Commit Graph

124 Commits

Author SHA1 Message Date
Palmer Dabbelt
96d1b9ac23 RISC-V: Fix the static-PIE non-relocated object check
The value of l_scope is only valid post relocation, so this original
check was triggering undefined behavior.  Instead just directly check to
see if the object has been relocated, at which point using l_scope is
safe.

Reported-by: Andreas Schwab <schwab@suse.de>
Closes: BZ #31317
Fixes: e0590f41fe ("RISC-V: Enable static-pie.")
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-03-25 15:17:13 +01:00
Darius Rad
f44f3aed31 riscv: Update nofpu libm test ulps
Fix two test failures.

Reviewed-by: Florian Weimer <fweimer@redhat.com>
2024-03-18 11:28:50 +01:00
Adhemerval Zanella
2149da3683 riscv: Fix alignment-ignorant memcpy implementation
The memcpy optimization (commit 587a1290a1) has a series
of mistakes:

  - The implementation is wrong: the chunk size calculation is wrong
    leading to invalid memory access.

  - It adds ifunc supports as default, so --disable-multi-arch does
    not work as expected for riscv.

  - It mixes Linux files (memcpy ifunc selection which requires the
    vDSO/syscall mechanism)  with generic support (the memcpy
    optimization itself).

  - There is no __libc_ifunc_impl_list, which makes testing only
    check the selected implementation instead of all supported
    by the system.

This patch also simplifies the required bits to enable ifunc: there
is no need to memcopy.h; nor to add Linux-specific files.

The __memcpy_noalignment tail handling now uses a branchless strategy
similar to aarch64 (overlap 32-bits copies for sizes 4..7 and byte
copies for size 1..3).

Checked on riscv64 and riscv32 by explicitly enabling the function
on __libc_ifunc_impl_list on qemu-system.

Changes from v1:
* Implement the memcpy in assembly to correctly handle RISCV
  strict-alignment.
Reviewed-by: Evan Green <evan@rivosinc.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-03-12 14:38:08 -03:00
Evan Green
587a1290a1
riscv: Add and use alignment-ignorant memcpy
For CPU implementations that can perform unaligned accesses with little
or no performance penalty, create a memcpy implementation that does not
bother aligning buffers. It will use a block of integer registers, a
single integer register, and fall back to bytewise copy for the
remainder.

Signed-off-by: Evan Green <evan@rivosinc.com>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-03-01 07:15:01 -08:00
Evan Green
a29bb320a1
riscv: Enable multi-arg ifunc resolvers
RISC-V is apparently the first architecture to pass more than one
argument to ifunc resolvers. The helper macros in libc-symbols.h,
__ifunc_resolver(), __ifunc(), and __ifunc_hidden(), are incompatible
with this. These macros have an "arg" (non-final) parameter that
represents the parameter signature of the ifunc resolver. The result is
an inability to pass the required comma through in a single preprocessor
argument.

Rearrange the __ifunc_resolver() macro to be variadic, and pass the
types as those variable parameters. Move the guts of __ifunc() and
__ifunc_hidden() into new macros, __ifunc_args(), and
__ifunc_args_hidden(), that pass the variable arguments down through to
__ifunc_resolver(). Then redefine __ifunc() and __ifunc_hidden(), which
are used in a bunch of places, to simply shuffle the arguments down into
__ifunc_args[_hidden]. Finally, define a riscv-ifunc.h header, which
provides convenience macros to those looking to write ifunc selectors
that use both arguments.

Signed-off-by: Evan Green <evan@rivosinc.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-03-01 07:14:59 -08:00
Evan Green
78308ce77a
riscv: Add __riscv_hwprobe pointer to ifunc calls
The new __riscv_hwprobe() function is designed to be used by ifunc
selector functions. This presents a challenge for applications and
libraries, as ifunc selectors are invoked before all relocations have
been performed, so an external call to __riscv_hwprobe() from an ifunc
selector won't work. To address this, pass a pointer to the
__riscv_hwprobe() function into ifunc selectors as the second
argument (alongside dl_hwcap, which was already being passed).

