mirror of
https://sourceware.org/git/glibc.git
synced 2025-10-28 23:34:53 +03:00
84 lines
2.8 KiB
C
84 lines
2.8 KiB
C
/* Emulate AT_MINSIGSTKSZ. Linux/x86 version.
|
|
Copyright (C) 2020-2025 Free Software Foundation, Inc.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
/* Emulate AT_MINSIGSTKSZ with XSAVE. */
|
|
|
|
static inline void
|
|
dl_check_minsigstacksize (const struct cpu_features *cpu_features)
|
|
{
|
|
/* Return if AT_MINSIGSTKSZ is provide by kernel. */
|
|
if (GLRO(dl_minsigstacksize) != 0)
|
|
return;
|
|
|
|
if (cpu_features->basic.max_cpuid >= 0xd
|
|
&& CPU_FEATURES_CPU_P (cpu_features, OSXSAVE))
|
|
{
|
|
/* Emulate AT_MINSIGSTKSZ. In Linux kernel, the signal frame data
|
|
with XSAVE is composed of the following areas and laid out as:
|
|
------------------------------
|
|
| alignment padding |
|
|
------------------------------
|
|
| xsave buffer |
|
|
------------------------------
|
|
| fsave header (32-bit only) |
|
|
------------------------------
|
|
| siginfo + ucontext |
|
|
------------------------------
|
|
*/
|
|
|
|
unsigned int sigframe_size;
|
|
|
|
#ifdef __x86_64__
|
|
/* NB: sizeof(struct rt_sigframe) + 8-byte return address in Linux
|
|
kernel. */
|
|
sigframe_size = 440 + 8;
|
|
#else
|
|
/* NB: sizeof(struct sigframe_ia32) + sizeof(struct fregs_state)) +
|
|
4-byte return address + 3 * 4-byte arguments in Linux kernel. */
|
|
sigframe_size = 736 + 112 + 4 + 3 * 4;
|
|
#endif
|
|
|
|
/* Add 15 bytes to align the stack to 16 bytes. */
|
|
sigframe_size += 15;
|
|
|
|
/* Make the space before xsave buffer multiple of 16 bytes. */
|
|
sigframe_size = ALIGN_UP (sigframe_size, 16);
|
|
|
|
/* Add (64 - 16)-byte padding to align xsave buffer at 64 bytes. */
|
|
sigframe_size += 64 - 16;
|
|
|
|
unsigned int eax, ebx, ecx, edx;
|
|
__cpuid_count (0xd, 0, eax, ebx, ecx, edx);
|
|
|
|
/* Add the size of xsave buffer. */
|
|
sigframe_size += ebx;
|
|
|
|
/* Add the size of FP_XSTATE_MAGIC2. */
|
|
#define FP_XSTATE_MAGIC2 0x46505845U
|
|
sigframe_size += sizeof (FP_XSTATE_MAGIC2);
|
|
|
|
GLRO(dl_minsigstacksize) = sigframe_size;
|
|
}
|
|
else
|
|
{
|
|
/* NB: Default to a constant MINSIGSTKSZ. */
|
|
_Static_assert (__builtin_constant_p (MINSIGSTKSZ),
|
|
"MINSIGSTKSZ is constant");
|
|
GLRO(dl_minsigstacksize) = MINSIGSTKSZ;
|
|
}
|
|
}
|