diff options
| author | Sergey Fedorov <serge.fdrv@gmail.com> | 2016-04-22 19:08:45 +0300 |
|---|---|---|
| committer | Richard Henderson <rth@twiddle.net> | 2016-05-12 14:06:40 -1000 |
| commit | 76442a939ef8fc062b35a890a824de203bb5bd5f (patch) | |
| tree | 3bfd290f9dd64655502b2ef9fc16c60172ed30dc | |
| parent | 6b587d3cda48e7ba26de8d30bf0d8a7063970715 (diff) | |
tci: Make direct jump patching thread-safe
Ensure direct jump patching in TCI is atomic by:
* naturally aligning a location of direct jump address;
* using atomic_read()/atomic_set() to load/store the address.
Signed-off-by: Sergey Fedorov <serge.fdrv@gmail.com>
Signed-off-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Message-Id: <1461341333-19646-4-git-send-email-sergey.fedorov@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
| -rw-r--r-- | include/exec/exec-all.h | 2 | ||||
| -rw-r--r-- | tcg/tci/tcg-target.inc.c | 2 | ||||
| -rw-r--r-- | tci.c | 5 |
3 files changed, 7 insertions, 2 deletions
diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index c75fb3ac25..d49befdba5 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -303,7 +303,7 @@ void tb_phys_invalidate(TranslationBlock *tb, tb_page_addr_t page_addr); static inline void tb_set_jmp_target1(uintptr_t jmp_addr, uintptr_t addr) { /* patch the branch destination */ - *(uint32_t *)jmp_addr = addr - (jmp_addr + 4); + atomic_set((int32_t *)jmp_addr, addr - (jmp_addr + 4)); /* no need to flush icache explicitly */ } #elif defined(_ARCH_PPC) diff --git a/tcg/tci/tcg-target.inc.c b/tcg/tci/tcg-target.inc.c index e2fc52a167..85eeb5de24 100644 --- a/tcg/tci/tcg-target.inc.c +++ b/tcg/tci/tcg-target.inc.c @@ -556,6 +556,8 @@ static void tcg_out_op(TCGContext *s, TCGOpcode opc, const TCGArg *args, if (s->tb_jmp_offset) { /* Direct jump method. */ tcg_debug_assert(args[0] < ARRAY_SIZE(s->tb_jmp_offset)); + /* Align for atomic patching and thread safety */ + s->code_ptr = QEMU_ALIGN_PTR_UP(s->code_ptr, 4); s->tb_jmp_offset[args[0]] = tcg_current_code_size(s); tcg_out32(s, 0); } else { @@ -1089,7 +1089,10 @@ uintptr_t tcg_qemu_tb_exec(CPUArchState *env, uint8_t *tb_ptr) goto exit; break; case INDEX_op_goto_tb: - t0 = tci_read_i32(&tb_ptr); + /* Jump address is aligned */ + tb_ptr = QEMU_ALIGN_PTR_UP(tb_ptr, 4); + t0 = atomic_read((int32_t *)tb_ptr); + tb_ptr += sizeof(int32_t); tci_assert(tb_ptr == old_code_ptr + op_size); tb_ptr += (int32_t)t0; continue; |