Include a typedef as well for convenience, so that ifunc users don't
have to go through contortions to call this routine. Users will need to
remember to check the second argument for NULL, to account for older
glibcs that don't pass the function.

Signed-off-by: Evan Green <evan@rivosinc.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-03-01 07:14:58 -08:00
Joseph Myers
42cc619dfb Refer to C23 in place of C2X in glibc
WG14 decided to use the name C23 as the informal name of the next
revision of the C standard (notwithstanding the publication date in
2024).  Update references to C2X in glibc to use the C23 name.

This is intended to update everything *except* where it involves
renaming files (the changes involving renaming tests are intended to
be done separately).  In the case of the _ISOC2X_SOURCE feature test
macro - the only user-visible interface involved - support for that
macro is kept for backwards compatibility, while adding
_ISOC23_SOURCE.

Tested for x86_64.
2024-02-01 11:02:01 +00:00
Andreas Schwab
6edaa12b41 riscv: add support for static PIE
In order to support static PIE the startup code must avoid relocations
before __libc_start_main is called.
2024-01-22 14:58:23 +01:00
Yanzhang Wang
e0590f41fe RISC-V: Enable static-pie.
This patch referents the commit 374cef3 to add static-pie support. And
because the dummy link map is used when relocating ourselves, so need
not to set __global_pointer$ at this time.

It will also check whether toolchain supports to build static-pie.
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2024-01-12 15:11:45 -03:00
Paul Eggert
dff8da6b3e Update copyright dates with scripts/update-copyrights 2024-01-01 10:53:40 -08:00
Aurelien Jarno
6b32696116 RISC-V: Add support for dl_runtime_profile (BZ #31151)
Code is mostly inspired from the LoongArch one, which has a similar ABI,
with minor changes to support riscv32 and register differences.

This fixes elf/tst-sprof-basic. This also fixes elf/tst-audit1,
elf/tst-audit2 and elf/tst-audit8 with recent binutils snapshots when
--enable-bind-now is used.

Resolves: BZ #31151

Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-12-30 11:00:10 +01:00
Adhemerval Zanella
802aef27b2 riscv: Fix feenvupdate with FE_DFL_ENV (BZ 31022)
libc_feupdateenv_riscv should check for FE_DFL_ENV, similar to
libc_fesetenv_riscv.

Also extend the test-fenv.c to test fenvupdate.

Checked on riscv under qemu-system.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-12-19 15:12:38 -03:00
Christoph Müllner
3d6fcf1bd7 riscv: Add support for XTheadBb in string-fz[a,i].h
XTheadBb has similar instructions like Zbb, which allow optimized
string processing:
* th.ff0: find-first zero is a CLZ instruction.
* th.tstnbz: Similar like orc.b, but with a bit-inverted result.

The instructions are documented here:
  https://github.com/T-head-Semi/thead-extension-spec/tree/master/xtheadbb

These instructions can be found in the T-Head C906 and the C910.

Tested with the string tests.

Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2023-09-06 09:27:43 -03:00
Aurelien Jarno
7fcdc2380c riscv: Update rvd libm test ulps
Generated on a VisionFive 2 board running Linux version 6.4.2 and
GCC 13.1.0.

Needed due to commit cf7ffdd8a5 ("added pair of inputs for hypotf in
binary32").
2023-07-22 15:55:33 +02:00
Siddhesh Poyarekar
c6cb8783b5 configure: Use autoconf 2.71
Bump autoconf requirement to 2.71 to allow regenerating configure on
more recent distributions.  autoconf 2.71 has been in Fedora since F36
and is the current version in Debian stable (bookworm).  It appears to
be current in Gentoo as well.

All sysdeps configure and preconfigure scripts have also been
regenerated; all changes are trivial transformations that do not affect
functionality.

Signed-off-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2023-07-17 10:08:10 -04:00
Florian Weimer
bf88b47ecb Revert "riscv: Resolve symbols directly for symbols with STO_RISCV_VARIANT_CC."
This reverts commit 117e8b341c.

