[PULL 17/26] linux-user/openrisc: Implement setup_sigtramp

[Laurent Vivier <laurent@vivier.eu>]

From: Richard Henderson <richard.henderson@linaro.org>

Create and record the rt signal trampoline.

Reviewed-by: Stafford Horne <shorne@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210929130553.121567-18-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
 linux-user/openrisc/signal.c        | 22 ++++++++++++++--------
 linux-user/openrisc/target_signal.h |  2 ++
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/linux-user/openrisc/signal.c b/linux-user/openrisc/signal.c
index ca2532bf500f..be8b68784a20 100644
--- a/linux-user/openrisc/signal.c
+++ b/linux-user/openrisc/signal.c
@@ -38,7 +38,6 @@ typedef struct target_ucontext {
 typedef struct target_rt_sigframe {
     struct target_siginfo info;
     target_ucontext uc;
-    uint32_t retcode[4];  /* trampoline code */
 } target_rt_sigframe;
 
 static void restore_sigcontext(CPUOpenRISCState *env, target_sigcontext *sc)
@@ -116,14 +115,8 @@ void setup_rt_frame(int sig, struct target_sigaction *ka,
         __put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
     }
 
-    /* This is l.ori r11,r0,__NR_sigreturn; l.sys 1; l.nop; l.nop */
-    __put_user(0xa9600000 | TARGET_NR_rt_sigreturn, frame->retcode + 0);
-    __put_user(0x20000001, frame->retcode + 1);
-    __put_user(0x15000000, frame->retcode + 2);
-    __put_user(0x15000000, frame->retcode + 3);
-
     /* Set up registers for signal handler */
-    cpu_set_gpr(env, 9, frame_addr + offsetof(target_rt_sigframe, retcode));
+    cpu_set_gpr(env, 9, default_rt_sigreturn);
     cpu_set_gpr(env, 3, sig);
     cpu_set_gpr(env, 4, frame_addr + offsetof(target_rt_sigframe, info));
     cpu_set_gpr(env, 5, frame_addr + offsetof(target_rt_sigframe, uc));
@@ -169,3 +162,16 @@ long do_rt_sigreturn(CPUOpenRISCState *env)
     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);
+
+    /* This is l.ori r11,r0,__NR_sigreturn; l.sys 1 */
+    __put_user(0xa9600000 | TARGET_NR_rt_sigreturn, tramp + 0);
+    __put_user(0x20000001, tramp + 1);
+
+    default_rt_sigreturn = sigtramp_page;
+    unlock_user(tramp, sigtramp_page, 8);
+}
diff --git a/linux-user/openrisc/target_signal.h b/linux-user/openrisc/target_signal.h
index 8283eaf54419..077ec3d5e8d7 100644
--- a/linux-user/openrisc/target_signal.h
+++ b/linux-user/openrisc/target_signal.h
@@ -26,4 +26,6 @@ typedef struct target_sigaltstack {
 
 #include "../generic/signal.h"
 
+#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 1
+
 #endif /* OPENRISC_TARGET_SIGNAL_H */
-- 
2.31.1