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tcg/aarch64: Make direct jump patching thread-safe

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Ensure direct jump patching in AArch64 is atomic by using
atomic_read()/atomic_set() for code patching.

Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Message-Id: <1461341333-19646-9-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Sergey Fedorov 2016-04-22 19:08:50 +03:00 committed by Richard Henderson
parent 7d14e0e2d6
commit 9e26911295
1 changed files with 13 additions and 1 deletions
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14
tcg/aarch64/tcg-target.inc.c
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@ -73,6 +73,18 @@ static inline void reloc_pc26(tcg_insn_unit *code_ptr, tcg_insn_unit *target)
*code_ptr = deposit32(*code_ptr, 0, 26, offset);
}
static inline void reloc_pc26_atomic(tcg_insn_unit *code_ptr,
tcg_insn_unit *target)
{
ptrdiff_t offset = target - code_ptr;
tcg_insn_unit insn;
tcg_debug_assert(offset == sextract64(offset, 0, 26));
/* read instruction, mask away previous PC_REL26 parameter contents,
set the proper offset, then write back the instruction. */
insn = atomic_read(code_ptr);
atomic_set(code_ptr, deposit32(insn, 0, 26, offset));
}
static inline void reloc_pc19(tcg_insn_unit *code_ptr, tcg_insn_unit *target)
{
ptrdiff_t offset = target - code_ptr;
@ -835,7 +847,7 @@ void aarch64_tb_set_jmp_target(uintptr_t jmp_addr, uintptr_t addr)
tcg_insn_unit *code_ptr = (tcg_insn_unit *)jmp_addr;
tcg_insn_unit *target = (tcg_insn_unit *)addr;
reloc_pc26(code_ptr, target);
reloc_pc26_atomic(code_ptr, target);
flush_icache_range(jmp_addr, jmp_addr + 4);
}