Reason for revert: Causes elf/tst-glibcelf and elf/tst-relro-*
to fail on all architectures.
2023-05-07 14:16:03 +02:00
Hsiangkai Wang
117e8b341c
riscv: Resolve symbols directly for symbols with STO_RISCV_VARIANT_CC.
In some cases, we do not want to go through the resolver for function
calls. For example, functions with vector arguments will use vector
registers to pass arguments. In the resolver, we do not save/restore the
vector argument registers for lazy binding efficiency. To avoid ruining
the vector arguments, functions with vector arguments will not go
through the resolver.

To achieve the goal, we will annotate the function symbols with
STO_RISCV_VARIANT_CC flag and add DT_RISCV_VARIANT_CC tag in the dynamic
section. In the first pass on PLT relocations, we do not set up to call
_dl_runtime_resolve. Instead, we resolve the functions directly.

Signed-off-by: Hsiangkai Wang <kai.wang@sifive.com>
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Link: https://inbox.sourceware.org/libc-alpha/20230314162512.35802-1-kito.cheng@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-28 07:02:42 -07:00
Adhemerval Zanella
25788431c0 riscv: Add string-fza.h and string-fzi.h
It uses the bitmanip extension to optimize index_fist and index_last
with clz/ctz (using generic implementation that routes to compiler
builtin) and orc.b to check null bytes.

Checked the string test on riscv64 user mode.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
2023-02-06 16:19:35 -03:00
Joseph Myers
6d7e8eda9b Update copyright dates with scripts/update-copyrights 2023-01-06 21:14:39 +00:00
Florian Weimer
1f34a23288 elf: Introduce <dl-call_tls_init_tp.h> and call_tls_init_tp (bug 29249)
This makes it more likely that the compiler can compute the strlen
argument in _startup_fatal at compile time, which is required to
avoid a dependency on strlen this early during process startup.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2022-11-03 17:28:03 +01:00
Letu Ren
0cc0033ef1 stdlib/strfrom: Add copysign to fix NAN issue on riscv (BZ #29501)
According to the specification of ISO/IEC TS 18661-1:2014,

The strfromd, strfromf, and strfroml functions are equivalent to
snprintf(s, n, format, fp) (7.21.6.5), except the format string contains only
the character %, an optional precision that does not contain an asterisk *, and
one of the conversion specifiers a, A, e, E, f, F, g, or G, which applies to
the type (double, float, or long double) indicated by the function suffix
(rather than  by a length modifier). Use of these functions with any other 20
format string results in undefined behavior.

strfromf will convert the arguement with type float to double first.

According to the latest version of IEEE754 which is published in 2019,

Conversion of a quiet NaN from a narrower format to a wider format in the same
radix, and then back to the same narrower format, should not change the quiet
NaN payload in any way except to make it canonical.

When either an input or result is a NaN, this standard does not interpret the
sign of a NaN. However, operations on bit strings—copy, negate, abs,
copySign—specify the sign bit of a NaN result, sometimes based upon the sign
bit of a NaN operand. The logical predicates totalOrder and isSignMinus are
also affected by the sign bit of a NaN operand. For all other operations, this
standard does not specify the sign bit of a NaN result, even when there is only
one input NaN, or when the NaN is produced from an invalid operation.

converting NAN or -NAN with type float to double doesn't need to keep
the signbit. As a result, this test case isn't mandatory.

The problem is that according to RISC-V ISA manual in chapter 11.3 of
riscv-isa-20191213,

Except when otherwise stated, if the result of a floating-point operation is
NaN, it is the canonical NaN. The canonical NaN has a positive sign and all
significand bits clear except the MSB, a.k.a. the quiet bit. For
single-precision floating-point, this corresponds to the pattern 0x7fc00000.

which means that conversion -NAN from float to double won't keep the signbit.

Since glibc ought to be consistent here between types and architectures, this
patch adds copysign to fix this problem if the string is NAN. This patch
adds two different functions under sysdeps directory to work around the
issue.

This patch has been tested on x86_64 and riscv64.

