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| author | Emilio G. Cota <cota@braap.org> | 2018-04-10 11:09:52 -0400 |
|---|---|---|
| committer | Richard Henderson <richard.henderson@linaro.org> | 2018-05-09 10:12:21 -0700 |
| commit | bfe7ad5be77a6a8925a7ab1628452c8942222102 (patch) | |
| tree | c7d530eeee4dee001046971a67e0a032ad7a4343 /target/arm/translate.c | |
| parent | 56371527f3f8d33be651046700d72489f4df505f (diff) | |
| download | qemu-bfe7ad5be77a6a8925a7ab1628452c8942222102.zip qemu-bfe7ad5be77a6a8925a7ab1628452c8942222102.tar.gz qemu-bfe7ad5be77a6a8925a7ab1628452c8942222102.tar.bz2 | |
target/arm: avoid integer overflow in next_page PC check
If the PC is in the last page of the address space, next_page_start
overflows to 0. Fix it.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Cc: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'target/arm/translate.c')
| -rw-r--r-- | target/arm/translate.c | 11 |
1 files changed, 5 insertions, 6 deletions
diff --git a/target/arm/translate.c b/target/arm/translate.c index ad20886..0f6629f 100644 --- a/target/arm/translate.c +++ b/target/arm/translate.c @@ -9930,7 +9930,7 @@ static bool thumb_insn_is_16bit(DisasContext *s, uint32_t insn) return false; } - if ((insn >> 11) == 0x1e && (s->pc < s->next_page_start - 3)) { + if ((insn >> 11) == 0x1e && s->pc - s->page_start < TARGET_PAGE_SIZE - 3) { /* 0b1111_0xxx_xxxx_xxxx : BL/BLX prefix, and the suffix * is not on the next page; we merge this into a 32-bit * insn. @@ -12301,8 +12301,7 @@ static int arm_tr_init_disas_context(DisasContextBase *dcbase, dc->is_ldex = false; dc->ss_same_el = false; /* Can't be true since EL_d must be AArch64 */ - dc->next_page_start = - (dc->base.pc_first & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE; + dc->page_start = dc->base.pc_first & TARGET_PAGE_MASK; /* If architectural single step active, limit to 1. */ if (is_singlestepping(dc)) { @@ -12312,7 +12311,7 @@ static int arm_tr_init_disas_context(DisasContextBase *dcbase, /* ARM is a fixed-length ISA. Bound the number of insns to execute to those left on the page. */ if (!dc->thumb) { - int bound = (dc->next_page_start - dc->base.pc_first) / 4; + int bound = -(dc->base.pc_first | TARGET_PAGE_MASK) / 4; max_insns = MIN(max_insns, bound); } @@ -12584,8 +12583,8 @@ static void thumb_tr_translate_insn(DisasContextBase *dcbase, CPUState *cpu) * but isn't very efficient). */ if (dc->base.is_jmp == DISAS_NEXT - && (dc->pc >= dc->next_page_start - || (dc->pc >= dc->next_page_start - 3 + && (dc->pc - dc->page_start >= TARGET_PAGE_SIZE + || (dc->pc - dc->page_start >= TARGET_PAGE_SIZE - 3 && insn_crosses_page(env, dc)))) { dc->base.is_jmp = DISAS_TOO_MANY; } |