linux-user/signal.c: Create a common rewind_if_in_safe_syscall

All instances of rewind_if_in_safe_syscall are the same, differing only in how the instruction point is fetched from the ucontext and the size of the registers. Use host_signal_pc and new host_signal_set_pc interfaces to fetch the pointer to the PC and adjust if needed. Delete all the old copies of rewind_if_in_safe_syscall. Acked-by: Laurent Vivier <laurent@vivier.eu> Signed-off-by: Warner Losh <imp@bsdimp.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org> Message-Id: <20211113045603.60391-3-imp@bsdimp.com> [rth: include safe-syscall.h, simplify ifdefs] Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
qemu · Nov 23, 2021 · 0763788 · 0763788
1 parent c6cda6a
commit 0763788
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Showing 9 changed files with 15 additions and 143 deletions.
diff --git a/linux-user/host/aarch64/hostdep.h b/linux-user/host/aarch64/hostdep.h
@@ -15,24 +15,4 @@
 /* We have a safe-syscall.inc.S */
 #define HAVE_SAFE_SYSCALL
 
-#ifndef __ASSEMBLER__
-
-/* These are defined by the safe-syscall.inc.S file */
-extern char safe_syscall_start[];
-extern char safe_syscall_end[];
-
-/* Adjust the signal context to rewind out of safe-syscall if we're in it */
-static inline void rewind_if_in_safe_syscall(void *puc)
-{
-    ucontext_t *uc = puc;
-    __u64 *pcreg = &uc->uc_mcontext.pc;
-
-    if (*pcreg > (uintptr_t)safe_syscall_start
-        && *pcreg < (uintptr_t)safe_syscall_end) {
-        *pcreg = (uintptr_t)safe_syscall_start;
-    }
-}
-
-#endif /* __ASSEMBLER__ */
-
 #endif
diff --git a/linux-user/host/arm/hostdep.h b/linux-user/host/arm/hostdep.h
@@ -15,24 +15,4 @@
 /* We have a safe-syscall.inc.S */
 #define HAVE_SAFE_SYSCALL
 
-#ifndef __ASSEMBLER__
-
-/* These are defined by the safe-syscall.inc.S file */
-extern char safe_syscall_start[];
-extern char safe_syscall_end[];
-
-/* Adjust the signal context to rewind out of safe-syscall if we're in it */
-static inline void rewind_if_in_safe_syscall(void *puc)
-{
-    ucontext_t *uc = puc;
-    unsigned long *pcreg = &uc->uc_mcontext.arm_pc;
-
-    if (*pcreg > (uintptr_t)safe_syscall_start
-        && *pcreg < (uintptr_t)safe_syscall_end) {
-        *pcreg = (uintptr_t)safe_syscall_start;
-    }
-}
-
-#endif /* __ASSEMBLER__ */
-
 #endif
diff --git a/linux-user/host/i386/hostdep.h b/linux-user/host/i386/hostdep.h
@@ -15,24 +15,4 @@
 /* We have a safe-syscall.inc.S */
 #define HAVE_SAFE_SYSCALL
 
-#ifndef __ASSEMBLER__
-
-/* These are defined by the safe-syscall.inc.S file */
-extern char safe_syscall_start[];
-extern char safe_syscall_end[];
-
-/* Adjust the signal context to rewind out of safe-syscall if we're in it */
-static inline void rewind_if_in_safe_syscall(void *puc)
-{
-    ucontext_t *uc = puc;
-    greg_t *pcreg = &uc->uc_mcontext.gregs[REG_EIP];
-
-    if (*pcreg > (uintptr_t)safe_syscall_start
-        && *pcreg < (uintptr_t)safe_syscall_end) {
-        *pcreg = (uintptr_t)safe_syscall_start;
-    }
-}
-
-#endif /* __ASSEMBLER__ */
-
 #endif
diff --git a/linux-user/host/ppc64/hostdep.h b/linux-user/host/ppc64/hostdep.h
@@ -15,24 +15,4 @@
 /* We have a safe-syscall.inc.S */
 #define HAVE_SAFE_SYSCALL
 
-#ifndef __ASSEMBLER__
-
-/* These are defined by the safe-syscall.inc.S file */
-extern char safe_syscall_start[];
-extern char safe_syscall_end[];
-
-/* Adjust the signal context to rewind out of safe-syscall if we're in it */
-static inline void rewind_if_in_safe_syscall(void *puc)
-{
-    ucontext_t *uc = puc;
-    unsigned long *pcreg = &uc->uc_mcontext.gp_regs[PT_NIP];
-
-    if (*pcreg > (uintptr_t)safe_syscall_start
-        && *pcreg < (uintptr_t)safe_syscall_end) {
-        *pcreg = (uintptr_t)safe_syscall_start;
-    }
-}
-
-#endif /* __ASSEMBLER__ */
-
 #endif
diff --git a/linux-user/host/riscv/hostdep.h b/linux-user/host/riscv/hostdep.h
@@ -11,24 +11,4 @@
 /* We have a safe-syscall.inc.S */
 #define HAVE_SAFE_SYSCALL
 
