcs-tilegxbe-linux-gnu build
FAIL: glibcs-tilegxbe-linux-gnu-32 build
FAIL: glibcs-tilegx-linux-gnu build
FAIL: glibcs-tilegx-linux-gnu-32 build
FAIL: glibcs-tilepro-linux-gnu build
elf/sln is failed to link due to:
ld: read-only segment has dynamic relocations.
This is caused by linker bug and/or non-PIC code in PIE libc.a. See:
https://sourceware.org/bugzilla/show_bug.cgi?id=22263
[BZ #19574]
* INSTALL: Regenerated.
* Makeconfig (real-static-start-installed-name): New.
(pic-default): Updated for --enable-static-pie.
(pie-default): New for --enable-static-pie.
(default-pie-ldflag): Likewise.
(+link-static-before-libc): Replace $(DEFAULT-LDFLAGS-$(@F))
with $(if $($(@F)-no-pie),$(no-pie-ldflag),$(default-pie-ldflag)).
Replace $(static-start-installed-name) with
$(real-static-start-installed-name).
(+prectorT): Updated for --enable-static-pie.
(+postctorT): Likewise.
(CFLAGS-.o): Add $(pie-default).
(CFLAGS-.op): Likewise.
* NEWS: Mention --enable-static-pie.
* config.h.in (ENABLE_STATIC_PIE): New.
* configure.ac (--enable-static-pie): New configure option.
(have-no-dynamic-linker): New LIBC_CONFIG_VAR.
(have-static-pie): Likewise.
Enable static PIE if linker supports --no-dynamic-linker.
(ENABLE_STATIC_PIE): New AC_DEFINE.
(enable-static-pie): New LIBC_CONFIG_VAR.
* configure: Regenerated.
* csu/Makefile (omit-deps): Add r$(start-installed-name) and
gr$(start-installed-name) for --enable-static-pie.
(extra-objs): Likewise.
(install-lib): Likewise.
(extra-objs): Add static-reloc.o and static-reloc.os
($(objpfx)$(start-installed-name)): Also depend on
$(objpfx)static-reloc.o.
($(objpfx)r$(start-installed-name)): New.
($(objpfx)g$(start-installed-name)): Also depend on
$(objpfx)static-reloc.os.
($(objpfx)gr$(start-installed-name)): New.
* csu/libc-start.c (LIBC_START_MAIN): Call _dl_relocate_static_pie
in libc.a.
* csu/libc-tls.c (__libc_setup_tls): Add main_map->l_addr to
initimage.
* csu/static-reloc.c: New file.
* elf/Makefile (routines): Add dl-reloc-static-pie.
(elide-routines.os): Likewise.
(DEFAULT-LDFLAGS-tst-tls1-static-non-pie): Removed.
(tst-tls1-static-non-pie-no-pie): New.
* elf/dl-reloc-static-pie.c: New file.
* elf/dl-support.c (_dl_get_dl_main_map): New function.
* elf/dynamic-link.h (ELF_DURING_STARTUP): Also check
STATIC_PIE_BOOTSTRAP.
* elf/get-dynamic-info.h (elf_get_dynamic_info): Likewise.
* gmon/Makefile (tests): Add tst-gmon-static-pie.
(tests-static): Likewise.
(DEFAULT-LDFLAGS-tst-gmon-static): Removed.
(tst-gmon-static-no-pie): New.
(CFLAGS-tst-gmon-static-pie.c): Likewise.
(CRT-tst-gmon-static-pie): Likewise.
(tst-gmon-static-pie-ENV): Likewise.
(tests-special): Likewise.
($(objpfx)tst-gmon-static-pie.out): Likewise.
(clean-tst-gmon-static-pie-data): Likewise.
($(objpfx)tst-gmon-static-pie-gprof.out): Likewise.
* gmon/tst-gmon-static-pie.c: New file.
* manual/install.texi: Document --enable-static-pie.
* sysdeps/generic/ldsodefs.h (_dl_relocate_static_pie): New.
(_dl_get_dl_main_map): Likewise.
* sysdeps/i386/configure.ac: Check if linker supports static PIE.
* sysdeps/x86_64/configure.ac: Likewise.
* sysdeps/i386/configure: Regenerated.
* sysdeps/x86_64/configure: Likewise.
* sysdeps/mips/Makefile (ASFLAGS-.o): Add $(pie-default).
(ASFLAGS-.op): Likewise.
SXID_ERASE is implicit for all environment variables. Avoid
mentioning it in the tunables list; that way only the ones with
SXID_IGNORE remain prominent and mentioned. TODO: we need to audit
each of those cases and drop them to SXID_ERASE wherever possible.
A glibc master build with --enable-nss-crypt using the NSS
crypto libraries fails during make check with the following error:
<command-line>:0:0: error: "USE_CRYPT" redefined [-Werror]
<command-line>:0:0: note: this is the location of the previous
definition
This is caused by commit 36975e8e7e
by H.J. Lu which replaces all = with +=. The fix is to undefine
USE_CRYPT before defining it to zero.
Committed as an obvious fix. Fixes the build issue on x86_64 with
no regressions.
Signed-off-by: Carlos O'Donell <carlos@redhat.com>
This patch adds several new tunables to control the behavior of
elision on supported platforms[1]. Since elision now depends
on tunables, we should always *compile* with elision enabled,
and leave the code disabled, but available for runtime
selection. This gives us *much* better compile-time testing of
the existing code to avoid bit-rot[2].
Tested on ppc, ppc64, ppc64le, s390x and x86_64.
[1] This part of the patch was initially proposed by
Paul Murphy but was "staled" because the framework have changed
since the patch was originally proposed:
https://patchwork.sourceware.org/patch/10342/
[2] This part of the patch was inititally proposed as a RFC by
Carlos O'Donnell. Make sense to me integrate this on the patch:
https://sourceware.org/ml/libc-alpha/2017-05/msg00335.html
* elf/dl-tunables.list: Add elision parameters.
* manual/tunables.texi: Add entries about elision tunable.
* sysdeps/unix/sysv/linux/powerpc/elision-conf.c:
Add callback functions to dynamically enable/disable elision.
Add multiple callbacks functions to set elision parameters.
Deleted __libc_enable_secure check.
* sysdeps/unix/sysv/linux/s390/elision-conf.c: Likewise.
* sysdeps/unix/sysv/linux/x86/elision-conf.c: Likewise.
* configure: Regenerated.
* configure.ac: Option enable_lock_elision was deleted.
* config.h.in: ENABLE_LOCK_ELISION flag was deleted.
* config.make.in: Remove references to enable_lock_elision.
* manual/install.texi: Elision configure option was removed.
* INSTALL: Regenerated to remove enable_lock_elision.
* nptl/Makefile:
Disable elision so it can verify error case for destroying a mutex.
* sysdeps/powerpc/nptl/elide.h:
Cleanup ENABLE_LOCK_ELISION check.
Deleted macros for the case when ENABLE_LOCK_ELISION was not defined.
* sysdeps/s390/configure: Regenerated.
* sysdeps/s390/configure.ac: Remove references to enable_lock_elision..
* nptl/tst-mutex8.c:
Deleted all #ifndef ENABLE_LOCK_ELISION from the test.
* sysdeps/powerpc/powerpc32/sysdep.h:
Deleted all ENABLE_LOCK_ELISION checks.
* sysdeps/powerpc/powerpc64/sysdep.h: Likewise.
* sysdeps/powerpc/sysdep.h: Likewise.
* sysdeps/s390/nptl/bits/pthreadtypes-arch.h: Likewise.
* sysdeps/unix/sysv/linux/powerpc/force-elision.h: Likewise.
* sysdeps/unix/sysv/linux/s390/elision-conf.h: Likewise.
* sysdeps/unix/sysv/linux/s390/force-elision.h: Likewise.
* sysdeps/unix/sysv/linux/s390/lowlevellock.h: Likewise.
* sysdeps/unix/sysv/linux/s390/Makefile: Remove references to
enable-lock-elision.
Reviewed-by: Tulio Magno Quites Machado Filho <tuliom@linux.vnet.ibm.com>
A note header has 3 4-bytes fields, followed by note name and note
descriptor. According to gABI, in a note entry, the note name field,
not note name size, is padded for the note descriptor. And the note
descriptor field, not note descriptor size, is padded for the next
note entry. Notes are aligned to 4 bytes in 32-bit objects and 8 bytes
in 64-bit objects.
For all GNU notes, the name is "GNU" which is 4 bytes. They have the
same format in the first 16 bytes in both 32-bit and 64-bit objects.
They differ by note descriptor size and note type. So far, .note.ABI-tag
and .note.gnu.build-id notes are always aligned to 4 bytes. The exsting
codes compute the note size by aligning the note name size and note
descriptor size to 4 bytes. It happens to produce the same value as
the actual note size by luck since the name size is 4 and offset of the
note descriptor is 16. But it will produce the wrong size when note
alignment is 8 bytes in 64-bit objects.
This patch defines ELF_NOTE_DESC_OFFSET and ELF_NOTE_NEXT_OFFSET to
properly compute offsets of note descriptor and next note. It uses
alignment of PT_NOTE segment to support both 4-byte and 8-byte note
alignments in 64-bit objects. To handle PT_NOTE segments with
incorrect alignment, which may lead to an infinite loop, if segment
alignment is less than 4, we treate alignment as 4 bytes since some
note segments have 0 or 1 byte alignment.
[BZ #22370]
* elf/dl-hwcaps.c (ROUND): Removed.
(_dl_important_hwcaps): Replace ROUND with ELF_NOTE_DESC_OFFSET
and ELF_NOTE_NEXT_OFFSET.
* elf/dl-load.c (ROUND): Removed.
(open_verify): Replace ROUND with ELF_NOTE_NEXT_OFFSET.
* elf/readelflib.c (ROUND): Removed.
(process_elf_file): Replace ROUND with ELF_NOTE_NEXT_OFFSET.
* include/elf.h [!_ISOMAC]: Include <libc-pointer-arith.h>.
[!_ISOMAC] (ELF_NOTE_DESC_OFFSET): New.
[!_ISOMAC] (ELF_NOTE_NEXT_OFFSET): Likewise.
Combine the four places where link maps are sorted into a single function.
This also moves the logic to skip the first map (representing the main
binary) to the callers.
To support Intel Control-flow Enforcement Technology (CET) run-time
control:
1. An architecture specific field in the writable ld.so namespace is
needed to indicate if CET features are enabled at run-time.
2. An architecture specific field in struct link_map is needed if
CET features are enabled in an ELF module.
This patch adds dl-procruntime.c to the writable ld.so namespace and
link_map.h to struct link_map.
Tested with build-many-glibcs.py.
* elf/dl-support.c: Include <dl-procruntime.c>.
* include/link.h: Include <link_map.h>.
* sysdeps/generic/dl-procruntime.c: New file.
* sysdeps/generic/link_map.h: Likewise.
* sysdeps/generic/ldsodefs.h: Include <dl-procruntime.c> in
the writable ld.so namespace.
These static functions are not needed if a target does not do lazy
tlsdesc initialization.
