Compiler generates the following instruction sequence for GNU2 dynamic
TLS access:
leaq tls_var@TLSDESC(%rip), %rax
call *tls_var@TLSCALL(%rax)
or
leal tls_var@TLSDESC(%ebx), %eax
call *tls_var@TLSCALL(%eax)
CALL instruction is transparent to compiler which assumes all registers,
except for EFLAGS and RAX/EAX, are unchanged after CALL. When
_dl_tlsdesc_dynamic is called, it calls __tls_get_addr on the slow
path. __tls_get_addr is a normal function which doesn't preserve any
caller-saved registers. _dl_tlsdesc_dynamic saved and restored integer
caller-saved registers, but didn't preserve any other caller-saved
registers. Add _dl_tlsdesc_dynamic IFUNC functions for FNSAVE, FXSAVE,
XSAVE and XSAVEC to save and restore all caller-saved registers. This
fixes BZ #31372.
Add GLRO(dl_x86_64_runtime_resolve) with GLRO(dl_x86_tlsdesc_dynamic)
to optimize elf_machine_runtime_setup.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
(cherry picked from commit 0aac205a81)
Add APX registers to STATE_SAVE_MASK so that APX registers are saved in
ld.so trampoline. This fixes BZ #31371.
Also update STATE_SAVE_OFFSET and STATE_SAVE_MASK for i386 which will
be used by i386 _dl_tlsdesc_dynamic.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
(cherry picked from commit dfb05f8e70)
The following three changes have been added to provide initial Power11 support.
1. Add the directories to hold Power11 files.
2. Add support to select Power11 libraries based on AT_PLATFORM.
3. Let submachine=power11 be set automatically.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
Reviewed-by: Peter Bergner <bergner@linux.ibm.com>
(cherry picked from commit 1ea0511456)
This patch adds a new feature for powerpc. In order to get faster
access to the HWCAP3/HWCAP4 masks, similar to HWCAP/HWCAP2 (i.e. for
implementing __builtin_cpu_supports() in GCC) without the overhead of
reading them from the auxiliary vector, we now reserve space for them
in the TCB.
Suggested-by: Peter Bergner <bergner@linux.ibm.com>
Reviewed-by: Peter Bergner <bergner@linux.ibm.com>
(cherry picked from commit 3ab9b88e2a)
Originally, nptl/descr.h included <sys/rseq.h>, but we removed that
in commit 2c6b4b272e ("nptl:
Unconditionally use a 32-byte rseq area"). After that, it was
not ensured that the RSEQ_SIG macro was defined during sched_getcpu.c
compilation that provided a definition. This commit always checks
the rseq area for CPU number information before using the other
approaches.
This adds an unnecessary (but well-predictable) branch on
architectures which do not define RSEQ_SIG, but its cost is small
compared to the system call. Most architectures that have vDSO
acceleration for getcpu also have rseq support.
Fixes: 2c6b4b272e
Fixes: 1d350aa060
Reviewed-by: Arjun Shankar <arjun@redhat.com>
(cherry picked from commit 7a76f21867)
Starting with commit e57d8fc97b
"S390: Always use svc 0"
clone clobbers the call-saved register r7 in error case:
function or stack is NULL.
This patch restores the saved registers also in the error case.
Furthermore the existing test misc/tst-clone is extended to check
all error cases and that clone does not clobber registers in this
error case.
(cherry picked from commit 02782fd128)
For o32 we need to setup a minimal stack frame to allow cprestore
on __thread_start_clone3 (which instruct the linker to save the
gp for PIC). Also, there is no guarantee by kABI that $8 will be
preserved after syscall execution, so we need to save it on the
provided stack.
Checked on mipsel-linux-gnu.
Reported-by: Khem Raj <raj.khem@gmail.com>
Tested-by: Khem Raj <raj.khem@gmail.com>
(cherry picked from commit bbd248ac0d)
The commit 49d877a80b (arm: Remove
_dl_skip_args usage) removed the _SKIP_ARGS literal, which was
previously loader to r4 on loader _start. However, the cleanup did not
remove the following 'ldr r4, [sl, r4]' on _dl_start_user, used to check
to skip the arguments after ld self-relocations.
In my testing, the kernel initially set r4 to 0, which makes the
ldr instruction just read the _GLOBAL_OFFSET_TABLE_. However, since r4
is a callee-saved register; a different runtime might not zero
initialize it and thus trigger an invalid memory access.
Checked on arm-linux-gnu.