-#ifndef __ASSEMBLER__
-
-/* These are defined by the safe-syscall.inc.S file */
-extern char safe_syscall_start[];
-extern char safe_syscall_end[];
-
-/* Adjust the signal context to rewind out of safe-syscall if we're in it */
-static inline void rewind_if_in_safe_syscall(void *puc)
-{
-    ucontext_t *uc = puc;
-    unsigned long *pcreg = &uc->uc_mcontext.__gregs[REG_PC];
-
-    if (*pcreg > (uintptr_t)safe_syscall_start
-        && *pcreg < (uintptr_t)safe_syscall_end) {
-        *pcreg = (uintptr_t)safe_syscall_start;
-    }
-}
-
-#endif /* __ASSEMBLER__ */
-
 #endif
diff --git a/linux-user/host/s390x/hostdep.h b/linux-user/host/s390x/hostdep.h
@@ -15,24 +15,4 @@
 /* We have a safe-syscall.inc.S */
 #define HAVE_SAFE_SYSCALL
 
-#ifndef __ASSEMBLER__
-
-/* These are defined by the safe-syscall.inc.S file */
-extern char safe_syscall_start[];
-extern char safe_syscall_end[];
-
-/* Adjust the signal context to rewind out of safe-syscall if we're in it */
-static inline void rewind_if_in_safe_syscall(void *puc)
-{
-    ucontext_t *uc = puc;
-    unsigned long *pcreg = &uc->uc_mcontext.psw.addr;
-
-    if (*pcreg > (uintptr_t)safe_syscall_start
-        && *pcreg < (uintptr_t)safe_syscall_end) {
-        *pcreg = (uintptr_t)safe_syscall_start;
-    }
-}
-
-#endif /* __ASSEMBLER__ */
-
 #endif
diff --git a/linux-user/host/x86_64/hostdep.h b/linux-user/host/x86_64/hostdep.h
@@ -15,24 +15,4 @@
 /* We have a safe-syscall.inc.S */
 #define HAVE_SAFE_SYSCALL
 
-#ifndef __ASSEMBLER__
-
-/* These are defined by the safe-syscall.inc.S file */
-extern char safe_syscall_start[];
-extern char safe_syscall_end[];
-
-/* Adjust the signal context to rewind out of safe-syscall if we're in it */
-static inline void rewind_if_in_safe_syscall(void *puc)
-{
-    ucontext_t *uc = puc;
-    greg_t *pcreg = &uc->uc_mcontext.gregs[REG_RIP];
-
-    if (*pcreg > (uintptr_t)safe_syscall_start
-        && *pcreg < (uintptr_t)safe_syscall_end) {
-        *pcreg = (uintptr_t)safe_syscall_start;
-    }
-}
-
-#endif /* __ASSEMBLER__ */
-
 #endif
diff --git a/linux-user/safe-syscall.h b/linux-user/safe-syscall.h
@@ -127,6 +127,9 @@
 #ifdef HAVE_SAFE_SYSCALL
 /* The core part of this function is implemented in assembly */
 extern long safe_syscall_base(int *pending, long number, ...);
+/* These are defined by the safe-syscall.inc.S file */
+extern char safe_syscall_start[];
+extern char safe_syscall_end[];
 
 #define safe_syscall(...)                                               \
     ({                                                                  \

diff --git a/linux-user/signal.c b/linux-user/signal.c
@@ -31,6 +31,7 @@
 #include "trace.h"
 #include "signal-common.h"
 #include "host-signal.h"
+#include "safe-syscall.h"
 
 static struct target_sigaction sigact_table[TARGET_NSIG];
 
@@ -793,12 +794,20 @@ int queue_signal(CPUArchState *env, int sig, int si_type,
     return 1; /* indicates that the signal was queued */
 }
 
-#ifndef HAVE_SAFE_SYSCALL
+
+/* Adjust the signal context to rewind out of safe-syscall if we're in it */
 static inline void rewind_if_in_safe_syscall(void *puc)
 {
-    /* Default version: never rewind */
-}
+#ifdef HAVE_SAFE_SYSCALL
+    ucontext_t *uc = (ucontext_t *)puc;
+    uintptr_t pcreg = host_signal_pc(uc);
+
+    if (pcreg > (uintptr_t)safe_syscall_start
+        && pcreg < (uintptr_t)safe_syscall_end) {
+        host_signal_set_pc(uc, (uintptr_t)safe_syscall_start);
+    }
 #endif
+}
 
 static void host_signal_handler(int host_sig, siginfo_t *info, void *puc)
 {