mirror of git://sourceware.org/git/glibc.git
99 lines
4.1 KiB
C
99 lines
4.1 KiB
C
/* RSEQ_* accessors. i386 version.
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Copyright (C) 2002-2025 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#define __RSEQ_GETMEM(member) \
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({ __typeof (RSEQ_SELF()->member) __value; \
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if (sizeof (__value) == 1) \
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asm volatile ("movb %%gs:%P2(%3),%b0" \
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: "=q" (__value) \
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: "0" (0), "i" (offsetof (struct rseq_area, member)), \
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"r" (__rseq_offset)); \
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else if (sizeof (__value) == 4) \
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asm volatile ("movl %%gs:%P1(%2),%0" \
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: "=r" (__value) \
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: "i" (offsetof (struct rseq_area, member)), \
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"r" (__rseq_offset)); \
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else /* 8 */ \
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{ \
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asm volatile ("movl %%gs:%P1(%2),%%eax\n\t" \
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"movl %%gs:4+%P1(%2),%%edx" \
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: "=&A" (__value) \
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: "i" (offsetof (struct rseq_area, member)), \
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"r" (__rseq_offset)); \
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} \
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__value; })
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/* Read member of the RSEQ area directly. */
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#define RSEQ_GETMEM(member) \
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({ \
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_Static_assert (sizeof (RSEQ_SELF()->member) == 1 \
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|| sizeof (RSEQ_SELF()->member) == 4 \
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|| sizeof (RSEQ_SELF()->member) == 8, \
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"size of rseq data"); \
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__RSEQ_GETMEM(member); })
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/* Read member of the RSEQ area directly, with single-copy atomicity semantics.
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Static assert for types >= 64 bits since they can't be loaded atomically on
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x86-32. */
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#define RSEQ_GETMEM_ONCE(member) \
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({ \
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_Static_assert (sizeof (RSEQ_SELF()->member) == 1 \
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|| sizeof (RSEQ_SELF()->member) == 4, \
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"size of rseq data"); \
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__RSEQ_GETMEM(member); })
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#define __RSEQ_SETMEM(member, value) \
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({ \
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if (sizeof (RSEQ_SELF()->member) == 1) \
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asm volatile ("movb %b0,%%gs:%P1(%2)" : \
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: "iq" (value), \
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"i" (offsetof (struct rseq_area, member)), \
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"r" (__rseq_offset)); \
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else if (sizeof (RSEQ_SELF()->member) == 4) \
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asm volatile ("movl %0,%%gs:%P1(%2)" : \
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: "ir" (value), \
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"i" (offsetof (struct rseq_area, member)), \
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"r" (__rseq_offset)); \
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else /* 8 */ \
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{ \
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asm volatile ("movl %%eax,%%gs:%P1(%2)\n\t" \
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"movl %%edx,%%gs:4+%P1(%2)" : \
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: "A" ((uint64_t) cast_to_integer (value)), \
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"i" (offsetof (struct rseq_area, member)), \
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"r" (__rseq_offset)); \
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}})
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/* Set member of the RSEQ area directly. */
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#define RSEQ_SETMEM(member, value) \
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({ \
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_Static_assert (sizeof (RSEQ_SELF()->member) == 1 \
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|| sizeof (RSEQ_SELF()->member) == 4 \
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|| sizeof (RSEQ_SELF()->member) == 8, \
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"size of rseq data"); \
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__RSEQ_SETMEM(member, value); })
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/* Set member of the RSEQ area directly, with single-copy atomicity semantics.
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Static assert for types >= 64 bits since they can't be stored atomically on
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x86-32. */
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#define RSEQ_SETMEM_ONCE(member, value) \
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({ \
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_Static_assert (sizeof (RSEQ_SELF()->member) == 1 \
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|| sizeof (RSEQ_SELF()->member) == 4, \
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"size of rseq data"); \
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__RSEQ_SETMEM(member, value); })
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