diff --git a/linux-user/i386/signal.c b/linux-user/i386/signal.c index 3b4b55fc0a..b38b5f108e 100644 --- a/linux-user/i386/signal.c +++ b/linux-user/i386/signal.c @@ -310,6 +310,22 @@ get_sigframe(struct target_sigaction *ka, CPUX86State *env, size_t frame_size) } #ifndef TARGET_X86_64 +static void install_sigtramp(void *tramp) +{ + /* This is popl %eax ; movl $syscall,%eax ; int $0x80 */ + __put_user(0xb858, (uint16_t *)(tramp + 0)); + __put_user(TARGET_NR_sigreturn, (int32_t *)(tramp + 2)); + __put_user(0x80cd, (uint16_t *)(tramp + 6)); +} + +static void install_rt_sigtramp(void *tramp) +{ + /* This is movl $syscall,%eax ; int $0x80 */ + __put_user(0xb8, (uint8_t *)(tramp + 0)); + __put_user(TARGET_NR_rt_sigreturn, (int32_t *)(tramp + 1)); + __put_user(0x80cd, (uint16_t *)(tramp + 5)); +} + /* compare linux/arch/i386/kernel/signal.c:setup_frame() */ void setup_frame(int sig, struct target_sigaction *ka, target_sigset_t *set, CPUX86State *env) @@ -338,16 +354,9 @@ void setup_frame(int sig, struct target_sigaction *ka, if (ka->sa_flags & TARGET_SA_RESTORER) { __put_user(ka->sa_restorer, &frame->pretcode); } else { - uint16_t val16; - abi_ulong retcode_addr; - retcode_addr = frame_addr + offsetof(struct sigframe, retcode); - __put_user(retcode_addr, &frame->pretcode); - /* This is popl %eax ; movl $,%eax ; int $0x80 */ - val16 = 0xb858; - __put_user(val16, (uint16_t *)(frame->retcode+0)); - __put_user(TARGET_NR_sigreturn, (int *)(frame->retcode+2)); - val16 = 0x80cd; - __put_user(val16, (uint16_t *)(frame->retcode+6)); + /* This is no longer used, but is retained for ABI compatibility. */ + install_sigtramp(frame->retcode); + __put_user(default_sigreturn, &frame->pretcode); } /* Set up registers for signal handler */ @@ -416,14 +425,9 @@ void setup_rt_frame(int sig, struct target_sigaction *ka, if (ka->sa_flags & TARGET_SA_RESTORER) { __put_user(ka->sa_restorer, &frame->pretcode); } else { - uint16_t val16; - addr = frame_addr + offsetof(struct rt_sigframe, retcode); - __put_user(addr, &frame->pretcode); - /* This is movl $,%eax ; int $0x80 */ - __put_user(0xb8, (char *)(frame->retcode+0)); - __put_user(TARGET_NR_rt_sigreturn, (int *)(frame->retcode+1)); - val16 = 0x80cd; - __put_user(val16, (uint16_t *)(frame->retcode+5)); + /* This is no longer used, but is retained for ABI compatibility. */ + install_rt_sigtramp(frame->retcode); + __put_user(default_rt_sigreturn, &frame->pretcode); } #else /* XXX: Would be slightly better to return -EFAULT here if test fails @@ -592,3 +596,19 @@ badframe: force_sig(TARGET_SIGSEGV); return -TARGET_QEMU_ESIGRETURN; } + +#ifndef TARGET_X86_64 +void setup_sigtramp(abi_ulong sigtramp_page) +{ + uint16_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 2 * 8, 0); + assert(tramp != NULL); + + default_sigreturn = sigtramp_page; + install_sigtramp(tramp); + + default_rt_sigreturn = sigtramp_page + 8; + install_rt_sigtramp(tramp + 8); + + unlock_user(tramp, sigtramp_page, 2 * 8); +} +#endif diff --git a/linux-user/i386/target_signal.h b/linux-user/i386/target_signal.h index 50361af874..64d09f2e75 100644 --- a/linux-user/i386/target_signal.h +++ b/linux-user/i386/target_signal.h @@ -22,4 +22,6 @@ typedef struct target_sigaltstack { #include "../generic/signal.h" #define TARGET_ARCH_HAS_SETUP_FRAME +#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 1 + #endif /* I386_TARGET_SIGNAL_H */ diff --git a/linux-user/x86_64/target_signal.h b/linux-user/x86_64/target_signal.h index 4ea74f20dd..4673c5a886 100644 --- a/linux-user/x86_64/target_signal.h +++ b/linux-user/x86_64/target_signal.h @@ -21,4 +21,7 @@ typedef struct target_sigaltstack { #include "../generic/signal.h" +/* For x86_64, use of SA_RESTORER is mandatory. */ +#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 0 + #endif /* X86_64_TARGET_SIGNAL_H */