* elf/tlsdeschtab.h (_dl_tls_resolve_early_return_p): Mark unused.
(_dl_tlsdesc_wake_up_held_fixups): Likewise.
Use $(LDFLAGS-$(@F)) with tst-tls1-static-non-pie may not be sufficient
when static PIE is built by default. Use $(DEFAULT-LDFLAGS-$(@F)) in
+link-static-before-libc to make sure that tst-tls1-static-non-pie is
always built as non-PIE static executable and make sure that crt1.o is
used with tst-tls1-static-non-pie.
* Makeconfig (+link-static-before-libc): Use
$(DEFAULT-LDFLAGS-$(@F)).
* elf/Makefile (CRT-tst-tls1-static-non-pie): New.
(LDFLAGS-tst-tls1-static-non-pie): Renamed to ...
(DEFAULT-LDFLAGS-tst-tls1-static-non-pie): This.
Verify that crt1.o can be used with main () in a shared object.
* elf/Makefile (tests): Add tst-main1.
(modules-names): Add tst-main1mod.
($(objpfx)tst-main1): New.
(CRT-tst-main1): Likewise.
(LDFLAGS-tst-main1): Likewise.
(LDLIBS-tst-main1): Likewise.
(tst-main1mod.so-no-z-defs): Likewise.
* elf/tst-main1.c: New file.
* elf/tst-main1mod.c: Likewise.
(&_dl_main_map) is used instead of (&bootstrap_map) to bootstrap static
PIE. Define BOOTSTRAP_MAP with (&_dl_main_map) to avoid hardcode to
(&bootstrap_map).
* elf/rtld.c (BOOTSTRAP_MAP): New.
(RESOLVE_MAP): Replace (&bootstrap_map) with BOOTSTRAP_MAP.
* sysdeps/hppa/dl-machine.h (ELF_MACHINE_BEFORE_RTLD_RELOC):
Likewise.
* sysdeps/ia64/dl-machine.h (ELF_MACHINE_BEFORE_RTLD_RELOC):
Likewise.
* sysdeps/mips/dl-machine.h (ELF_MACHINE_BEFORE_RTLD_RELOC):
Likewise.
__dl_iterate_phdr is hidden and should be accessed directly within
libc.so and libc.a without using GOT nor PLT.
[BZ #18822]
* elf/dl-iteratephdr.c (hidden_proto (__dl_iterate_phdr)): Moved
to ...
* include/link.h (hidden_proto (__dl_iterate_phdr)): Here.
tst-tls1-static-non-pie is built with $(no-pie-ldflag) to make it a
non-PIE static executable, regardless if --enable-static-pie is used
to configure glibc.
* elf/Makefile (tests-static-internal): Add
tst-tls1-static-non-pie.
(LDFLAGS-tst-tls1-static-non-pie): New.
* elf/tst-tls1-static-non-pie.c: New file.
Current implementation of tunables does not set arena_max and arena_test
values. Any value provided by glibc.malloc.arena_max and
glibc.malloc.arena_test parameters is ignored.
These tunables have minval value set to 1 (see elf/dl-tunables.list file)
and undefined maxval value. In that case default value (which is 0. see
scripts/gen-tunables.awk) is being used to set maxval.
For instance, generated tunable_list[] entry for arena_max is:
(gdb) p *cur
$1 = {name = 0x7ffff7df6217 "glibc.malloc.arena_max",
type = {type_code = TUNABLE_TYPE_SIZE_T, min = 1, max = 0},
val = {numval = 0, strval = 0x0}, initialized = false,
security_level = TUNABLE_SECLEVEL_SXID_IGNORE,
env_alias = 0x7ffff7df622e "MALLOC_ARENA_MAX"}
As a result, any value of glibc.malloc.arena_max is ignored by
TUNABLE_SET_VAL_IF_VALID_RANGE macro
__type min = (__cur)->type.min; <- initialized to 1
__type max = (__cur)->type.max; <- initialized to 0!
if (min == max) <- false
{
min = __default_min;
max = __default_max;
}
if ((__type) (__val) >= min && (__type) (val) <= max) <- false
{
(__cur)->val.numval = val;
(__cur)->initialized = true;
}
Assigning correct min/max values at a build time fixes a problem.
Plus, a bit of optimization: Setting of default min/max values for the
given type at a run time might be eliminated.
* elf/dl-tunables.c (do_tunable_update_val): Range checking fix.
* scripts/gen-tunables.awk: Set unspecified minval and/or maxval
values to correct default value for given type.
ELF objects generated with "objcopy --only-keep-debug" have
Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
DYNAMIC 0x0+e28 0x0+200e40 0x0+200e40 0x0+ 0x0+1a0 RW 0x8
with 0 file size. ld.so should skip such PT_DYNAMIC segments.
Without a PT_DYNAMIC segment the loading of the shared object will
fail, and therefore ldd on such objects will also fail instead of
crashing. This provides better diagnostics for tooling that is
attempting to inspect the invalid shared objects which may just
contain debug information.
[BZ #22101]
* elf/Makefile (tests): Add tst-debug1.
($(objpfx)tst-debug1): New.
($(objpfx)tst-debug1.out): Likewise.
($(objpfx)tst-debug1mod1.so): Likewise.
* elf/dl-load.c (_dl_map_object_from_fd): Skip PT_DYNAMIC segment
with p_filesz == 0.
* elf/tst-debug1.c: New file.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Some programs have more than one source files. These non-lib modules
should not be compiled with -DMODULE_NAME=libc. This patch puts these
non-lib modules in $(others-extras) and adds $(others-extras) to
all-nonlib.
[BZ #21864]
* Makerules (all-nonlib): Add $(others-extras).
* catgets/Makefile (others-extras): New.
* elf/Makefile (others-extras): Likewise.
* nss/Makefile (others-extras): Likewise.
Since __libc_multiple_libcs is defined as hidden symbol in init-first.c,
it should be always marked with attribute_hidden.
[BZ #18822]
* csu/libc-start.c (__libc_multiple_libcs): Removed.
* elf/dl-open.c: Include <libc-internal.h>.
(__libc_multiple_libcs): Removed.
* elf/dl-sysdep.c: Include <libc-internal.h> instead of
<hp-timing.h>.
* include/libc-internal.h (__libc_multiple_libcs): New.
* misc/sbrk.c: Include <libc-internal.h>.
(__libc_multiple_libcs): Removed.
Assembler code passes the address of _dl_fini to __libc_start_main,
whose function pointer argument lacks the attribute. This means
that calls could use the wrong ABI. Fortunately, for zero-parameter
void-returning functions, internal_function does not change ABI
on i386 (the only architecture which uses internal_function), so
this inconsistency was harmless (which is why it had not been
noticed so far).
This commit separates allocating and raising exceptions. This
simplifies catching and re-raising them because it is no longer
necessary to make a temporary, on-stack copy of the exception message.
On Linux/i386, there are 3 ways to make a system call:
1. call *%gs:SYSINFO_OFFSET. This requires TLS initialization.
2. call *_dl_sysinfo. This requires relocation of _dl_sysinfo.
3. int $0x80. This is slower than #2 and #3, but works everywhere.
When an object file is compiled with PIC, #1 is prefered since it is
faster than #3 and doesn't require relocation of _dl_sysinfo. For
dynamic executables, ld.so initializes TLS. However, for static
executables, before TLS is initialized by __libc_setup_tls, #3 should
be used for system calls.
This patch adds <startup.h> which defines _startup_fatal and defaults
it to __libc_fatal. It replaces __libc_fatal with _startup_fatal in
static executables where it is called before __libc_setup_tls is called.
This header file is included in all files containing functions which are
called before __libc_setup_tls is called. On Linux/i386, when PIE is
enabled by default, _startup_fatal is turned into ABORT_INSTRUCTION and
I386_USE_SYSENTER is defined to 0 so that "int $0x80" is used for system
calls before __libc_setup_tls is called.
Tested on i686 and x86-64. Without this patch, all statically-linked
tests will fail on i686 when the compiler defaults to -fPIE.
[BZ #21913]
* csu/libc-tls.c: Include <startup.h> first.
(__libc_setup_tls): Call _startup_fatal instead of __libc_fatal.
* elf/dl-tunables.c: Include <startup.h> first.
* include/libc-symbols.h (BUILD_PIE_DEFAULT): New.
* sysdeps/generic/startup.h: New file.
* sysdeps/unix/sysv/linux/i386/startup.h: Likewise.
* sysdeps/unix/sysv/linux/i386/brk.c [BUILD_PIE_DEFAULT != 0]
(I386_USE_SYSENTER): New. Defined to 0.
tst-prelink.c checks for conflict with GLOB_DAT relocation against stdio.
On i386, there is no GLOB_DAT relocation against stdio with PIE. We
should compile tst-prelink.c without PIE.
[BZ #21815]
* elf/Makefile (CFLAGS-tst-prelink.c): New.
(LDFLAGS-tst-prelink): Likewise.
Gold doesn't support protected data symbol:
configure:5672: checking linker support for protected data symbol
configure:5682: gcc -fuse-ld=gold -nostdlib -nostartfiles -fno-stack-protector -fPIC -shared conftest.c -o conftest.so
configure:5685: $? = 0
configure:5692: gcc -fuse-ld=gold -nostdlib -nostartfiles -fno-stack-protector conftest.c -o conftest conftest.so
/usr/local/bin/ld.gold: error: /tmp/ccXWoofs.o: cannot make copy relocation for protected symbol 'bar', defined in conftest.so
collect2: error: ld returned 1 exit status
Run vismain only if linker supports protected data symbol.
* elf/Makefile (tests): Add vismain only if
$(have-protected-data) == yes.
(tests-pie): Likewise.
The function maybe_enable_malloc_check, which is called by
__tunables_init, calls __access_noerrno. It isn't problem when
symbol is is in ld.so, which has a special version of __access_noerrno
without stack protector. But when glibc is built with stack protector,
maybe_enable_malloc_check in libc.a can't call the regular version of
__access_noerrno with stack protector.
This patch changes how Linux defines the __access_noerrno to be an
inline call instead and thus preventing defining different build
rules for ld/static and shared.
H.J. Lu <hongjiu.lu@intel.com>
Adhemerval Zanella <adhemerval.zanella@linaro.org>
[BZ #21744]
* elf/dl-tunables.c: Include not-errno.h header.
* include/unistd.h (__access_noerrno): Remove definition.
* sysdeps/unix/sysv/linux/access.c (__access_noerrno): Likewise.
* sysdeps/generic/not-errno.h: New file.
* sysdeps/unix/sysv/linux/not-errno.h: Likewise.
The patch proposed by Peter Bergner [1] to libgcc in order to fix
[BZ #21707] adds a dependency on a symbol provided by the loader,
forcing the loader to be linked to tests after libgcc was linked.
It also requires to read the thread pointer during IRELA relocations.
Tested on powerpc, powerpc64, powerpc64le, s390x and x86_64.
[1] https://sourceware.org/ml/libc-alpha/2017-06/msg01383.html
[BZ #21707]
* csu/libc-start.c (LIBC_START_MAIN): Perform IREL{,A}
relocations before or after initializing the TCB on statically
linked executables. That's a per-architecture definition.