Resolves: BZ #29501

v2: Change from macros to different inline functions.
v3: Add unlikely check to isnan.
v4: Fix wrong commit message header.
v5: Fix style: add space before parentheses.
v6: Add copyright.
Signed-off-by: Letu Ren <fantasquex@gmail.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-10-28 11:35:20 -03:00
Florian Weimer
58548b9d68 Use PTR_MANGLE and PTR_DEMANGLE unconditionally in C sources
In the future, this will result in a compilation failure if the
macros are unexpectedly undefined (due to header inclusion ordering
or header inclusion missing altogether).

Assembler sources are more difficult to convert.  In many cases,
they are hand-optimized for the mangling and no-mangling variants,
which is why they are not converted.

sysdeps/s390/s390-32/__longjmp.c and sysdeps/s390/s390-64/__longjmp.c
are special: These are C sources, but most of the implementation is
in assembler, so the PTR_DEMANGLE macro has to be undefined in some
cases, to match the assembler style.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-10-18 17:04:10 +02:00
Florian Weimer
88f4b6929c Introduce <pointer_guard.h>, extracted from <sysdep.h>
This allows us to define a generic no-op version of PTR_MANGLE and
PTR_DEMANGLE.  In the future, we can use PTR_MANGLE and PTR_DEMANGLE
unconditionally in C sources, avoiding an unintended loss of hardening
due to missing include files or unlucky header inclusion ordering.

In i386 and x86_64, we can avoid a <tls.h> dependency in the C
code by using the computed constant from <tcb-offsets.h>.  <sysdep.h>
no longer includes these definitions, so there is no cyclic dependency
anymore when computing the <tcb-offsets.h> constants.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-10-18 17:03:55 +02:00
Wilco Dijkstra
22f4ab2d20 Use atomic_exchange_release/acquire
Rename atomic_exchange_rel/acq to use atomic_exchange_release/acquire
since these map to the standard C11 atomic builtins.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-09-26 16:58:08 +01:00
Alistair Francis
2e81493fa6 riscv: Remove RV32 floating point functions
We don't need RV32 specific floating point functions, instead make them
generic for RISC-V.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-09-21 14:37:43 -04:00
Alistair Francis
73e9fe43ac riscv: Consolidate the libm-test-ulps
Both RV32 and RV64 should have the same libm-test-ulps, so consolidate
them into a single file.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-09-21 14:37:13 -04:00
Darius Rad
7c5db7931f riscv: Update rv64 libm test ulps
Generated on a Microsemi Polarfire Icicle Kit running Linux version
5.15.32.  Same ULPs were also produced on QEMU 5.2.0 running Linux
5.18.0.
2022-07-27 10:50:20 -03:00
Darius Rad
5b6d8a650d riscv: Update nofpu libm test ulps 2022-07-27 10:50:10 -03:00
Kito Cheng
c22d2021a9
riscv: Use memcpy to handle unaligned access when fixing R_RISCV_RELATIVE
Although RISC-V Linux will enable the unaligned memory access handler by
default, that is quite expensive in general, using memcpy will be much cheaper
- just break down that into several load/store byte instructions.

ARM and MIPS has similar issue:

ARM: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51456
MIPS: https://gcc.gnu.org/legacy-ml/gcc-help/2005-07/msg00325.html

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-06-30 08:04:52 -07:00
Kito Cheng
58fc66a91c
riscv: Use elf_machine_rela_relative to handle R_RISCV_RELATIVE
Minor clean-up, we need to change this part in following patch, clean this up
to prevent we duplicated the change twice.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-06-23 21:07:19 -07:00
Fangrui Song
57919813e7 riscv: Change the relocations handled for RTLD_BOOTSTRAP
The RTLD_BOOTSTRAP branch is used to relocate ld.so itself.  It only
needs to handle RELATIVE, GLOB_DAT, and the symbolic relocation type
(R_RISCV_{32,64}).  NONE and IRELATIVE can be removed.

The code relies on ld.so having DT_RELACOUNT so that the RTLD_BOOTSTRAP
branch does not need handle RELATIVE.  Drop this minor size
optimization for clarity.

Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-06-15 18:42:03 -07:00
Adhemerval Zanella
d62123c1ed riscv: Remove _dl_skip_args usage
Since ad43cac44a the generic code already shuffles the argv/envp/auxv
on the stack to remove the ld.so own arguments and thus _dl_skip_args
is always 0.   So there is no need to adjust the argc or argv.