Reported-by: Adrian Ratiu <adrian.ratiu@collabora.com>
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
(cherry picked from commit 1e25112dc0)
Starting with commits
- 7ea510127e
string: Add libc_hidden_proto for strchrnul
- 22999b2f0f
string: Add libc_hidden_proto for memrchr
building glibc on s390x with --disable-multi-arch fails if only
the C-variant of strchrnul / memrchr is used. This is the case
if gcc uses -march < z13.
The build fails with:
../sysdeps/s390/strchrnul-c.c:28:49: error: ‘__strchrnul_c’ undeclared here (not in a function); did you mean ‘__strchrnul’?
28 | __hidden_ver1 (__strchrnul_c, __GI___strchrnul, __strchrnul_c);
With --disable-multi-arch, __strchrnul_c is not available as string/strchrnul.c
is just included without defining STRCHRNUL and thus we also don't have to create
the internal hidden symbol.
Tested-by: Andreas K. Hüttel <dilfridge@gentoo.org>
The small counts copy bytes comparsion should be unsigned (as the
memmove size argument). It fixes string/tst-memmove-overflow on
sparcv9, where the input size triggers an invalid code path.
Checked on sparc64-linux-gnu and sparcv9-linux-gnu.
Similar to sparc32 fix, remove the unwind information on the signal
return stubs. This fixes the regressions:
FAIL: nptl/tst-cancel24-static
FAIL: nptl/tst-cond8-static
FAIL: nptl/tst-mutex8-static
FAIL: nptl/tst-mutexpi8-static
FAIL: nptl/tst-mutexpi9
On sparc64-linux-gnu.
The FPU used by LEON does not preserve NaN payload. This change allows
the math/test-*-canonicalize tests to pass on LEON.
Signed-off-by: Daniel Cederman <cederman@gaisler.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Use the math_force_eval() macro to force the calculation to complete and
raise the exception.
With this change the math/test-fenv test pass.
Signed-off-by: Daniel Cederman <cederman@gaisler.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Conversions from a float to a long long on SPARC v8 uses a libgcc function
that may not raise the correct exceptions on overflow. It also may raise
spurious "inexact" exceptions on non overflow cases. This patch fixes the
problem in the same way as for RV32.
Signed-off-by: Daniel Cederman <cederman@gaisler.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The functions were previously written in C, but were not compiled
with unwind information. The ENTRY/END macros includes .cfi_startproc
and .cfi_endproc which adds unwind information. This caused the
tests cleanup-8 and cleanup-10 in the GCC testsuite to fail.
This patch adds a version of the ENTRY/END macros without the
CFI instructions that can be used instead.
sigaction registers a restorer address that is located two instructions
before the stub function. This patch adds a two instruction padding to
avoid that the unwinder accesses the unwind information from the function
that the linker has placed right before it in memory. This fixes an issue
with pthread_cancel that caused tst-mutex8-static (and other tests) to fail.
Signed-off-by: Daniel Cederman <cederman@gaisler.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
On LEON, if the stfsr instruction is immediately following a floating-point
operation instruction in a running program, with no other instruction in
between the two, the stfsr might behave as if the order was reversed
between the two instructions and the stfsr occurred before the
floating-point operation.
Add a nop instruction before the stfsr to prevent this from happening.
Signed-off-by: Daniel Cederman <cederman@gaisler.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Macros for using inline assembly to access the fp state register exists
in both fenv_private.h and in fpu_control.h. Let fenv_private.h use the
macros from fpu_control.h
Signed-off-by: Daniel Cederman <cederman@gaisler.com>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
This patch updates the kernel version in the tests tst-mman-consts.py,
tst-mount-consts.py and tst-pidfd-consts.py to 6.7. (There are no new
constants covered by these tests in 6.7 that need any other header
changes.)
Tested with build-many-glibcs.py.
Linux 6.7 adds the futex_requeue, futex_wait and futex_wake syscalls,
and enables map_shadow_stack for architectures previously missing it.
Update syscall-names.list and regenerate the arch-syscall.h headers
with build-many-glibcs.py update-syscalls.
Tested with build-many-glibcs.py.
Systemd execution environment configuration may prohibit changing a memory
mapping to become executable:
MemoryDenyWriteExecute=
Takes a boolean argument. If set, attempts to create memory mappings
that are writable and executable at the same time, or to change existing
memory mappings to become executable, or mapping shared memory segments
as executable, are prohibited.
When it is set, systemd service stops working if PLT rewrite is enabled.
Check if mprotect works before rewriting PLT. This fixes BZ #31230.