* elf/rtld.c (dl_main): Add a comment about thread-local
variables initialization.
* sysdeps/generic/libc-start.h: New file. Define
ARCH_APPLY_IREL and ARCH_SETUP_IREL.
* sysdeps/powerpc/Makefile:
[$(subdir) = elf && $(multi-arch) != no] (tests-static-internal): Add tst-tlsifunc-static.
[$(subdir) = elf && $(multi-arch) != no && $(build-shared) == yes]
(tests-internal): Add tst-tlsifunc.
* sysdeps/powerpc/tst-tlsifunc.c: New file.
* sysdeps/powerpc/tst-tlsifunc-static.c: Likewise.
* sysdeps/powerpc/powerpc64le/Makefile (f128-loader-link): New
variable.
[$(subdir) = math] (test-float128% test-ifloat128%): Force
linking to the loader after linking to libgcc.
[$(subdir) = wcsmbs || $(subdir) = stdlib] (bug-strtod bug-strtod2)
(bug-strtod2 tst-strtod-round tst-wcstod-round tst-strtod6 tst-strrom)
(tst-strfrom-locale strfrom-skeleton): Likewise.
* sysdeps/unix/sysv/linux/powerpc/libc-start.h: New file. Define
ARCH_APPLY_IREL and ARCH_SETUP_IREL.
Since _dl_resolve_conflicts is only used in elf/rtld.c, don't include
it in libc.a.
[BZ #21742]
* elf/Makefile (dl-routines): Move dl-conflict to ...
(rtld-routines): Here.
Add a new tunable (glibc.tune.cpu) to override CPU identification on
aarch64. This is useful in two cases: one where it is desirable to
pretend to be another CPU for purposes of testing or because routines
written for that CPU are beneficial for specific workloads and second
where the underlying kernel does not support emulation of MRS to get
the MIDR of the CPU.
* elf/dl-tunables.h (tunable_is_name): Move from...
* elf/dl-tunables.c (is_name): ... here.
(parse_tunables, __tunables_init): Adjust.
* manual/tunables.texi: Document glibc.tune.cpu.
* sysdeps/aarch64/dl-tunables.list: New file.
* sysdeps/unix/sysv/linux/aarch64/cpu-features.c (struct
cpu_list): New type.
(cpu_list): New list of CPU names and their MIDR.
(get_midr_from_mcpu): New function.
(init_cpu_features): Override MIDR if necessary.
Building the testsuite with current GCC mainline fails with:
loadtest.c: In function 'main':
loadtest.c:76:3: error: macro expands to multiple statements [-Werror=multistatement-macros]
for (map = MAPS; map != NULL; map = map->l_next) \
^
loadtest.c:165:2: note: in expansion of macro 'OUT'
OUT;
^~~
loadtest.c:164:7: note: some parts of macro expansion are not guarded by this 'if' clause
if (debug)
^~
This seems like a genuine bug, although fairly harmless; it means the
fflush call in the OUT macro is unconditional instead of being inside
the conditional as presumably intended. This patch makes this macro
use do { } while (0) to avoid the problem.
Tested for x86_64 (testsuite), and with build-many-glibcs.py for
aarch64-linux-gnu with GCC mainline.
* elf/loadtest.c (OUT): Define using do { } while (0).
Rename glibc.tune.ifunc to glibc.tune.hwcaps and move it to
sysdeps/x86/dl-tunables.list since it is x86 specicifc. Also
change type of data_cache_size, data_cache_size and
non_temporal_threshold to unsigned long int to match size_t.
Remove usage DEFAULT_STRLEN from cpu-tunables.c.
* elf/dl-tunables.list (glibc.tune.ifunc): Removed.
* sysdeps/x86/dl-tunables.list (glibc.tune.hwcaps): New.
Remove security_level on all fields.
* manual/tunables.texi: Replace ifunc with hwcaps.
* sysdeps/x86/cpu-features.c (TUNABLE_CALLBACK (set_ifunc)):
Renamed to ..
(TUNABLE_CALLBACK (set_hwcaps)): This.
(init_cpu_features): Updated.
* sysdeps/x86/cpu-features.h (cpu_features): Change type of
data_cache_size, data_cache_size and non_temporal_threshold to
unsigned long int.
* sysdeps/x86/cpu-tunables.c (DEFAULT_STRLEN): Removed.
(TUNABLE_CALLBACK (set_ifunc)): Renamed to ...
(TUNABLE_CALLBACK (set_hwcaps)): This. Update comments. Don't
use DEFAULT_STRLEN.
The current IFUNC selection is based on microbenchmarks in glibc. It
should give the best performance for most workloads. But other choices
may have better performance for a particular workload or on the hardware
which wasn't available at the selection was made. The environment
variable, GLIBC_TUNABLES=glibc.tune.ifunc=-xxx,yyy,-zzz...., can be used
to enable CPU/ARCH feature yyy, disable CPU/ARCH feature yyy and zzz,
where the feature name is case-sensitive and has to match the ones in
cpu-features.h. It can be used by glibc developers to override the
IFUNC selection to tune for a new processor or improve performance for
a particular workload. It isn't intended for normal end users.
NOTE: the IFUNC selection may change over time. Please check all
multiarch implementations when experimenting.
Also, GLIBC_TUNABLES=glibc.tune.x86_non_temporal_threshold=NUMBER is
provided to set threshold to use non temporal store to NUMBER,
GLIBC_TUNABLES=glibc.tune.x86_data_cache_size=NUMBER to set data cache
size, GLIBC_TUNABLES=glibc.tune.x86_shared_cache_size=NUMBER to set
shared cache size.
* elf/dl-tunables.list (tune): Add ifunc,
x86_non_temporal_threshold,
x86_data_cache_size and x86_shared_cache_size.
* manual/tunables.texi: Document glibc.tune.ifunc,
glibc.tune.x86_data_cache_size, glibc.tune.x86_shared_cache_size
and glibc.tune.x86_non_temporal_threshold.
* sysdeps/unix/sysv/linux/x86/dl-sysdep.c: New file.
* sysdeps/x86/cpu-tunables.c: Likewise.
* sysdeps/x86/cacheinfo.c
(init_cacheinfo): Check and get data cache size, shared cache
size and non temporal threshold from cpu_features.
* sysdeps/x86/cpu-features.c [HAVE_TUNABLES] (TUNABLE_NAMESPACE):
New.
[HAVE_TUNABLES] Include <unistd.h>.
[HAVE_TUNABLES] Include <elf/dl-tunables.h>.
[HAVE_TUNABLES] (TUNABLE_CALLBACK (set_ifunc)): Likewise.
[HAVE_TUNABLES] (init_cpu_features): Use TUNABLE_GET to set
IFUNC selection, data cache size, shared cache size and non
temporal threshold.
* sysdeps/x86/cpu-features.h (cpu_features): Add data_cache_size,
shared_cache_size and non_temporal_threshold.
LD_LIBRARY_PATH can only be used to reorder system search paths, which
is not useful functionality.
This makes an exploitable unbounded alloca in _dl_init_paths unreachable
for AT_SECURE=1 programs.
Since _dl_out_of_memory is static in elf/dl-error-skeleton.c:
static const char _dl_out_of_memory[] = "out of memory";
remove _dl_out_of_memory from elf/Versions.
* elf/Versions (ld): Remove _dl_out_of_memory.
ELFv2 functions with localentry:0 are those with a single entry point,
ie. global entry == local entry, that have no requirement on r2 or
r12 and guarantee r2 is unchanged on return. Such an external
function can be called via the PLT without saving r2 or restoring it
on return, avoiding a common load-hit-store for small functions.
This patch implements the ld.so changes necessary for this
optimization. ld.so needs to check that an optimized plt call
sequence is in fact calling a function implemented with localentry:0,
end emit a fatal error otherwise.
The elf/testobj6.c change is to stop "error while loading shared
libraries: expected localentry:0 `preload'" when running
elf/preloadtest, which we'd get otherwise.
* elf/elf.h (PPC64_OPT_LOCALENTRY): Define.
* sysdeps/alpha/dl-machine.h (elf_machine_fixup_plt): Add
refsym and sym parameters. Adjust callers.
* sysdeps/aarch64/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/arm/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/generic/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/hppa/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/i386/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/ia64/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/m68k/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/microblaze/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/mips/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/nios2/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/powerpc/powerpc32/dl-machine.h (elf_machine_fixup_plt):
Likewise.
* sysdeps/s390/s390-32/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/s390/s390-64/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/sh/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/sparc/sparc32/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/sparc/sparc64/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/tile/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/x86_64/dl-machine.h (elf_machine_fixup_plt): Likewise.
* sysdeps/powerpc/powerpc64/dl-machine.c (_dl_error_localentry): New.
(_dl_reloc_overflow): Increase buffser size. Formatting.
* sysdeps/powerpc/powerpc64/dl-machine.h (ppc64_local_entry_offset):
Delete reloc param, add refsym and sym. Check optimized plt
call stubs for localentry:0 functions. Adjust callers.
(elf_machine_fixup_plt, elf_machine_plt_conflict): Add refsym
and sym parameters. Adjust callers.
(_dl_reloc_overflow): Move attribute.
(_dl_error_localentry): Declare.
* elf/dl-runtime.c (_dl_fixup): Save original sym. Pass
refsym and sym to elf_machine_fixup_plt.
* elf/testobj6.c (preload): Call printf.
There are 2 minimal strtoul implementations in ld.so:
1. __strtoul_internal in elf/dl-minimal.c.
2. tunables_strtoul in elf/dl-tunables.c.
This patch adds _dl_strtoul to replace them. Tested builds with and
without --enable-tunables.
[BZ #21528]
* elf/dl-minimal.c (__strtoul_internal): Removed.
(strtoul): Likewise.
* elf/dl-misc.c (_dl_strtoul): New function.
* elf/dl-tunables.c (tunables_strtoul): Removed.
(tunable_initialize): Replace tunables_strtoul with _dl_strtoul.
* elf/rtld.c (process_envvars): Likewise.
* sysdeps/unix/sysv/linux/dl-librecon.h (_dl_osversion_init):
Likewise.
* sysdeps/generic/ldsodefs.h (_dl_strtoul): New prototype.
The LD_HWCAP_MASK environment variable was ignored in static binaries,
which is inconsistent with the behaviour of dynamically linked
binaries. This seems to have been because of the inability of
ld_hwcap_mask being read early enough to influence anything but now
that it is in tunables, the mask is usable in static binaries as well.
This feature is important for aarch64, which relies on HWCAP_CPUID
being masked out to disable multiarch. A sanity test on x86_64 shows
that there are no failures. Likewise for aarch64.
* elf/dl-hwcaps.h [HAVE_TUNABLES]: Always read hwcap_mask.
* sysdeps/sparc/sparc32/dl-machine.h [HAVE_TUNABLES]:
Likewise.
* sysdeps/x86/cpu-features.c (init_cpu_features): Always set
up hwcap and hwcap_mask.
Drop _dl_hwcap_mask when building with tunables. This completes the
transition of hwcap_mask reading from _dl_hwcap_mask to tunables.