Checked with qemu-user that arguments are correctly passed on both
constructors and main program.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
2022-05-30 16:33:22 -03:00
Maciej W. Rozycki
7b1cfba79e RISC-V: Use an autoconf template to produce `preconfigure'
Avoid fiddling with autoconf internals and use AC_DEFINE_UNQUOTED to
define macros in the configuration headers rather than handcoding an
equivalent shell sequence with the use of the `as_echo' undocumented
variable.

Switch to using AC_MSG_ERROR rather than `echo' and `exit' directly for
error handling.  Owing to the lack of any kind of error annotation it
makes it difficult to spot the message in the flood in a parallel build
and neither it is logged in `config.log'.

Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-05-13 17:07:23 +01:00
Fangrui Song
098a657fe4 elf: Replace PI_STATIC_AND_HIDDEN with opposite HIDDEN_VAR_NEEDS_DYNAMIC_RELOC
PI_STATIC_AND_HIDDEN indicates whether accesses to internal linkage
variables and hidden visibility variables in a shared object (ld.so)
need dynamic relocations (usually R_*_RELATIVE). PI (position
independent) in the macro name is a misnomer: a code sequence using GOT
is typically position-independent as well, but using dynamic relocations
does not meet the requirement.

Not defining PI_STATIC_AND_HIDDEN is legacy and we expect that all new
ports will define PI_STATIC_AND_HIDDEN. Current ports defining
PI_STATIC_AND_HIDDEN are more than the opposite. Change the configure
default.

No functional change.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-04-26 09:26:22 -07:00
Tom Coldrick
d2265570a7 manual: Avoid name collision in libm ULP table [BZ #28956]
The 32-bit and 64-bit variants of RISC-V share the same name - "RISC-V"
- when generating the libm error table for the info pages. This
collision, and the way how the table is generated, mean that the values
in the final table for "RISC-V" may be either for the 32- or 64-bit
variant, with no indication as to which.

As an additional side-effect, this makes the build non-reproducible, as
the error table generated is dependent upon the host filesystem
implementation.

To solve this issue, the libm-test-ulps-name files for both variants
have been modified to include their word size, so as to remove the
collision and provide more accurate information in the table.

An alternative proposed was to merge the two variants' ULP values into a
single file, but this would mean that information about error values is
lost, as the two variants are not identical. Some differences are
considerable, notably the values for the exp() function are large.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
2022-04-11 11:46:10 -04:00
Fangrui Song
3ee318c923 Remove -z combreloc and HAVE_Z_COMBRELOC
-z combreloc has been the default regadless of the architecture since
binutils commit f4d733664aabd7bd78c82895e030ec9779a92809 (2002). The
configure check added in commit fdde83499a (2001) has long been
unneeded.

We can therefore treat HAVE_Z_COMBRELOC as always 1 and delete dead code
paths in dl-machine.h files (many were copied from commit a711b01d34
and ee0cb67ec2).

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2022-04-04 17:19:07 -07:00
Paul Eggert
581c785bf3 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 7061 files FOO.

I then removed trailing white space from math/tgmath.h,
support/tst-support-open-dev-null-range.c, and
sysdeps/x86_64/multiarch/strlen-vec.S, to work around the following
obscure pre-commit check failure diagnostics from Savannah.  I don't
know why I run into these diagnostics whereas others evidently do not.

remote: *** 912-#endif
remote: *** 913:
remote: *** 914-
remote: *** error: lines with trailing whitespace found
...
remote: *** error: sysdeps/unix/sysv/linux/statx_cp.c: trailing lines
2022-01-01 11:40:24 -08:00
Adhemerval Zanella
83b8d5027d malloc: Remove memusage.h
And use machine-sp.h instead.  The Linux implementation is based on
already provided CURRENT_STACK_FRAME (used on nptl code) and
STACK_GROWS_UPWARD is replaced with _STACK_GROWS_UP.
2021-12-28 14:57:57 -03:00
Adhemerval Zanella
691d9ae9e6 Remove ununsed tcb-offset
Some architectures do not use the auto-generated tcb-offsets.h.
2021-12-17 17:47:29 -03:00
Aurelien Jarno
225da459ce riscv: align stack before calling _dl_init [BZ #28703]
Align the stack pointer to 128 bits during the call to _dl_init() as
specified by the RISC-V ABI [1]. This fixes the elf/tst-align2 test.