This also works with SELinux when deny_execmem is on.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Ffsll function randomly regress by ~20%, depending on how code gets
aligned in memory. Ffsll function code size is 17 bytes. Since default
function alignment is 16 bytes, it can load on 16, 32, 48 or 64 bytes
aligned memory. When ffsll function load at 16, 32 or 64 bytes aligned
memory, entire code fits in single 64 bytes cache line. When ffsll
function load at 48 bytes aligned memory, it splits in two cache line,
hence random regression.
Ffsll function size reduction from 17 bytes to 12 bytes ensures that it
will always fit in single 64 bytes cache line.
This patch fixes ffsll function random performance regression.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
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>
The 551101e824 change is incorrect for
alpha and sparc, since __NR_stat is defined by both kABI. Use
__NR_newfstat to check whether to fallback to __NR_fstat64 (similar
to what fstatat64 does).
Checked on sparc64-linux-gnu.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Remove the error handling wrapper from exp10. This is very similar to
the changes done to exp and exp2, except that we also need to handle
pow10 and pow10l.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
The __getrandom_nocancel function returns errors as negative values
instead of errno. This is inconsistent with other _nocancel functions
and it breaks "TEMP_FAILURE_RETRY (__getrandom_nocancel (p, n, 0))" in
__arc4random_buf. Use INLINE_SYSCALL_CALL instead of
INTERNAL_SYSCALL_CALL to fix this issue.
But __getrandom_nocancel has been avoiding from touching errno for a
reason, see BZ 29624. So add a __getrandom_nocancel_nostatus function
and use it in tcache_key_initialize.
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Signed-off-by: Andreas K. Hüttel <dilfridge@gentoo.org>
CET feature bits in TCB, which are Linux specific, are used to check if
CET features are active. Move CET feature check to Linux/x86 directory.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
1. Remove _dl_runtime_resolve_shstk and _dl_runtime_profile_shstk.
2. Move CET offsets from x86 cpu-features-offsets.sym to x86-64
features-offsets.sym.
3. Rename x86 cet-control.h to x86-64 feature-control.h since it is only
for x86-64 and also used for PLT rewrite.
4. Add x86-64 ldsodefs.h to include feature-control.h.
5. Change TUNABLE_CALLBACK (set_plt_rewrite) to x86-64 only.
6. Move x86 dl-procruntime.c to x86-64.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Move sysdeps/x86/libc-start.h to sysdeps/x86_64/libc-start.h and use
sysdeps/generic/libc-start.h for i386.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
CET is only support for x86_64, this patch reverts:
- faaee1f07e x86: Support shadow stack pointer in setjmp/longjmp.
- be9ccd27c0 i386: Add _CET_ENDBR to indirect jump targets in
add_n.S/sub_n.S
- c02695d776 x86/CET: Update vfork to prevent child return
- 5d844e1b72 i386: Enable CET support in ucontext functions
- 124bcde683 x86: Add _CET_ENDBR to functions in crti.S
- 562837c002 x86: Add _CET_ENDBR to functions in dl-tlsdesc.S
- f753fa7dea x86: Support IBT and SHSTK in Intel CET [BZ #21598]
- 825b58f3fb i386-mcount.S: Add _CET_ENDBR to _mcount and __fentry__
- 7e119cd582 i386: Use _CET_NOTRACK in i686/memcmp.S
- 177824e232 i386: Use _CET_NOTRACK in memcmp-sse4.S
- 0a899af097 i386: Use _CET_NOTRACK in memcpy-ssse3-rep.S
- 7fb613361c i386: Use _CET_NOTRACK in memcpy-ssse3.S
- 77a8ae0948 i386: Use _CET_NOTRACK in memset-sse2-rep.S
- 00e7b76a8f i386: Use _CET_NOTRACK in memset-sse2.S
- 90d15dc577 i386: Use _CET_NOTRACK in strcat-sse2.S
- f1574581c7 i386: Use _CET_NOTRACK in strcpy-sse2.S
- 4031d7484a i386/sub_n.S: Add a missing _CET_ENDBR to indirect jump
- target
-
Checked on i686-linux-gnu.
The CET is only supported for x86_64 and there is no plan to add
kernel support for i386. Move the Makefile rules and files from the
generic x86 folder to x86_64 one.
Checked on x86_64-linux-gnu and i686-linux-gnu.