* elf/dl-hwcaps.h: New file.
* elf/dl-hwcaps.c: Include it.
(_dl_important_hwcaps)[HAVE_TUNABLES]: Read and update
glibc.tune.hwcap_mask.
* elf/dl-cache.c: Include dl-hwcaps.h.
(_dl_load_cache_lookup)[HAVE_TUNABLES]: Read
glibc.tune.hwcap_mask.
* sysdeps/sparc/sparc32/dl-machine.h: Likewise.
* elf/dl-support.c (_dl_hwcap2)[HAVE_TUNABLES]: Drop
_dl_hwcap_mask.
* elf/rtld.c (rtld_global_ro)[HAVE_TUNABLES]: Drop
_dl_hwcap_mask.
(process_envvars)[HAVE_TUNABLES]: Likewise.
* sysdeps/generic/ldsodefs.h (rtld_global_ro)[HAVE_TUNABLES]:
Likewise.
* sysdeps/x86/cpu-features.c (init_cpu_features): Don't
initialize dl_hwcap_mask when tunables are enabled.
Add LD_HWCAP_MASK to tunables in preparation of it being removed from
rtld.c. This allows us to read LD_HWCAP_MASK much earlier so that it
can influence IFUNC resolution in aarch64.
This patch does not actually do anything other than read the
LD_HWCAP_MASK variable and add the tunables way to set the
LD_HWCAP_MASK, i.e. via the glibc.tune.hwcap_mask tunable. In a
follow-up patch, the _dl_hwcap_mask will be replaced with
glibc.tune.hwcap_mask to complete the transition.
* elf/dl-tunables.list: Add glibc.tune.hwcap_mask.
* scripts/gen-tunables.awk: Include dl-procinfo.h.
* manual/tunables.texi: Document glibc.tune.hwcap_mask.
The TUNABLE_SET_VALUE and family of macros (and my later attempt to
add a TUNABLE_GET) never quite went together very well because the
overall interface was not clearly defined. This patch is an attempt
to do just that.
This patch consolidates the API to two simple sets of macros,
TUNABLE_GET* and TUNABLE_SET*. If TUNABLE_NAMESPACE is defined,
TUNABLE_GET takes just the tunable name, type and a (optionally NULL)
callback function to get the value of the tunable. The callback
function, if non-NULL, is called if the tunable was externally set
(i.e. via GLIBC_TUNABLES or any future mechanism). For example:
val = TUNABLE_GET (check, int32_t, check_callback)
returns the value of the glibc.malloc.check tunable (assuming
TUNABLE_NAMESPACE is set to malloc) as an int32_t into VAL after
calling check_callback.
Likewise, TUNABLE_SET can be used to set the value of the tunable,
although this is currently possible only in the dynamic linker before
it relocates itself. For example:
TUNABLE_SET (check, int32_t, 2)
will set glibc.malloc.check to 2. Of course, this is not possible
since we set (or read) glibc.malloc.check long after it is relocated.
To access or set a tunable outside of TUNABLE_NAMESPACE, use the
TUNABLE_GET_FULL and TUNABLE_SET_FULL macros, which have the following
prototype:
TUNABLE_GET_FULL (glibc, tune, hwcap_mask, uint64_t, NULL)
TUNABLE_SET_FULL (glibc, tune, hwcap_mask, uint64_t, 0xffff)
In future the tunable list may get split into mutable and immutable
tunables where mutable tunables can be modified by the library and
userspace after relocation as well and TUNABLE_SET will be more useful
than it currently is. However whenever we actually do that split, we
will have to ensure that the mutable tunables are protected with
locks.
* elf/Versions (__tunable_set_val): Rename to __tunable_get_val.
* elf/dl-tunables.c: Likewise.
(do_tunable_update_val): New function.
(__tunable_set_val): New function.
(__tunable_get_val): Call CB only if the tunable was externally
initialized.
(tunables_strtoul): Replace strval with initialized.
* elf/dl-tunables.h (strval): Replace with a bool initialized.
(TUNABLE_ENUM_NAME, TUNABLE_ENUM_NAME1): Adjust names to
prevent collision.
(__tunable_set_val): New function.
(TUNABLE_GET, TUNABLE_GET_FULL): New macros.
(TUNABLE_SET, TUNABLE_SET_FULL): Likewise.
(TUNABLE_SET_VAL): Remove.
(TUNABLE_SET_VAL_WITH_CALLBACK): Likewise.
* README.tunables: Document the new macros.
* malloc/arena.c (ptmalloc_init): Adjust.
Since __tunables_init is internal to ld.so, we should mark it hidden
to avoid PLT. We should also avoid PLT when calling __tunable_set_val
within ld.so.
2017-05-25 Siddhesh Poyarekar <siddhesh@sourceware.org>
H.J. Lu <hongjiu.lu@intel.com>
* elf/dl-tunables.c (__tunable_set_val): Make a hidden alias.
* elf/dl-tunables.h (__tunables_init): Mark it hidden in rtld.
(__tunable_set_val): Likewise.
It was discovered that the dynamic linker allocates a massive amount
of memory that increases with the value of LD_HWCAP_MASK. Due to
this, setting its value to 0xffffffff in the environment of
tst-env-setuid would cause it to fail in some environments where
overcommit was disabled or severely constrained because malloc would
fail.
Since this test is only concerned with the value of LD_HWCAP_MASK
envvar being conserved (or not, for setxid binaries), lower its value
to avoid spurious failures.
The allocation bug is reported as #21502.
Recognize the uint64_t type in addition to the current int32_t and
size_t. This allows addition of tunables of uint64_t types. In
addition to adding the uint64_t type, this patch also consolidates
validation and reading of integer types in tunables.
One notable change is that of overflow computation in
tunables_strtoul. The function was lifted from __internal_strtoul,
but it does not need the boundary condition check (i.e. result ==
ULONG_MAX) since it does not need to set errno. As a result the check
can be simplified, which I have now done.
* elf/dl-tunable-types.h (tunable_type_code_t): New type
TUNABLE_TYPE_UINT_64.
* elf/dl-tunables.c (tunables_strtoul): Return uint64_t.
Simplify computation of overflow.
(tunable_set_val_if_valid_range_signed,
tunable_set_val_if_valid_range_unsigned): Remove and replace
with this...
(TUNABLE_SET_VAL_IF_VALID_RANGE): ... New macro.
(tunable_initialize): Adjust. Add uint64_t support.
(__tunable_set_val): Add uint64_t support.
* README.tunables: Document it.
This patch adds a new build module called 'testsuite'.
IS_IN (testsuite) implies _ISOMAC, as do IS_IN_build and __cplusplus
(which means several ad-hoc tests for __cplusplus can go away).
libc-symbols.h now suppresses almost all of *itself* when _ISOMAC is
defined; in particular, _ISOMAC mode does not get config.h
automatically anymore.
There are still quite a few tests that need to see internal gunk of
one variety or another. For them, we now have 'tests-internal' and
'test-internal-extras'; files in this category will still be compiled
with MODULE_NAME=nonlib, and everything proceeds as it always has.
The bulk of this patch is moving tests from 'tests' to
'tests-internal'. There is also 'tests-static-internal', which has
the same effect on files in 'tests-static', and 'modules-names-tests',
which has the *inverse* effect on files in 'modules-names' (it's
inverted because most of the things in modules-names are *not* tests).
For both of these, the file must appear in *both* the new variable and
the old one.
There is also now a special case for when libc-symbols.h is included
without MODULE_NAME being defined at all. (This happens during the
creation of libc-modules.h, and also when preprocessing Versions
files.) When this happens, IS_IN is set to be always false and
_ISOMAC is *not* defined, which was the status quo, but now it's
explicit.
The remaining changes to C source files in this patch seemed likely to
cause problems in the absence of the main change. They should be
relatively self-explanatory. In a few cases I duplicated a definition
from an internal header rather than move the test to tests-internal;
this was a judgement call each time and I'm happy to change those
however reviewers feel is more appropriate.
* Makerules: New subdir configuration variables 'tests-internal'
and 'test-internal-extras'. Test files in these categories will
still be compiled with MODULE_NAME=nonlib. Test files in the
existing categories (tests, xtests, test-srcs, test-extras) are
now compiled with MODULE_NAME=testsuite.
New subdir configuration variable 'modules-names-tests'. Files
which are in both 'modules-names' and 'modules-names-tests' will
be compiled with MODULE_NAME=testsuite instead of
MODULE_NAME=extramodules.
(gen-as-const-headers): Move to tests-internal.
(do-tests-clean, common-mostlyclean): Support tests-internal.
* Makeconfig (built-modules): Add testsuite.
* Makefile: Change libof-check-installed-headers-c and
libof-check-installed-headers-cxx to 'testsuite'.
* Rules: Likewise. Support tests-internal.
* benchtests/strcoll-inputs/filelist#en_US.UTF-8:
Remove extra-modules.mk.
* config.h.in: Don't check for __OPTIMIZE__ or __FAST_MATH__ here.
* include/libc-symbols.h: Move definitions of _GNU_SOURCE,
PASTE_NAME, PASTE_NAME1, IN_MODULE, IS_IN, and IS_IN_LIB to the
very top of the file and rationalize their order.
If MODULE_NAME is not defined at all, define IS_IN to always be
false, and don't define _ISOMAC.
If any of IS_IN (testsuite), IS_IN_build, or __cplusplus are
true, define _ISOMAC and suppress everything else in this file,
starting with the inclusion of config.h.
Do check for inappropriate definitions of __OPTIMIZE__ and
__FAST_MATH__ here, but only if _ISOMAC is not defined.
Correct some out-of-date commentary.
* include/math.h: If _ISOMAC is defined, undefine NO_LONG_DOUBLE
and _Mlong_double_ before including math.h.
* include/string.h: If _ISOMAC is defined, don't expose
_STRING_ARCH_unaligned. Move a comment to a more appropriate
location.
* include/errno.h, include/stdio.h, include/stdlib.h, include/string.h
* include/time.h, include/unistd.h, include/wchar.h: No need to
check __cplusplus nor use __BEGIN_DECLS/__END_DECLS.
* misc/sys/cdefs.h (__NTHNL): New macro.
* sysdeps/m68k/m680x0/fpu/bits/mathinline.h
(__m81_defun): Use __NTHNL to avoid errors with GCC 6.
* elf/tst-env-setuid-tunables.c: Include config.h with _LIBC
defined, for HAVE_TUNABLES.
* inet/tst-checks-posix.c: No need to define _ISOMAC.
* intl/tst-gettext2.c: Provide own definition of N_.
* math/test-signgam-finite-c99.c: No need to define _ISOMAC.
* math/test-signgam-main.c: No need to define _ISOMAC.
* stdlib/tst-strtod.c: Convert to test-driver. Split locale_test to...
* stdlib/tst-strtod1i.c: ...this new file.
* stdlib/tst-strtod5.c: Convert to test-driver and add copyright notice.
Split tests of __strtod_internal to...
* stdlib/tst-strtod5i.c: ...this new file.
* string/test-string.h: Include stdint.h. Duplicate definition of
inhibit_loop_to_libcall here (from libc-symbols.h).