Fixes bug 28703.

[1] https://github.com/riscv-non-isa/riscv-elf-psabi-doc
2021-12-17 20:29:34 +01:00
Florian Weimer
627f5ede70 Remove TLS_TCB_ALIGN and TLS_INIT_TCB_ALIGN
TLS_INIT_TCB_ALIGN is not actually used.  TLS_TCB_ALIGN was likely
introduced to support a configuration where the thread pointer
has not the same alignment as THREAD_SELF.  Only ia64 seems to use
that, but for the stack/pointer guard, not for storing tcbhead_t.
Some ports use TLS_TCB_OFFSET and TLS_PRE_TCB_SIZE to shift
the thread pointer, potentially landing in a different residue class
modulo the alignment, but the changes should not impact that.

In general, given that TLS variables have their own alignment
requirements, having different alignment for the (unshifted) thread
pointer and struct pthread would potentially result in dynamic
offsets, leading to more complexity.

hppa had different values before: __alignof__ (tcbhead_t), which
seems to be 4, and __alignof__ (struct pthread), which was 8
(old default) and is now 32.  However, it defines THREAD_SELF as:

/* Return the thread descriptor for the current thread.  */
# define THREAD_SELF \
  ({ struct pthread *__self;			\
	__self = __get_cr27();			\
	__self - 1;				\
   })

So the thread pointer points after struct pthread (hence __self - 1),
and they have to have the same alignment on hppa as well.

Similarly, on ia64, the definitions were different.  We have:

# define TLS_PRE_TCB_SIZE \
  (sizeof (struct pthread)						\
   + (PTHREAD_STRUCT_END_PADDING < 2 * sizeof (uintptr_t)		\
      ? ((2 * sizeof (uintptr_t) + __alignof__ (struct pthread) - 1)	\
	 & ~(__alignof__ (struct pthread) - 1))				\
      : 0))
# define THREAD_SELF \
  ((struct pthread *) ((char *) __thread_self - TLS_PRE_TCB_SIZE))

And TLS_PRE_TCB_SIZE is a multiple of the struct pthread alignment
(confirmed by the new _Static_assert in sysdeps/ia64/libc-tls.c).

On m68k, we have a larger gap between tcbhead_t and struct pthread.
But as far as I can tell, the port is fine with that.  The definition
of TCB_OFFSET is sufficient to handle the shifted TCB scenario.

This fixes commit 23c77f6018
("nptl: Increase default TCB alignment to 32").

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-12-09 23:47:49 +01:00
Florian Weimer
ce2248ab91 nptl: Introduce <tcb-access.h> for THREAD_* accessors
These are common between most architectures.  Only the x86 targets
are outliers.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2021-12-09 09:49:32 +01:00
Florian Weimer
23c77f6018 nptl: Increase default TCB alignment to 32
rseq support will use a 32-byte aligned field in struct pthread,
so the whole struct needs to have at least that alignment.

nptl/tst-tls3mod.c uses TCB_ALIGNMENT, therefore include <descr.h>
to obtain the fallback definition.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
2021-12-03 20:43:31 +01:00
Adhemerval Zanella
09f214528c riscv: Build with -mno-relax if linker does not support R_RISCV_ALIGN
It allows build both glibc and tests with lld (Since lld does not
support R_RISCV_ALIGN linker relaxation).

Checked with a build for riscv32-linux-gnu-rv32imafdc-ilp32d and
riscv64-linux-gnu-rv64imafdc-lp64d.

Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Fangrui Song <maskray@google.com>
2021-11-03 09:25:06 -03:00
Fangrui Song
6838920383 riscv: Fix incorrect jal with HIDDEN_JUMPTARGET
A non-local STV_DEFAULT defined symbol is by default preemptible in a
shared object. j/jal cannot target a preemptible symbol. On other
architectures, such a jump instruction either causes PLT [BZ #18822], or
if short-ranged, sometimes rejected by the linker (but not by GNU ld's
riscv port [ld PR/28509]).

Use HIDDEN_JUMPTARGET to target a non-preemptible symbol instead.

With this patch, ld.so and libc.so can be linked with LLD if source
files are compiled/assembled with -mno-relax/-Wa,-mno-relax.

Acked-by: Palmer Dabbelt <palmer@dabbelt.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-10-28 11:39:49 -07:00
H.J. Lu
2ec99d8c42 ld.so: Initialize bootstrap_map.l_ld_readonly [BZ #28340]
1. Define DL_RO_DYN_SECTION to initalize bootstrap_map.l_ld_readonly
before calling elf_get_dynamic_info to get dynamic info in bootstrap_map,
2. Define a single

static inline bool
dl_relocate_ld (const struct link_map *l)
{
  /* Don't relocate dynamic section if it is readonly  */
  return !(l->l_ld_readonly || DL_RO_DYN_SECTION);
}

This updates BZ #28340 fix.
2021-10-19 06:40:38 -07:00
Adhemerval Zanella
d6d89608ac elf: Fix dynamic-link.h usage on rtld.c
The 4af6982e4c fix does not fully handle RTLD_BOOTSTRAP usage on
rtld.c due two issues:

  1. RTLD_BOOTSTRAP is also used on dl-machine.h on various
     architectures and it changes the semantics of various machine
     relocation functions.

  2. The elf_get_dynamic_info() change was done sideways, previously
     to 490e6c62aa get-dynamic-info.h was included by the first
     dynamic-link.h include *without* RTLD_BOOTSTRAP being defined.
     It means that the code within elf_get_dynamic_info() that uses
     RTLD_BOOTSTRAP is in fact unused.

To fix 1. this patch now includes dynamic-link.h only once with
RTLD_BOOTSTRAP defined.  The ELF_DYNAMIC_RELOCATE call will now have
the relocation fnctions with the expected semantics for the loader.

And to fix 2. part of 4af6982e4c is reverted (the check argument
elf_get_dynamic_info() is not required) and the RTLD_BOOTSTRAP
pieces are removed.

To reorganize the includes the static TLS definition is moved to
its own header to avoid a circular dependency (it is defined on
dynamic-link.h and dl-machine.h requires it at same time other
dynamic-link.h definition requires dl-machine.h defitions).

Also ELF_MACHINE_NO_REL, ELF_MACHINE_NO_RELA, and ELF_MACHINE_PLT_REL
are moved to its own header.  Only ancient ABIs need special values
(arm, i386, and mips), so a generic one is used as default.

The powerpc Elf64_FuncDesc is also moved to its own header, since
csu code required its definition (which would require either include
elf/ folder or add a full path with elf/).

Checked on x86_64, i686, aarch64, armhf, powerpc64, powerpc32,
and powerpc64le.

Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
2021-10-14 14:52:07 -03:00
Fangrui Song
490e6c62aa elf: Avoid nested functions in the loader [BZ #27220]
dynamic-link.h is included more than once in some elf/ files (rtld.c,
dl-conflict.c, dl-reloc.c, dl-reloc-static-pie.c) and uses GCC nested
functions. This harms readability and the nested functions usage
is the biggest obstacle prevents Clang build (Clang doesn't support GCC
nested functions).

The key idea for unnesting is to add extra parameters (struct link_map
*and struct r_scope_elm *[]) to RESOLVE_MAP,
ELF_MACHINE_BEFORE_RTLD_RELOC, ELF_DYNAMIC_RELOCATE, elf_machine_rel[a],
elf_machine_lazy_rel, and elf_machine_runtime_setup. (This is inspired
by Stan Shebs' ppc64/x86-64 implementation in the
google/grte/v5-2.27/master which uses mixed extra parameters and static
variables.)

