diff options
| author | Richard Henderson <richard.henderson@linaro.org> | 2021-09-29 09:05:29 -0400 |
|---|---|---|
| committer | Laurent Vivier <laurent@vivier.eu> | 2021-10-01 12:03:48 +0200 |
| commit | c70887a38212fd8ba0141d61502a33cda0a38d2d (patch) | |
| tree | 9f9ea0b8a8675192a3af8db1ce51c3acd80fb0dc /linux-user | |
| parent | db2af69d6ba836a264878dbf2cf676d3c1fc46b4 (diff) | |
linux-user/aarch64: Implement setup_sigtramp
Create and record the rt signal trampoline.
Use it when the guest does not use SA_RESTORER.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210929130553.121567-3-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Diffstat (limited to 'linux-user')
| -rw-r--r-- | linux-user/aarch64/signal.c | 34 | ||||
| -rw-r--r-- | linux-user/aarch64/target_signal.h | 2 |
2 files changed, 23 insertions, 13 deletions
diff --git a/linux-user/aarch64/signal.c b/linux-user/aarch64/signal.c index 49025648cb..29c52db3f1 100644 --- a/linux-user/aarch64/signal.c +++ b/linux-user/aarch64/signal.c @@ -109,7 +109,6 @@ struct target_rt_sigframe { struct target_rt_frame_record { uint64_t fp; uint64_t lr; - uint32_t tramp[2]; }; static void target_setup_general_frame(struct target_rt_sigframe *sf, @@ -461,9 +460,9 @@ static void target_setup_frame(int usig, struct target_sigaction *ka, layout.total_size = MAX(layout.total_size, sizeof(struct target_rt_sigframe)); - /* Reserve space for the return code. On a real system this would - * be within the VDSO. So, despite the name this is not a "real" - * record within the frame. + /* + * Reserve space for the standard frame unwind pair: fp, lr. + * Despite the name this is not a "real" record within the frame. */ fr_ofs = layout.total_size; layout.total_size += sizeof(struct target_rt_frame_record); @@ -496,15 +495,7 @@ static void target_setup_frame(int usig, struct target_sigaction *ka, if (ka->sa_flags & TARGET_SA_RESTORER) { return_addr = ka->sa_restorer; } else { - /* - * mov x8,#__NR_rt_sigreturn; svc #0 - * Since these are instructions they need to be put as little-endian - * regardless of target default or current CPU endianness. - */ - __put_user_e(0xd2801168, &fr->tramp[0], le); - __put_user_e(0xd4000001, &fr->tramp[1], le); - return_addr = frame_addr + fr_ofs - + offsetof(struct target_rt_frame_record, tramp); + return_addr = default_rt_sigreturn; } env->xregs[0] = usig; env->xregs[29] = frame_addr + fr_ofs; @@ -577,3 +568,20 @@ long do_sigreturn(CPUARMState *env) { return do_rt_sigreturn(env); } + +void setup_sigtramp(abi_ulong sigtramp_page) +{ + uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 8, 0); + assert(tramp != NULL); + + /* + * mov x8,#__NR_rt_sigreturn; svc #0 + * Since these are instructions they need to be put as little-endian + * regardless of target default or current CPU endianness. + */ + __put_user_e(0xd2801168, &tramp[0], le); + __put_user_e(0xd4000001, &tramp[1], le); + + default_rt_sigreturn = sigtramp_page; + unlock_user(tramp, sigtramp_page, 8); +} diff --git a/linux-user/aarch64/target_signal.h b/linux-user/aarch64/target_signal.h index 18013e1b23..7580d99403 100644 --- a/linux-user/aarch64/target_signal.h +++ b/linux-user/aarch64/target_signal.h @@ -25,4 +25,6 @@ typedef struct target_sigaltstack { #define TARGET_SEGV_MTESERR 9 /* Synchronous ARM MTE exception */ #define TARGET_ARCH_HAS_SETUP_FRAME +#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 1 + #endif /* AARCH64_TARGET_SIGNAL_H */ |