PLT rewrite calculated displacement with
ElfW(Addr) disp = value - branch_start - JMP32_INSN_SIZE;
On x32, displacement from 0xf7fbe060 to 0x401030 was calculated as
unsigned int disp = 0x401030 - 0xf7fbe060 - 5;
with disp == 0x8442fcb and caused displacement overflow. The PLT entry
was changed to:
0xf7fbe060 <+0>: e9 cb 2f 44 08 jmp 0x401030
0xf7fbe065 <+5>: cc int3
0xf7fbe066 <+6>: cc int3
0xf7fbe067 <+7>: cc int3
0xf7fbe068 <+8>: cc int3
0xf7fbe069 <+9>: cc int3
0xf7fbe06a <+10>: cc int3
0xf7fbe06b <+11>: cc int3
0xf7fbe06c <+12>: cc int3
0xf7fbe06d <+13>: cc int3
0xf7fbe06e <+14>: cc int3
0xf7fbe06f <+15>: cc int3
x32 has 32-bit address range, but it doesn't wrap address around at 4GB,
JMP target was changed to 0x100401030 (0xf7fbe060LL + 0x8442fcbLL + 5),
which is above 4GB.
Always use uint64_t to calculate displacement. This fixes BZ #31218.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
Add ELF_DYNAMIC_AFTER_RELOC to allow target specific processing after
relocation.
For x86-64, add
#define DT_X86_64_PLT (DT_LOPROC + 0)
#define DT_X86_64_PLTSZ (DT_LOPROC + 1)
#define DT_X86_64_PLTENT (DT_LOPROC + 3)
1. DT_X86_64_PLT: The address of the procedure linkage table.
2. DT_X86_64_PLTSZ: The total size, in bytes, of the procedure linkage
table.
3. DT_X86_64_PLTENT: The size, in bytes, of a procedure linkage table
entry.
With the r_addend field of the R_X86_64_JUMP_SLOT relocation set to the
memory offset of the indirect branch instruction.
Define ELF_DYNAMIC_AFTER_RELOC for x86-64 to rewrite the PLT section
with direct branch after relocation when the lazy binding is disabled.
PLT rewrite is disabled by default since SELinux may disallow modifying
code pages and ld.so can't detect it in all cases. Use
$ export GLIBC_TUNABLES=glibc.cpu.plt_rewrite=1
to enable PLT rewrite with 32-bit direct jump at run-time or
$ export GLIBC_TUNABLES=glibc.cpu.plt_rewrite=2
to enable PLT rewrite with 32-bit direct jump and on APX processors with
64-bit absolute jump at run-time.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
These describe generic AArch64 CPU features, and are not tied to a
kernel-specific way of determining them. We can share them between
the Linux and Hurd AArch64 ports.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-ID: <20240103171502.1358371-13-bugaevc@gmail.com>
We fetch __vm_page_size as the very first RPC that we do, inside
__mach_init (). Propagate that to _dl_pagesize ASAP after that,
before any other initialization.
In dynamic builds, this is already done immediately after
__mach_init (), inside _dl_sysdep_start ().
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-ID: <20240103171502.1358371-12-bugaevc@gmail.com>
This is the case on both x86 architectures, but not on AArch64.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-ID: <20240103171502.1358371-11-bugaevc@gmail.com>
We already have the RETURN_TO macro for this exact use case, and it's already
used in the non-static code path. Use it here too.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-ID: <20240103171502.1358371-9-bugaevc@gmail.com>
Instead of relying on the stack frame layout to figure out where the stack
pointer was prior to the _hurd_stack_setup () call, just pass the pointer
as an argument explicitly. This is less brittle and much more portable.
Signed-off-by: Sergey Bugaev <bugaevc@gmail.com>
Message-ID: <20240103171502.1358371-8-bugaevc@gmail.com>
setcontext and swapcontext put a restore token on the old shadow stack
which is used to restore the target shadow stack when switching user
contexts. When longjmp from a user context, the target shadow stack
can be different from the current shadow stack and INCSSP can't be
used to restore the shadow stack pointer to the target shadow stack.
Update longjmp to search for a restore token. If found, use the token
to restore the shadow stack pointer before using INCSSP to pop the
shadow stack. Stop the token search and use INCSSP if the shadow stack
entry value is the same as the current shadow stack pointer.
It is a user error if there is a shadow stack switch without leaving a
restore token on the old shadow stack.
The only difference between __longjmp.S and __longjmp_chk.S is that
__longjmp_chk.S has a check for invalid longjmp usages. Merge
__longjmp.S and __longjmp_chk.S by adding the CHECK_INVALID_LONGJMP
macro.
Reviewed-by: Noah Goldstein <goldstein.w.n@gmail.com>
Since shadow stack is only supported for x86-64, ignore --enable-cet for
i386. Always setting $(enable-cet) for i386 to "no" to support
ifneq ($(enable-cet),no)
in x86 Makefiles. We can't use
ifeq ($(enable-cet),yes)
since $(enable-cet) can be "yes", "no" or "permissive".
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