Future simplification:
* If mips elf_machine_runtime_setup no longer needs RESOLVE_GOTSYM,
  elf_machine_runtime_setup can drop the `scope` parameter.
* If TLSDESC no longer need to be in elf_machine_lazy_rel,
  elf_machine_lazy_rel can drop the `scope` parameter.

Tested on aarch64, i386, x86-64, powerpc64le, powerpc64, powerpc32,
sparc64, sparcv9, s390x, s390, hppa, ia64, armhf, alpha, and mips64.
In addition, tested build-many-glibcs.py with {arc,csky,microblaze,nios2}-linux-gnu
and riscv64-linux-gnu-rv64imafdc-lp64d.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
2021-10-07 11:55:02 -07:00
Joseph Myers
b3f27d8150 Add narrowing fma functions
This patch adds the narrowing fused multiply-add functions from TS
18661-1 / TS 18661-3 / C2X to glibc's libm: ffma, ffmal, dfmal,
f32fmaf64, f32fmaf32x, f32xfmaf64 for all configurations; f32fmaf64x,
f32fmaf128, f64fmaf64x, f64fmaf128, f32xfmaf64x, f32xfmaf128,
f64xfmaf128 for configurations with _Float64x and _Float128;
__f32fmaieee128 and __f64fmaieee128 aliases in the powerpc64le case
(for calls to ffmal and dfmal when long double is IEEE binary128).
Corresponding tgmath.h macro support is also added.

The changes are mostly similar to those for the other narrowing
functions previously added, especially that for sqrt, so the
description of those generally applies to this patch as well.  As with
sqrt, I reused the same test inputs in auto-libm-test-in as for
non-narrowing fma rather than adding extra or separate inputs for
narrowing fma.  The tests in libm-test-narrow-fma.inc also follow
those for non-narrowing fma.

The non-narrowing fma has a known bug (bug 6801) that it does not set
errno on errors (overflow, underflow, Inf * 0, Inf - Inf).  Rather
than fixing this or having narrowing fma check for errors when
non-narrowing does not (complicating the cases when narrowing fma can
otherwise be an alias for a non-narrowing function), this patch does
not attempt to check for errors from narrowing fma and set errno; the
CHECK_NARROW_FMA macro is still present, but as a placeholder that
does nothing, and this missing errno setting is considered to be
covered by the existing bug rather than needing a separate open bug.
missing-errno annotations are duly added to many of the
auto-libm-test-in test inputs for fma.

This completes adding all the new functions from TS 18661-1 to glibc,
so will be followed by corresponding stdc-predef.h changes to define
__STDC_IEC_60559_BFP__ and __STDC_IEC_60559_COMPLEX__, as the support
for TS 18661-1 will be at a similar level to that for C standard
floating-point facilities up to C11 (pragmas not implemented, but
library functions done).  (There are still further changes to be done
to implement changes to the types of fromfp functions from N2548.)

Tested as followed: natively with the full glibc testsuite for x86_64
(GCC 11, 7, 6) and x86 (GCC 11); with build-many-glibcs.py with GCC
11, 7 and 6; cross testing of math/ tests for powerpc64le, powerpc32
hard float, mips64 (all three ABIs, both hard and soft float).  The
different GCC versions are to cover the different cases in tgmath.h
and tgmath.h tests properly (GCC 6 has _Float* only as typedefs in
glibc headers, GCC 7 has proper _Float* support, GCC 8 adds
__builtin_tgmath).
2021-09-22 21:25:31 +00:00
H.J. Lu
b413280cfb ld.so: Replace DL_RO_DYN_SECTION with dl_relocate_ld [BZ #28340]
We can't relocate entries in dynamic section if it is readonly:

1. Add a l_ld_readonly field to struct link_map to indicate if dynamic
section is readonly and set it based on p_flags of PT_DYNAMIC segment.
2. Replace DL_RO_DYN_SECTION with dl_relocate_ld to decide if dynamic
section should be relocated.
3. Remove DL_RO_DYN_TEMP_CNT.
4. Don't use a static dynamic section to make readonly dynamic section
in vDSO writable.
5. Remove the temp argument from elf_get_dynamic_info.

This fixes BZ #28340.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
2021-09-22 11:12:43 -07:00