* string/test-strstr.c: Provide dummy definition of
libc_hidden_builtin_def when including strstr.c.
* sysdeps/ia64/fpu/libm-symbols.h: Suppress entire file in _ISOMAC
mode; no need to test __STRICT_ANSI__ nor __cplusplus as well.
* sysdeps/x86_64/fpu/math-tests-arch.h: Include cpu-features.h.
Don't include init-arch.h.
* sysdeps/x86_64/multiarch/test-multiarch.h: Include cpu-features.h.
Don't include init-arch.h.
* elf/Makefile: Move tst-ptrguard1-static, tst-stackguard1-static,
tst-tls1-static, tst-tls2-static, tst-tls3-static, loadtest,
unload, unload2, circleload1, neededtest, neededtest2,
neededtest3, neededtest4, tst-tls1, tst-tls2, tst-tls3,
tst-tls6, tst-tls7, tst-tls8, tst-dlmopen2, tst-ptrguard1,
tst-stackguard1, tst-_dl_addr_inside_object, and all of the
ifunc tests to tests-internal.
Don't add $(modules-names) to test-extras.
* inet/Makefile: Move tst-inet6_scopeid_pton to tests-internal.
Add tst-deadline to tests-static-internal.
* malloc/Makefile: Move tst-mallocstate and tst-scratch_buffer to
tests-internal.
* misc/Makefile: Move tst-atomic and tst-atomic-long to tests-internal.
* nptl/Makefile: Move tst-typesizes, tst-rwlock19, tst-sem11,
tst-sem12, tst-sem13, tst-barrier5, tst-signal7, tst-tls3,
tst-tls3-malloc, tst-tls5, tst-stackguard1, tst-sem11-static,
tst-sem12-static, and tst-stackguard1-static to tests-internal.
Link tests-internal with libpthread also.
Don't add $(modules-names) to test-extras.
* nss/Makefile: Move tst-field to tests-internal.
* posix/Makefile: Move bug-regex5, bug-regex20, bug-regex33,
tst-rfc3484, tst-rfc3484-2, and tst-rfc3484-3 to tests-internal.
* stdlib/Makefile: Move tst-strtod1i, tst-strtod3, tst-strtod4,
tst-strtod5i, tst-tls-atexit, and tst-tls-atexit-nodelete to
tests-internal.
* sunrpc/Makefile: Move tst-svc_register to tests-internal.
* sysdeps/powerpc/Makefile: Move test-get_hwcap and
test-get_hwcap-static to tests-internal.
* sysdeps/unix/sysv/linux/Makefile: Move tst-setgetname to
tests-internal.
* sysdeps/x86_64/fpu/Makefile: Add all libmvec test modules to
modules-names-tests.
cppflags-iterator.mk no longer has anything to do with CPPFLAGS; all
it does is set libof-$(foo) for a list of files. extra-modules.mk
does the same thing, but with a different input variable, and doesn't
let the caller control the module. Therefore, this patch gives
cppflags-iterator.mk a better name, removes extra-modules.mk, and
updates all uses of both.
* extra-modules.mk: Delete file.
* cppflags-iterator.mk: Rename to ...
* libof-iterator.mk: ...this. Adjust comments.
* Makerules, extra-lib.mk, benchtests/Makefile, elf/Makefile
* elf/rtld-Rules, iconv/Makefile, locale/Makefile, malloc/Makefile
* nscd/Makefile, sunrpc/Makefile, sysdeps/s390/Makefile:
Use libof-iterator.mk instead of cppflags-iterator.mk or
extra-modules.mk.
* benchtests/strcoll-inputs/filelist#en_US.UTF-8: Remove
extra-modules.mk and cppflags-iterator.mk, add libof-iterator.mk.
Add support to getauxval() for new types to get L1, L2, L3 cache sizes,
cache line sizes, and cache associativities. The new types for
getauxval() were added in the stream for Linux kernel v4.11 in commit
98a5f361b8625c6f4841d6ba013bbf0e80d08147.
* elf/elf.h (AT_L1I_CACHESIZE, AT_L1I_CACHEGEOMETRY, AT_L1D_CACHESIZE,
AT_L1D_CACHEGEOMETRY, AT_L2_CACHESIZE, AT_L2_CACHEGEOMETRY,
AT_L3_CACHESIZE, AT_L3_CACHEGEOMETRY): New. Add auxvec
identifiers from kernel arch/powerpc/include/uapi/asm/auxvec.h.
Since commit 8b9e9c3c0b, security_level replaces
is_secure. There were some old files need to be updated.
2017-03-23 Sunyeop Lee <sunyeop97@gmail.com>
* README.tunables: Updated descriptions.
* elf/dl-tunables.list: Fixed typo: SXID_NONE -> NONE.
* scripts/gen-tunables.awk: Updated the code related to the commit.
calls with constant strings shows a small (~10%) performance gain, strdup is
typically used in error reporting code, so not performance critical.
Remove the now unused __need_malloc_and_calloc related defines from stdlib.h.
Rename existing uses of str(n)dup to __str(n)dup so it no longer needs to be
redirected to a builtin. Also building GLIBC with -Os now no longer shows
localplt or linkname space failures (partial fix for BZ #15105 and BZ #19463).
[BZ #15105]
[BZ #19463]
* elf/dl-cache.c (_dl_load_cache_lookup): Use __strdup.
* inet/rcmd.c (rcmd_af): Likewise.
* inet/rexec.c (rexec_af): Likewise.
* intl/dcigettext.c (_LIBC): Likewise.
* intl/finddomain.c (_nl_find_domain): Use strdup expansion.
* locale/loadarchive.c (_nl_load_locale_from_archive): Use __strdup.
* locale/setlocale.c (setlocale): Likewise.
* posix/spawn_faction_addopen.c
(posix_spawn_file_actions_addopen): Likewise.
* stdlib/putenv.c (putenv): Use __strndup.
* sunrpc/svc_simple.c (__registerrpc): Use __strdup.
* sysdeps/posix/getaddrinfo.c (gaih_inet): Use __strdup/__strndup.
* include/stdlib.h (__need_malloc_and_calloc): Remove uses.
(__Need_M_And_C) Remove define/undef.
* stdlib/stdlib.h (__need_malloc_and_calloc): Remove uses.
(__malloc_and_calloc_defined): Remove define.
* string/bits/string2.h (__strdup): Remove define.
(strdup): Likewise.
(__strndup): Likewise.
(strndup): Likewise.
The LD_HWCAP_MASK environment variable may alter the selection of
function variants for some architectures. For AT_SECURE process it
means that if an outdated routine has a bug that would otherwise not
affect newer platforms by default, LD_HWCAP_MASK will allow that bug
to be exploited.
To be on the safe side, ignore and disable LD_HWCAP_MASK for setuid
binaries.
[BZ #21209]
* elf/rtld.c (process_envvars): Ignore LD_HWCAP_MASK for
AT_SECURE processes.
* sysdeps/generic/unsecvars.h: Add LD_HWCAP_MASK.
* elf/tst-env-setuid.c (test_parent): Test LD_HWCAP_MASK.
(test_child): Likewise.
* elf/Makefile (tst-env-setuid-ENV): Add LD_HWCAP_MASK.
posix/wordexp-test.c used libc-internal.h for PTR_ALIGN_DOWN; similar
to what was done with libc-diag.h, I have split the definitions of
cast_to_integer, ALIGN_UP, ALIGN_DOWN, PTR_ALIGN_UP, and PTR_ALIGN_DOWN
to a new header, libc-pointer-arith.h.
It then occurred to me that the remaining declarations in libc-internal.h
are mostly to do with early initialization, and probably most of the
files including it, even in the core code, don't need it anymore. Indeed,
only 19 files actually need what remains of libc-internal.h. 23 others
need libc-diag.h instead, and 12 need libc-pointer-arith.h instead.
No file needs more than one of them, and 16 don't need any of them!
So, with this patch, libc-internal.h stops including libc-diag.h as
well as losing the pointer arithmetic macros, and all including files
are adjusted.
* include/libc-pointer-arith.h: New file. Define
cast_to_integer, ALIGN_UP, ALIGN_DOWN, PTR_ALIGN_UP, and
PTR_ALIGN_DOWN here.
* include/libc-internal.h: Definitions of above macros
moved from here. Don't include libc-diag.h anymore either.
* posix/wordexp-test.c: Include stdint.h and libc-pointer-arith.h.
Don't include libc-internal.h.
* debug/pcprofile.c, elf/dl-tunables.c, elf/soinit.c, io/openat.c
* io/openat64.c, misc/ptrace.c, nptl/pthread_clock_gettime.c
* nptl/pthread_clock_settime.c, nptl/pthread_cond_common.c
* string/strcoll_l.c, sysdeps/nacl/brk.c
* sysdeps/unix/clock_settime.c
* sysdeps/unix/sysv/linux/i386/get_clockfreq.c
* sysdeps/unix/sysv/linux/ia64/get_clockfreq.c
* sysdeps/unix/sysv/linux/powerpc/get_clockfreq.c
* sysdeps/unix/sysv/linux/sparc/sparc64/get_clockfreq.c:
Don't include libc-internal.h.
* elf/get-dynamic-info.h, iconv/loop.c
* iconvdata/iso-2022-cn-ext.c, locale/weight.h, locale/weightwc.h
* misc/reboot.c, nis/nis_table.c, nptl_db/thread_dbP.h
* nscd/connections.c, resolv/res_send.c, soft-fp/fmadf4.c
* soft-fp/fmasf4.c, soft-fp/fmatf4.c, stdio-common/vfscanf.c
* sysdeps/ieee754/dbl-64/e_lgamma_r.c
* sysdeps/ieee754/dbl-64/k_rem_pio2.c
* sysdeps/ieee754/flt-32/e_lgammaf_r.c
* sysdeps/ieee754/flt-32/k_rem_pio2f.c
* sysdeps/ieee754/ldbl-128/k_tanl.c
* sysdeps/ieee754/ldbl-128ibm/k_tanl.c
* sysdeps/ieee754/ldbl-96/e_lgammal_r.c
* sysdeps/ieee754/ldbl-96/k_tanl.c, sysdeps/nptl/futex-internal.h:
Include libc-diag.h instead of libc-internal.h.
* elf/dl-load.c, elf/dl-reloc.c, locale/programs/locarchive.c
* nptl/nptl-init.c, string/strcspn.c, string/strspn.c
* malloc/malloc.c, sysdeps/i386/nptl/tls.h
* sysdeps/nacl/dl-map-segments.h, sysdeps/x86_64/atomic-machine.h
* sysdeps/unix/sysv/linux/spawni.c
* sysdeps/x86_64/nptl/tls.h:
Include libc-pointer-arith.h instead of libc-internal.h.
* elf/get-dynamic-info.h, sysdeps/nacl/dl-map-segments.h
* sysdeps/x86_64/atomic-machine.h:
Add multiple include guard.
* crypt/md5.h: Test _LIBC with #if defined, not #if.
* dirent/opendir-tst1.c: Include sys/stat.h.
* dirent/tst-fdopendir.c: Include sys/stat.h.
