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[PATCH v2 18/23] linux-user/riscv: Implement setup_sigtramp
From: |
Richard Henderson |
Subject: |
[PATCH v2 18/23] linux-user/riscv: Implement setup_sigtramp |
Date: |
Fri, 18 Jun 2021 12:29:46 -0700 |
Create and record the rt signal trampoline.
This fixes a bug wrt libgcc fallback unwinding. It expects
the stack pointer to point to the siginfo_t, whereas we had
inexplicably placed our private signal trampoline at the start
of the signal frame instead of the end. Now moot because we
have removed it from the stack frame entirely.
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
linux-user/riscv/target_signal.h | 2 ++
linux-user/riscv/signal.c | 22 +++++++++++++---------
2 files changed, 15 insertions(+), 9 deletions(-)
diff --git a/linux-user/riscv/target_signal.h b/linux-user/riscv/target_signal.h
index f113ba9a55..3e36fddc9d 100644
--- a/linux-user/riscv/target_signal.h
+++ b/linux-user/riscv/target_signal.h
@@ -15,4 +15,6 @@ typedef struct target_sigaltstack {
#include "../generic/signal.h"
+#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 1
+
#endif /* RISCV_TARGET_SIGNAL_H */
diff --git a/linux-user/riscv/signal.c b/linux-user/riscv/signal.c
index 9405c7fd9a..4086dfa5d5 100644
--- a/linux-user/riscv/signal.c
+++ b/linux-user/riscv/signal.c
@@ -46,7 +46,6 @@ struct target_ucontext {
};
struct target_rt_sigframe {
- uint32_t tramp[2]; /* not in kernel, which uses VDSO instead */
struct target_siginfo info;
struct target_ucontext uc;
};
@@ -104,12 +103,6 @@ static void setup_ucontext(struct target_ucontext *uc,
setup_sigcontext(&uc->uc_mcontext, env);
}
-static inline void install_sigtramp(uint32_t *tramp)
-{
- __put_user(0x08b00893, tramp + 0); /* li a7, 139 = __NR_rt_sigreturn */
- __put_user(0x00000073, tramp + 1); /* ecall */
-}
-
void setup_rt_frame(int sig, struct target_sigaction *ka,
target_siginfo_t *info,
target_sigset_t *set, CPURISCVState *env)
@@ -126,14 +119,13 @@ void setup_rt_frame(int sig, struct target_sigaction *ka,
setup_ucontext(&frame->uc, env, set);
tswap_siginfo(&frame->info, info);
- install_sigtramp(frame->tramp);
env->pc = ka->_sa_handler;
env->gpr[xSP] = frame_addr;
env->gpr[xA0] = sig;
env->gpr[xA1] = frame_addr + offsetof(struct target_rt_sigframe, info);
env->gpr[xA2] = frame_addr + offsetof(struct target_rt_sigframe, uc);
- env->gpr[xRA] = frame_addr + offsetof(struct target_rt_sigframe, tramp);
+ env->gpr[xRA] = default_rt_sigreturn;
return;
@@ -202,3 +194,15 @@ badframe:
force_sig(TARGET_SIGSEGV);
return 0;
}
+
+void setup_sigtramp(abi_ulong sigtramp_page)
+{
+ uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 8, 0);
+ assert(tramp != NULL);
+
+ __put_user(0x08b00893, tramp + 0); /* li a7, 139 = __NR_rt_sigreturn */
+ __put_user(0x00000073, tramp + 1); /* ecall */
+
+ default_rt_sigreturn = sigtramp_page;
+ unlock_user(tramp, sigtramp_page, 8);
+}
--
2.25.1
- [PATCH v2 10/23] linux-user/i386: Implement setup_sigtramp, (continued)
- [PATCH v2 10/23] linux-user/i386: Implement setup_sigtramp, Richard Henderson, 2021/06/18
- [PATCH v2 17/23] linux-user/ppc: Implement setup_sigtramp, Richard Henderson, 2021/06/18
- [PATCH v2 21/23] linux-user/sparc: Implement setup_sigtramp, Richard Henderson, 2021/06/18
- [PATCH v2 23/23] linux-user: Remove default for TARGET_ARCH_HAS_SIGTRAMP_PAGE, Richard Henderson, 2021/06/18
- [PATCH v2 19/23] linux-user/s390x: Implement setup_sigtramp, Richard Henderson, 2021/06/18
- [PATCH v2 15/23] linux-user/nios2: Document non-use of setup_sigtramp, Richard Henderson, 2021/06/18
- [PATCH v2 22/23] linux-user/xtensa: Implement setup_sigtramp, Richard Henderson, 2021/06/18
- [PATCH v2 18/23] linux-user/riscv: Implement setup_sigtramp,
Richard Henderson <=