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[PATCH v3 26/27] linux-user/xtensa: Implement setup_sigtramp
From: |
Richard Henderson |
Subject: |
[PATCH v3 26/27] linux-user/xtensa: Implement setup_sigtramp |
Date: |
Fri, 24 Sep 2021 12:59:25 -0400 |
Create and record the rt signal trampoline.
Use it when the guest does not use SA_RESTORER.
Reviewed-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
linux-user/xtensa/target_signal.h | 2 ++
linux-user/xtensa/signal.c | 56 ++++++++++++++++++++-----------
2 files changed, 38 insertions(+), 20 deletions(-)
diff --git a/linux-user/xtensa/target_signal.h
b/linux-user/xtensa/target_signal.h
index c60bf656f6..1c7ee73154 100644
--- a/linux-user/xtensa/target_signal.h
+++ b/linux-user/xtensa/target_signal.h
@@ -20,4 +20,6 @@ typedef struct target_sigaltstack {
#include "../generic/signal.h"
+#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 1
+
#endif
diff --git a/linux-user/xtensa/signal.c b/linux-user/xtensa/signal.c
index 7a3bfb92ca..81572a5fc7 100644
--- a/linux-user/xtensa/signal.c
+++ b/linux-user/xtensa/signal.c
@@ -128,6 +128,29 @@ static int setup_sigcontext(struct target_rt_sigframe
*frame,
return 1;
}
+static void install_sigtramp(uint8_t *tramp)
+{
+#ifdef TARGET_WORDS_BIGENDIAN
+ /* Generate instruction: MOVI a2, __NR_rt_sigreturn */
+ __put_user(0x22, &tramp[0]);
+ __put_user(0x0a, &tramp[1]);
+ __put_user(TARGET_NR_rt_sigreturn, &tramp[2]);
+ /* Generate instruction: SYSCALL */
+ __put_user(0x00, &tramp[3]);
+ __put_user(0x05, &tramp[4]);
+ __put_user(0x00, &tramp[5]);
+#else
+ /* Generate instruction: MOVI a2, __NR_rt_sigreturn */
+ __put_user(0x22, &tramp[0]);
+ __put_user(0xa0, &tramp[1]);
+ __put_user(TARGET_NR_rt_sigreturn, &tramp[2]);
+ /* Generate instruction: SYSCALL */
+ __put_user(0x00, &tramp[3]);
+ __put_user(0x50, &tramp[4]);
+ __put_user(0x00, &tramp[5]);
+#endif
+}
+
void setup_rt_frame(int sig, struct target_sigaction *ka,
target_siginfo_t *info,
target_sigset_t *set, CPUXtensaState *env)
@@ -164,26 +187,9 @@ void setup_rt_frame(int sig, struct target_sigaction *ka,
if (ka->sa_flags & TARGET_SA_RESTORER) {
ra = ka->sa_restorer;
} else {
- ra = frame_addr + offsetof(struct target_rt_sigframe, retcode);
-#ifdef TARGET_WORDS_BIGENDIAN
- /* Generate instruction: MOVI a2, __NR_rt_sigreturn */
- __put_user(0x22, &frame->retcode[0]);
- __put_user(0x0a, &frame->retcode[1]);
- __put_user(TARGET_NR_rt_sigreturn, &frame->retcode[2]);
- /* Generate instruction: SYSCALL */
- __put_user(0x00, &frame->retcode[3]);
- __put_user(0x05, &frame->retcode[4]);
- __put_user(0x00, &frame->retcode[5]);
-#else
- /* Generate instruction: MOVI a2, __NR_rt_sigreturn */
- __put_user(0x22, &frame->retcode[0]);
- __put_user(0xa0, &frame->retcode[1]);
- __put_user(TARGET_NR_rt_sigreturn, &frame->retcode[2]);
- /* Generate instruction: SYSCALL */
- __put_user(0x00, &frame->retcode[3]);
- __put_user(0x50, &frame->retcode[4]);
- __put_user(0x00, &frame->retcode[5]);
-#endif
+ /* Not used, but retain for ABI compatibility. */
+ install_sigtramp(frame->retcode);
+ ra = default_rt_sigreturn;
}
memset(env->regs, 0, sizeof(env->regs));
env->pc = ka->_sa_handler;
@@ -264,3 +270,13 @@ badframe:
force_sig(TARGET_SIGSEGV);
return -TARGET_QEMU_ESIGRETURN;
}
+
+void setup_sigtramp(abi_ulong sigtramp_page)
+{
+ uint8_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 6, 0);
+ assert(tramp != NULL);
+
+ default_rt_sigreturn = sigtramp_page;
+ install_sigtramp(tramp);
+ unlock_user(tramp, sigtramp_page, 6);
+}
--
2.25.1
- Re: [PATCH v3 20/27] linux-user/ppc: Simplify encode_trampoline, (continued)
- [PATCH v3 19/27] linux-user/openrisc: Implement setup_sigtramp, Richard Henderson, 2021/09/24
- [PATCH v3 21/27] linux-user/ppc: Implement setup_sigtramp, Richard Henderson, 2021/09/24
- [PATCH v3 27/27] linux-user: Remove default for TARGET_ARCH_HAS_SIGTRAMP_PAGE, Richard Henderson, 2021/09/24
- [PATCH v3 23/27] linux-user/s390x: Implement setup_sigtramp, Richard Henderson, 2021/09/24
- [PATCH v3 22/27] linux-user/riscv: Implement setup_sigtramp, Richard Henderson, 2021/09/24
- [PATCH v3 24/27] linux-user/sh4: Implement setup_sigtramp, Richard Henderson, 2021/09/24
- [PATCH v3 25/27] linux-user/sparc: Implement setup_sigtramp, Richard Henderson, 2021/09/24
- [PATCH v3 26/27] linux-user/xtensa: Implement setup_sigtramp,
Richard Henderson <=
- [PATCH v3 17/27] linux-user/nios2: Map a real kuser page, Richard Henderson, 2021/09/24