* dirent/tst-fdopendir2.c: Include stdlib.h.
* dirent/tst-scandir.c: Include stdbool.h.
* elf/tst-auditmod1.c: Include link.h and stddef.h.
* elf/tst-tls15.c: Include stdlib.h.
* elf/tst-tls16.c: Include stdlib.h.
* elf/tst-tls17.c: Include stdlib.h.
* elf/tst-tls18.c: Include stdlib.h.
* iconv/tst-iconv6.c: Include endian.h.
* iconvdata/bug-iconv11.c: Include limits.h.
* io/test-utime.c: Include stdint.h.
* io/tst-faccessat.c: Include sys/stat.h.
* io/tst-fchmodat.c: Include sys/stat.h.
* io/tst-fchownat.c: Include sys/stat.h.
* io/tst-fstatat.c: Include sys/stat.h.
* io/tst-futimesat.c: Include sys/stat.h.
* io/tst-linkat.c: Include sys/stat.h.
* io/tst-mkdirat.c: Include sys/stat.h and stdbool.h.
* io/tst-mkfifoat.c: Include sys/stat.h and stdbool.h.
* io/tst-mknodat.c: Include sys/stat.h and stdbool.h.
* io/tst-openat.c: Include stdbool.h.
* io/tst-readlinkat.c: Include sys/stat.h.
* io/tst-renameat.c: Include sys/stat.h.
* io/tst-symlinkat.c: Include sys/stat.h.
* io/tst-unlinkat.c: Include stdbool.h.
* libio/bug-memstream1.c: Include stdlib.h.
* libio/bug-wmemstream1.c: Include stdlib.h.
* libio/tst-fwrite-error.c: Include stdlib.h.
* libio/tst-memstream1.c: Include stdlib.h.
* libio/tst-memstream2.c: Include stdlib.h.
* libio/tst-memstream3.c: Include stdlib.h.
* malloc/tst-interpose-aux.c: Include stdint.h.
* misc/tst-preadvwritev-common.c: Include sys/stat.h.
* nptl/tst-basic7.c: Include limits.h.
* nptl/tst-cancel25.c: Include pthread.h, not pthreadP.h.
* nptl/tst-cancel4.c: Include stddef.h, limits.h, and sys/stat.h.
* nptl/tst-cancel4_1.c: Include stddef.h.
* nptl/tst-cancel4_2.c: Include stddef.h.
* nptl/tst-cond16.c: Include limits.h.
Use sysconf(_SC_PAGESIZE) instead of __getpagesize.
* nptl/tst-cond18.c: Include limits.h.
Use sysconf(_SC_PAGESIZE) instead of __getpagesize.
* nptl/tst-cond4.c: Include stdint.h.
* nptl/tst-cond6.c: Include stdint.h.
* nptl/tst-stack2.c: Include limits.h.
* nptl/tst-stackguard1.c: Include stddef.h.
* nptl/tst-tls4.c: Include stdint.h. Don't include tls.h.
* nptl/tst-tls4moda.c: Include stddef.h.
Don't include stdio.h, unistd.h, or tls.h.
* nptl/tst-tls4modb.c: Include stddef.h.
Don't include stdio.h, unistd.h, or tls.h.
* nptl/tst-tls5.h: Include stddef.h. Don't include stdlib.h or tls.h.
* posix/tst-getaddrinfo2.c: Include stdio.h.
* posix/tst-getaddrinfo5.c: Include stdio.h.
* posix/tst-pathconf.c: Include sys/stat.h.
* posix/tst-posix_fadvise-common.c: Include stdint.h.
* posix/tst-preadwrite-common.c: Include sys/stat.h.
* posix/tst-regex.c: Include stdint.h.
Don't include spawn.h or spawn_int.h.
* posix/tst-regexloc.c: Don't include spawn.h or spawn_int.h.
* posix/tst-vfork3.c: Include sys/stat.h.
* resolv/tst-bug18665-tcp.c: Include stdlib.h.
* resolv/tst-res_hconf_reorder.c: Include stdlib.h.
* resolv/tst-resolv-search.c: Include stdlib.h.
* stdio-common/tst-fmemopen2.c: Include stdint.h.
* stdio-common/tst-vfprintf-width-prec.c: Include stdlib.h.
* stdlib/test-canon.c: Include sys/stat.h.
* stdlib/tst-tls-atexit.c: Include stdbool.h.
* string/test-memchr.c: Include stdint.h.
* string/tst-cmp.c: Include stdint.h.
* sysdeps/pthread/tst-timer.c: Include stdint.h.
* sysdeps/unix/sysv/linux/tst-sync_file_range.c: Include stdint.h.
* sysdeps/wordsize-64/tst-writev.c: Include limits.h and stdint.h.
* sysdeps/x86_64/fpu/math-tests-arch.h: Include cpu-features.h.
Don't include init-arch.h.
* sysdeps/x86_64/multiarch/test-multiarch.h: Include cpu-features.h.
Don't include init-arch.h.
* sysdeps/x86_64/tst-auditmod10b.c: Include link.h and stddef.h.
* sysdeps/x86_64/tst-auditmod3b.c: Include link.h and stddef.h.
* sysdeps/x86_64/tst-auditmod4b.c: Include link.h and stddef.h.
* sysdeps/x86_64/tst-auditmod5b.c: Include link.h and stddef.h.
* sysdeps/x86_64/tst-auditmod6b.c: Include link.h and stddef.h.
* sysdeps/x86_64/tst-auditmod6c.c: Include link.h and stddef.h.
* sysdeps/x86_64/tst-auditmod7b.c: Include link.h and stddef.h.
* time/clocktest.c: Include stdint.h.
* time/tst-posixtz.c: Include stdint.h.
* timezone/tst-timezone.c: Include stdint.h.
The code to set value passed a tunable_val_t, which when cast to
int32_t on big-endian gives the wrong value. Instead, use
tunable_val_t.numval instead, which can then be safely cast into
int32_t.
The child process of the tst-env-setuid process was failing correctly
with EXIT_UNSUPPORTED but the parent did not carry that status forward
and failed instead. This patch fixes this so that tests on nosuid
/tmp fails gracefully with UNSUPPORTED. Tested by making my tmpfs
nosuid.
* elf/tst-env-setuid.c (do_execve): Return EXIT_UNSUPPORTED in
parent if child exited in that manner. Print WEXITSTATUS
instead of the raw status.
(do_test_prep): Rename to do_test.
(do_test): Return the result of run_executable_sgid.
(TEST_FUNCTION_ARGV): Adjust.
In _dl_nothread_init_static_tls() and init_one_static_tls() we must not
touch the DTV of other threads since we do not have ownership of them.
The DTV need not be initialized at this point anyway since only LD/GD
accesses will use them. If LD/GD accesses occur they will take care to
initialize their own thread's DTV.
Concurrency comments were removed from the patch since they need to be
reworked along with a full description of DTV ownership and when it is
or is not safe to modify these structures.
Alexandre Oliva's original patch and discussion:
https://sourceware.org/ml/libc-alpha/2016-09/msg00512.html
A setxid program that uses a glibc with tunables disabled may pass on
GLIBC_TUNABLES as is to its child processes. If the child process
ends up using a different glibc that has tunables enabled, it will end
up getting access to unsafe tunables. To fix this, remove
GLIBC_TUNABLES from the environment for setxid process.
* sysdeps/generic/unsecvars.h: Add GLIBC_TUNABLES.
* elf/tst-env-setuid-tunables.c
(test_child_tunables)[!HAVE_TUNABLES]: Verify that
GLIBC_TUNABLES is removed in a setgid process.
Florian Weimer pointed out that we have three different kinds of
environment variables (and hence tunables):
1. Variables that are removed for setxid processes
2. Variables that are ignored in setxid processes but is passed on to
child processes
3. Variables that are passed on to child processes all the time
Tunables currently only does (2) and (3) when it should be doing (1)
for MALLOC_CHECK_. This patch enhances the is_secure flag in tunables
to an enum value that can specify which of the above three categories
the tunable (and its envvar alias) belongs to.
The default is for tunables to be in (1). Hence, all of the malloc
tunables barring MALLOC_CHECK_ are explicitly specified to belong to
category (2). There were discussions around abolishing category (2)
completely but we can do that as a separate exercise in 2.26.
Tested on x86_64 to verify that there are no regressions.
[BZ #21073]
* elf/dl-tunable-types.h (tunable_seclevel_t): New enum.
* elf/dl-tunables.c (tunables_strdup): Remove.
(get_next_env): Also return the previous envp.
(parse_tunables): Erase tunables of category
TUNABLES_SECLEVEL_SXID_ERASE.
(maybe_enable_malloc_check): Make MALLOC_CHECK_
TUNABLE_SECLEVEL_NONE if /etc/setuid-debug is accessible.
(__tunables_init)[TUNABLES_FRONTEND ==
TUNABLES_FRONTEND_valstring]: Update GLIBC_TUNABLES envvar
after parsing.
[TUNABLES_FRONTEND != TUNABLES_FRONTEND_valstring]: Erase
tunable envvars of category TUNABLES_SECLEVEL_SXID_ERASE.
* elf/dl-tunables.h (struct _tunable): Change member is_secure
to security_level.
* elf/dl-tunables.list: Add security_level annotations for all
tunables.
* scripts/gen-tunables.awk: Recognize and generate enum values
for security_level.
* elf/tst-env-setuid.c: New test case.
* elf/tst-env-setuid-tunables: new test case.
* elf/Makefile (tests-static): Add them.
(tunable_set_val_if_valid_range_signed) ... this, and ...
(tunable_set_val_if_valid_range_unsigned) ... this.
(tunable_initialize): Call the correct one of the above based on type.
The condition when the value of an envvar is empty (not just '\0'),
the loop in tunables_init gets stuck infinitely because envp is not
incremented. Fix that by always incrementing envp in the loop.
Added test case (tst-empty-env.c) verifies the fix when the source is
configured with --enable-hardcoded-path-in-tests, thanks Josh Stone for
providing the test case. Verified on x86_64.
* elf/dl-tunables (get_next_env): Always advance envp.
* stdlib/tst-empty-env.c: New test case.
* stdlib/Makefile (tests): Use it.
Building 64-bit glibc with GCC mainline fails with:
../elf/sotruss-lib.c: In function 'la_version':
../elf/sotruss-lib.c:91:28: error: '%lu' directive output may be truncated writing between 1 and 20 bytes into a region of size 11 [-Werror=format-truncation=]
snprintf (endp, 12, ".%lu", (unsigned long int) pid);
^~~
../elf/sotruss-lib.c:91:26: note: using the range [1, 18446744073709551615] for directive argument
snprintf (endp, 12, ".%lu", (unsigned long int) pid);
^~~~~~
../elf/sotruss-lib.c:91:6: note: format output between 3 and 22 bytes into a destination of size 12
snprintf (endp, 12, ".%lu", (unsigned long int) pid);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Pids from getpid cannot actually be negative, but the compiler doesn't
know this. Other places in this file use (signed) long int for
printing, so this patch makes this place do so as well. Then it
increases the buffer size by one byte to allow for the minus sign that
can't actually occur. It doesn't seem worth using diagnostic pragmas
to save one byte; other place in this file just use a cruder 3 *
sizeof (pid_t) calculation for number of digits.
