tcg-aarch64: Properly detect SIGSEGV writes

Since the kernel doesn't pass any info on the reason for the fault,
disassemble the instruction to detect a store.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This commit is contained in:
Richard Henderson 2014-03-14 22:24:57 -04:00 committed by Richard Henderson
parent 851627352c
commit 661f7fa4b0

View File

@ -465,16 +465,29 @@ int cpu_signal_handler(int host_signum, void *pinfo,
#elif defined(__aarch64__)
int cpu_signal_handler(int host_signum, void *pinfo,
void *puc)
int cpu_signal_handler(int host_signum, void *pinfo, void *puc)
{
siginfo_t *info = pinfo;
struct ucontext *uc = puc;
uint64_t pc;
int is_write = 0; /* XXX how to determine? */
uintptr_t pc = uc->uc_mcontext.pc;
uint32_t insn = *(uint32_t *)pc;
bool is_write;
pc = uc->uc_mcontext.pc;
return handle_cpu_signal(pc, (uint64_t)info->si_addr,
/* XXX: need kernel patch to get write flag faster. */
is_write = ( (insn & 0xbfff0000) == 0x0c000000 /* C3.3.1 */
|| (insn & 0xbfe00000) == 0x0c800000 /* C3.3.2 */
|| (insn & 0xbfdf0000) == 0x0d000000 /* C3.3.3 */
|| (insn & 0xbfc00000) == 0x0d800000 /* C3.3.4 */
|| (insn & 0x3f400000) == 0x08000000 /* C3.3.6 */
|| (insn & 0x3bc00000) == 0x39000000 /* C3.3.13 */
|| (insn & 0x3fc00000) == 0x3d800000 /* ... 128bit */
/* Ingore bits 10, 11 & 21, controlling indexing. */
|| (insn & 0x3bc00000) == 0x38000000 /* C3.3.8-12 */
|| (insn & 0x3fe00000) == 0x3c800000 /* ... 128bit */
/* Ignore bits 23 & 24, controlling indexing. */
|| (insn & 0x3a400000) == 0x28000000); /* C3.3.7,14-16 */
return handle_cpu_signal(pc, (uintptr_t)info->si_addr,
is_write, &uc->uc_sigmask, puc);
}