diff mbox series

[PULL,08/26] linux-user/hexagon: Implement setup_sigtramp

Message ID 20211004074421.3141222-9-laurent@vivier.eu
State Accepted
Commit c8ef02b1acf0d78e909c6cbd38ed60ecc5ce52ff
Headers show
Series [PULL,01/26] linux-user: Add infrastructure for a signal trampoline page | expand

Commit Message

Laurent Vivier Oct. 4, 2021, 7:44 a.m. UTC 
From: Richard Henderson <richard.henderson@linaro.org>


Continue to initialize the words on the stack, as documented.
However, use the off-stack trampoline.

Reviewed-by: Taylor Simpson <tsimpson@quicinc.com>

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Message-Id: <20210929130553.121567-9-richard.henderson@linaro.org>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

---
 linux-user/hexagon/signal.c        | 19 +++++++++++++++++--
 linux-user/hexagon/target_signal.h |  2 ++
 2 files changed, 19 insertions(+), 2 deletions(-)

-- 
2.31.1
diff mbox series

Patch

diff --git a/linux-user/hexagon/signal.c b/linux-user/hexagon/signal.c
index c7f0bf6b9283..74e61739a0ab 100644
--- a/linux-user/hexagon/signal.c
+++ b/linux-user/hexagon/signal.c
@@ -162,6 +162,11 @@  void setup_rt_frame(int sig, struct target_sigaction *ka,
 
     setup_ucontext(&frame->uc, env, set);
     tswap_siginfo(&frame->info, info);
+    /*
+     * The on-stack signal trampoline is no longer executed;
+     * however, the libgcc signal frame unwinding code checks
+     * for the presence of these two numeric magic values.
+     */
     install_sigtramp(frame->tramp);
 
     env->gpr[HEX_REG_PC] = ka->_sa_handler;
@@ -171,8 +176,7 @@  void setup_rt_frame(int sig, struct target_sigaction *ka,
         frame_addr + offsetof(struct target_rt_sigframe, info);
     env->gpr[HEX_REG_R02] =
         frame_addr + offsetof(struct target_rt_sigframe, uc);
-    env->gpr[HEX_REG_LR] =
-        frame_addr + offsetof(struct target_rt_sigframe, tramp);
+    env->gpr[HEX_REG_LR] = default_rt_sigreturn;
 
     return;
 
@@ -271,3 +275,14 @@  badframe:
     force_sig(TARGET_SIGSEGV);
     return 0;
 }
+
+void setup_sigtramp(abi_ulong sigtramp_page)
+{
+    uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 4 * 2, 0);
+    assert(tramp != NULL);
+
+    default_rt_sigreturn = sigtramp_page;
+    install_sigtramp(tramp);
+
+    unlock_user(tramp, sigtramp_page, 4 * 2);
+}
diff --git a/linux-user/hexagon/target_signal.h b/linux-user/hexagon/target_signal.h
index 345cf1cbb843..9e0223d32225 100644
--- a/linux-user/hexagon/target_signal.h
+++ b/linux-user/hexagon/target_signal.h
@@ -31,4 +31,6 @@  typedef struct target_sigaltstack {
 
 #include "../generic/signal.h"
 
+#define TARGET_ARCH_HAS_SIGTRAMP_PAGE 1
+
 #endif /* TARGET_SIGNAL_H */