Tested with GCC mainline with compilation for aarch64 with
build-many-glibcs.py, and with glibc testsuite for x86_64 (built with
GCC 6).
* elf/sotruss-lib.c (init): Increase space allocated for pid by
one byte. Print it with %ld, cast to long int.
Builds with --enable-tunables failed on i686 because a call to getenv
got snuck into tunables, which pulled in strncmp. This patch fixes
this build failure by making the glibc.malloc.check check even
simpler. The previous approach was convoluted where the tunable was
disabled using an unsetenv and overwriting the tunable value with
colons. The easier way is to simply mark the tunable as insecure by
default (i.e. won't be read for AT_SECURE programs) and then enabled
only when the /etc/suid-debug file is found.
This also ends up removing a bunch of functions that were specially
reimplemented (strlen, unsetenv) to avoid calling into string
routines.
Tested on x86_64 and i686.
* elf/dl-tunables.c (tunables_unsetenv): Remove function.
(min_strlen): Likewise.
(disable_tunable): Likewise.
(maybe_disable_malloc_check): Rename to
maybe_enable_malloc_check.
(maybe_enable_malloc_check): Enable glibc.malloc.check tunable
if /etc/suid-debug file exists.
(__tunables_init): Update caller.
* elf/dl-tunables.list (glibc.malloc.check): Don't mark as
secure.
This patch increases timeouts on some tests I've observed timing out.
elf/tst-tls13 and iconvdata/tst-loading both dynamically load many
objects and so are slow when testing over NFS. They had timeouts set
from before the default changed from 2 to 20 seconds; this patch
removes those old settings, so effectively increasing the timeout to
20 seconds (from 3 and 10 seconds respectively).
malloc/tst-malloc-thread-fail.c and malloc/tst-mallocfork2.c are slow
on slow systems and so I set a fairly arbitrary 100 second timeout,
which seems to suffice on the system where I saw them timing out.
nss/tst-cancel-getpwuid_r.c and nss/tst-nss-getpwent.c are slow on
systems with a large passwd file; I set timeouts that empirically
worked for me. (It seems tst-cancel-getpwuid_r.c is hitting the
100000 getpwuid_r call limit in my testing, with each call taking a
bit over 0.007 seconds, so 700 seconds for the test.)
* elf/tst-tls13.c (TIMEOUT): Remove.
* iconvdata/tst-loading.c (TIMEOUT): Likewise.
* malloc/tst-malloc-thread-fail.c (TIMEOUT): Increase to 100.
* malloc/tst-mallocfork2.c (TIMEOUT): Define to 100.
* nss/tst-cancel-getpwuid_r.c (TIMEOUT): Define to 900.
* nss/tst-nss-getpwent.c (TIMEOUT): Define to 300.
elf/Makefile passes arguments to tst-ldconfig-X.sh that are different
from what it expects, so resulting in the test failing in cross
testing. This patch corrects the arguments passed (the script itself
has correct logic for cross testing, it's just the Makefile that's
wrong).
Tested for powerpc (cross testing) and for x86_64 (native testing).
* elf/Makefile ($(objpfx)tst-ldconfig-X.out): Correct arguments
passed to tst-ldconfig-X.sh.
At the GNU Tools Cauldron 2016, the state of the current tunables
patchset was considered OK with the addition of a way to select the
frontend to be used for the tunables. That is, to avoid being locked
in to one type of frontend initially, it should be possible to build
tunables with a different frontend with something as simple as a
configure switch.
To that effect, this patch enhances the --enable-tunables option to
accept more values than just 'yes' or 'no'. The current frontend (and
default when enable-tunables is 'yes') is called 'valstring', to
select the frontend where a single environment variable is set to a
colon-separated value string. More such frontends can be added in
future.
* Makeconfig (have-tunables): Check for non-negative instead
of positive.
* configure.ac: Add 'valstring' as a valid value for
--enable-tunables.
* configure: Regenerate.
* elf/Makefile (have-tunables): Check for non-negative instead
of positive.
(CPPFLAGS-dl-tunables.c): Define TUNABLES_FRONTEND for
dl-tunables.c.
* elf/dl-tunables.c (GLIBC_TUNABLES): Define only when
TUNABLES_FRONTEND == TUNABLES_FRONTEND_valstring.
(tunables_strdup): Likewise.
(disable_tunables): Likewise.
(parse_tunables): Likewise.
(__tunables_init): Process GLIBC_TUNABLES envvar only when.
TUNABLES_FRONTEND == TUNABLES_FRONTEND_valstring.
* elf/dl-tunables.h (TUNABLES_FRONTEND_valstring): New macro.
(TUNABLES_FRONTEND_yes): New macro, define as
TUNABLES_FRONTEND_valstring by default.
* manual/install.texi: Document new acceptable values for
--enable-tunables.
* INSTALL: Regenerate.
Read tunables values from the users using the GLIBC_TUNABLES
environment variable. The value of this variable is a colon-separated
list of name=value pairs. So a typical string would look like this:
GLIBC_TUNABLES=glibc.malloc.mmap_threshold=2048:glibc.malloc.trim_threshold=1024
* config.make.in (have-loop-to-function): Define.
* elf/Makefile (CFLAGS-dl-tunables.c): Add
-fno-tree-loop-distribute-patterns.
* elf/dl-tunables.c: Include libc-internals.h.
(GLIBC_TUNABLES): New macro.
(tunables_strdup): New function.
(parse_tunables): New function.
(min_strlen): New function.
(__tunables_init): Use the new functions and macro.
(disable_tunable): Disable tunable from GLIBC_TUNABLES.
* malloc/tst-malloc-usable-tunables.c: New test case.
* malloc/tst-malloc-usable-static-tunables.c: New test case.
* malloc/Makefile (tests, tests-static): Add tests.
The tunables framework allows us to uniformly manage and expose global
variables inside glibc as switches to users. tunables/README has
instructions for glibc developers to add new tunables.
Tunables support can be enabled by passing the --enable-tunables
configure flag to the configure script. This patch only adds a
framework and does not pose any limitations on how tunable values are
read from the user. It also adds environment variables used in malloc
behaviour tweaking to the tunables framework as a PoC of the
compatibility interface.
* manual/install.texi: Add --enable-tunables option.
* INSTALL: Regenerate.
* README.tunables: New file.
* Makeconfig (CPPFLAGS): Define TOP_NAMESPACE.
(before-compile): Generate dl-tunable-list.h early.
* config.h.in: Add HAVE_TUNABLES.
* config.make.in: Add have-tunables.
* configure.ac: Add --enable-tunables option.
* configure: Regenerate.
* csu/init-first.c (__libc_init_first): Move
__libc_init_secure earlier...
* csu/init-first.c (LIBC_START_MAIN):... to here.
Include dl-tunables.h, libc-internal.h.
(LIBC_START_MAIN) [!SHARED]: Initialize tunables for static
binaries.
* elf/Makefile (dl-routines): Add dl-tunables.
* elf/Versions (ld): Add __tunable_set_val to GLIBC_PRIVATE
namespace.
* elf/dl-support (_dl_nondynamic_init): Unset MALLOC_CHECK_
only when !HAVE_TUNABLES.
* elf/rtld.c (process_envvars): Likewise.
* elf/dl-sysdep.c [HAVE_TUNABLES]: Include dl-tunables.h
(_dl_sysdep_start): Call __tunables_init.
* elf/dl-tunable-types.h: New file.
* elf/dl-tunables.c: New file.
* elf/dl-tunables.h: New file.
* elf/dl-tunables.list: New file.
* malloc/tst-malloc-usable-static.c: New test case.
* malloc/Makefile (tests-static): Add it.
* malloc/arena.c [HAVE_TUNABLES]: Include dl-tunables.h.
Define TUNABLE_NAMESPACE.
(DL_TUNABLE_CALLBACK (set_mallopt_check)): New function.
(DL_TUNABLE_CALLBACK_FNDECL): New macro. Use it to define
callback functions.
(ptmalloc_init): Set tunable values.
* scripts/gen-tunables.awk: New file.
* sysdeps/mach/hurd/dl-sysdep.c: Include dl-tunables.h.
(_dl_sysdep_start): Call __tunables_init.
The previous commit prevented rtld itself from being built with
-fstack-protector, but this is not quite enough. We identify which
objects belong in rtld via a test link and analysis of the resulting
mapfile. That link is necessarily done against objects that are
stack-protected, so drags in __stack_chk_fail_local, __stack_chk_fail,
and all the libc and libio code they use.
To stop this happening, use --defsym in the test librtld.map-production
link to force the linker to predefine these two symbols (to 0, but it
could be to anything). (In a real link, this would of course be
catastrophic, but these object files are never used for anything else.)
When dynamically linking, ifunc resolvers are called before TLS is
initialized, so they cannot be safely stack-protected.
We avoid disabling stack-protection on large numbers of files by
using __attribute__ ((__optimize__ ("-fno-stack-protector")))
to turn it off just for the resolvers themselves. (We provide
the attribute even when statically linking, because we will later
use it elsewhere too.)
There is at least one use case where during exit a library destructor
might call dlclose() on a valid handle and have it fail with an
assertion. We must allow this case, it is a valid handle, and dlclose()
should not fail with an assert. In the future we might be able to return
an error that the dlclose() could not be completed because the opened
library has already been unloaded and destructors have run as part of
exit processing.
For more details see:
https://www.sourceware.org/ml/libc-alpha/2016-12/msg00859.html
Commit 7a5e3d9d63 (elf: Assume TLS is
initialized in _dl_map_object_from_fd) removed the last call of
_dl_tls_setup, but did not remove the function itself.
The new test driver in <support/test-driver.c> has feature parity with
the old one. The main difference is that its hooking mechanism is
based on functions and function pointers instead of macros. This
commit also implements a new environment variable, TEST_COREDUMPS,
which disables the code which disables coredumps (that is, it enables
them if the invocation environment has not disabled them).
<test-skeleton.c> defines wrapper functions so that it is possible to
use existing macros with the new-style hook functionality.
This commit changes only a few test cases to the new test driver, to
make sure that it works as expected.
Some configurations may use NSS cryptographic routines but have no
static library for those routines. The following changes allow glibc to
be built and tested with --enable-nss-crypt, but without having a static
NSS library. At a high level the change does two things:
(1) Detect at configure time if static NSS crypto libraries are
available. Assumes libfreebl3.a (instead of the existing Fedora
libfreebl.a which is incomplete) which matches libfreebl3.so.
(2) If static NSS crypto libraries are _not_ available then adjust the
way in which we build tst-linkall-static. This includes excluding a
reference to crypt and not linking against libcrypt.a, all of which
will fail otherwise.
Testing assumptions:
* Static library is named libfreebl3.a (not libfreebl.a as is currently
provided in Fedora), matching libfreebl3.so shared link name.
Tested on x86_64 on Fedora with:
(a) --enable-nss-crypt, with no static NSS library support: PASS
(previous FAIL)
(b) --enable-nss-crypt, with faked static NSS library support: PASS
(unsupported)
* Requires changing elf/Makefile to include a stub
/lib64/libfreebl3.a for testing purposes.
(c) --disable-nss-crypt: PASS
(default)
No regressions on x86_64.
For details see:
https://www.sourceware.org/ml/libc-alpha/2016-11/msg00647.html
The first dlopen ("tst-latepthreadmod.so", RTLD_LOCAL | RTLD_LAZY) call
in elf/tst-latepthread.c fails on s390x with "error: dlopen failed:
.../build-s390x/elf/tst-latepthreadmod.so:
undefined symbol: this_function_is_not_defined".
In elf/tst-latepthreadmod.c, this_function_is_not_defined is a sibling
call which leads to a R_390_GLOB_DAT relocation in .rela.dyn instead of
a R_390_JMP_SLOT in .rela.plt.
As RTLD_LAZY skips the JMP_SLOT relocations, but not GLOB_DAT ones,
the dlopen call fails. If elf/tst-latepthreadmod.c is build with
-fno-optimize-sibling-calls, a JMP_SLOT relocation is generated for
this_function_is_not_defined and the test passes.
ChangeLog:
* elf/Makefile (CFLAGS-tst-latepthreadmod.c):
Add -fno-optimize-sibling-calls.
It is no longer needed since commit 6c444ad6e9
(elf: Do not use memalign for TCB/TLS blocks allocation [BZ #17730]).
Applications do not link against ld.so and will use the definition in
libc.so, so there is no ABI impact.
This change moves the main implementation of _dl_catch_error,
_dl_signal_error to libc.so, where TLS variables can be used
directly. This removes a writable function pointer from the
rtld_global variable.
For use during initial relocation, minimal implementations of these
functions are provided in ld.so. These are eventually interposed
by the libc.so implementations. This is implemented by compiling
elf/dl-error-skeleton.c twice, via elf/dl-error.c and
elf/dl-error-minimal.c.
As a side effect of this change, the static version of dl-error.c
no longer includes support for the
_dl_signal_cerror/_dl_receive_error mechanism because it is only
used in ld.so.
The function _dl_addr_inside_object is simplified by removing
the conditional 'reladdr - l->l_phdr[n].p_vaddr >= 0' which is
always true. The function is refactored into it's own object file
and a unit test added to verify the correct behaviour of the
function.
An earlier fix for TLS dropped early initialization of DTV entries for
modules using static TLS, leaving it for __tls_get_addr to set them
up. That worked on platforms that require the GD access model to be
relaxed to LE in the main executable, but it caused a regression on
platforms that allow GD in the main executable, particularly in
statically-linked programs: they use a custom __tls_get_addr that does
not update the DTV, which fails when the DTV early initialization is
not performed.
In static programs, __libc_setup_tls performs the DTV initialization
for the main thread, but the DTV of other threads is set up in
_dl_allocate_tls_init, so that's the fix that matters.
Restoring the initialization in the remaining functions modified by
this patch was just for uniformity. It's not clear that it is ever
needed: even on platforms that allow GD in the main executable, the
dynamically-linked version of __tls_get_addr would set up the DTV
entries, even for static TLS modules, while updating the DTV counter.
for ChangeLog
[BZ #19826]
* elf/dl-tls.c (_dl_allocate_tls_init): Restore DTV early
initialization of static TLS entries.
* elf/dl-reloc.c (_dl_nothread_init_static_tls): Likewise.
* nptl/allocatestack.c (init_one_static_tls): Likewise.
The commit b632bdd3 moved the setting of the DF_1_NODELETE flag earlier
in the dl_open_worker function. However when calling dlopen with both
RTLD_NODELETE and RTLD_NOLOAD, the pointer returned by _dl_map_object is
NULL. This condition is checked just after setting the flag, while it
should be done before. Fix that.
Changelog:
[BZ #19810]
* elf/dl-open.c (dl_open_worker): Set DF_1_NODELETE flag later.
* elf/tst-noload.c: New test case.
* elf/Makefile (tests): Add tst-noload.
Instead, call malloc and explicitly align the pointer.
There is no external location to store the original (unaligned)
pointer, and this commit increases the allocation size to store
the pointer at a fixed location relative to the TCB pointer.
The manual alignment means that some space goes unused which
was previously made available for subsequent allocations.
However, in the TLS_DTV_AT_TP case, the manual alignment code
avoids aligning the pre-TCB to the TLS block alignment. (Even
while using memalign, the allocation had some unused padding
in front.)
This concludes the removal of memalign calls from the TLS code,
and the new tst-tls3-malloc test verifies that only core malloc
routines are used.
Instead of a flag which indicates the pointer can be freed, dtv_t
now includes the pointer which should be freed. Due to padding,
the size of dtv_t does not increase.
To avoid using memalign, the new allocate_dtv_entry function
allocates a sufficiently large buffer so that a sub-buffer
can be found in it which starts with an aligned pointer. Both
the aligned and original pointers are kept, the latter for calling
free later.
The dynamic linker currently uses __libc_memalign for TLS-related
allocations. The goal is to switch to malloc instead. If the minimal
malloc follows the ABI fundamental alignment, we can assume that malloc
provides this alignment, and thus skip explicit alignment in a few
cases as an optimization.
It was requested on libc-alpha that MALLOC_ALIGNMENT should be used,
although this results in wasted space if MALLOC_ALIGNMENT is larger
than the fundamental alignment. (The dynamic linker cannot assume
that the non-minimal malloc will provide an alignment of
MALLOC_ALIGNMENT; the ABI provides _Alignof (max_align_t) only.)
Since _dl_tlsdesc_dynamic is called via PLT, we need to add 8 bytes for
push in the PLT entry to align the stack.
[BZ #20309]
* configure.ac (have-mtls-dialect-gnu2): Set to yes if
-mtls-dialect=gnu2 works.
* configure: Regenerated.
* elf/Makefile [have-mtls-dialect-gnu2 = yes]
(tests): Add tst-gnu2-tls1.
(modules-names): Add tst-gnu2-tls1mod.
($(objpfx)tst-gnu2-tls1): New.
(tst-gnu2-tls1mod.so-no-z-defs): Likewise.
(CFLAGS-tst-gnu2-tls1mod.c): Likewise.
* elf/tst-gnu2-tls1.c: New file.
* elf/tst-gnu2-tls1mod.c: Likewise.
* sysdeps/x86_64/dl-tlsdesc.S (_dl_tlsdesc_dynamic): Add 8
bytes for push in the PLT entry to align the stack.
In a reference to PR ld/19908 make ld.so respect symbol export classes
aka visibility and treat STV_HIDDEN and STV_INTERNAL symbols as local,
preventing such symbols from preempting exported symbols.
According to the ELF gABI[1] neither STV_HIDDEN nor STV_INTERNAL symbols
are supposed to be present in linked binaries:
"A hidden symbol contained in a relocatable object must be either
removed or converted to STB_LOCAL binding by the link-editor when the
relocatable object is included in an executable file or shared object."
"An internal symbol contained in a relocatable object must be either
removed or converted to STB_LOCAL binding by the link-editor when the
relocatable object is included in an executable file or shared object."
however some GNU binutils versions produce such symbols in some cases.
PR ld/19908 is one and we also have this note in scripts/abilist.awk:
so clearly there is linked code out there which contains such symbols
which is prone to symbol table misinterpretation, and it'll be more
productive if we handle this gracefully, under the Robustness Principle:
"be liberal in what you accept, and conservative in what you produce",
especially as this is a simple (STV_HIDDEN|STV_INTERNAL) => STB_LOCAL
mapping.
References:
[1] "System V Application Binary Interface - DRAFT - 24 April 2001",
The Santa Cruz Operation, Inc., "Symbol Table",
<http://www.sco.com/developers/gabi/2001-04-24/ch4.symtab.html>
* sysdeps/generic/ldsodefs.h
(dl_symbol_visibility_binds_local_p): New inline function.
* elf/dl-addr.c (determine_info): Treat hidden and internal
symbols as local.
* elf/dl-lookup.c (do_lookup_x): Likewise.
* elf/dl-reloc.c (RESOLVE_MAP): Likewise.
The EM_BPF number has been officially assigned, though it
has not yet been posted to the gabi webpage yet.
* elf/elf.h (EM_BPF): New.
(EM_NUM): Update.
(R_BPF_NONE, R_BPF_MAP_FD): New.
__libc_memalign in ld.so allocates one page at a time and tries to
optimize consecutive __libc_memalign calls by hoping that the next
mmap is after the current memory allocation.
However, the kernel hands out mmap addresses in top-down order, so
this optimization in practice never happens, with the result that we
have more mmap calls and waste a bunch of space for each __libc_memalign.
This change makes __libc_memalign to mmap one page extra. Worst case,
the kernel never puts a backing page behind it, but best case it allows
__libc_memalign to operate much much better. For elf/tst-align --direct,
it reduces number of mmap calls from 12 to 9.
* elf/dl-minimal.c (__libc_memalign): Mmap one extra page.
This patch fixes the new test tst-dlsym-error build on aarch64
(and possible other architectures as well) due missing strchrnul
definition.
* elf/tst-dlsym-error.c: Include <string.h> for strchrnul.
* elf/dl-lookup.c (_dl_lookup_symbol_x): Report error even if
skip_map != NULL.
* elf/tst-dlsym-error.c: New file.
* elf/Makefile (tests): Add tst-dlsym-error.
(tst-dlsym-error): Link against libdl.
When using sln on some filesystems which return 64-bit inodes,
the stat call might fail during install like so:
.../elf/sln .../elf/symlink.list
/lib32/libc.so.6: invalid destination: Value too large for defined data type
/lib32/ld-linux.so.2: invalid destination: Value too large for defined data type
Makefile:104: recipe for target 'install-symbolic-link' failed
Switch to using stat64 all the time to avoid this.
URL: https://bugs.gentoo.org/576396
In 1999 the project split "localedir" into "localedir" (path to compiled
locale archives) and "msgcatdir" (path to message catalogs). This
predates the 2002 change in the GNU Coding Standard to document the use
of "localedir" for the path to the message catalogs. It appears that
newlib, gcc, and several other projects also used "msgcatdir" at one
point or another in the past, and so it is in line with historical
precedent that glibc would also use "msgcatdir." However, given that the
GNU Coding Standard uses "localedir", we will switch to that for
consistency as a GNU project. Previous uses of --localdir didn't work
anyway (see bug 14259).
I am committing this patch in the understanding that nobody would object
to fixing #14259 as part of aligning our variable usage to the GNU
Coding Standard.
Given that previous "localedir" uses were converted to "complocaledir"
by [1], we can now convert "msgcatdir" to "localedir" and complete the
transition. With an addition to config.make.in we also fix bug 14259 and
allow users to specify the locale dependent data directory with
"--localedir" at configure time. There is still no way to control at
configure time the location of the *compiled* locale directory.
Tested on x86_64 with no regressions.
Tested using "--localedir" to specify alternate locale dependent data
directory and verified with "make install DESTDIR=/tmp/glibc".
[1] 90fe682d30
