bsd-user: Define TARGET_SIGSTACK_ALIGN and use it to round stack

Most (all?) targets require stacks to be properly aligned. Rather than a series of ifdefs in bsd-user/signal.h, instead use a manditory #define for all architectures. Signed-off-by: Warner Losh <[email protected]> Reviewed-by: Richard Henderson <[email protected]>
rnax · Jul 23, 2024 · 5fa2a10 · 5fa2a10
1 parent 5b6828d
commit 5fa2a10
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Showing 5 changed files with 9 additions and 8 deletions.
diff --git a/bsd-user/aarch64/target_arch_signal.h b/bsd-user/aarch64/target_arch_signal.h
@@ -77,4 +77,6 @@ struct target_sigframe {
     target_ucontext_t   sf_uc;  /* saved ucontext */
 };
 
+#define TARGET_SIGSTACK_ALIGN 16
+
 #endif /* TARGET_ARCH_SIGNAL_H */
diff --git a/bsd-user/arm/target_arch_signal.h b/bsd-user/arm/target_arch_signal.h
@@ -86,4 +86,6 @@ struct target_sigframe {
     target_mcontext_vfp_t sf_vfp; /* actual saved VFP context */
 };
 
+#define TARGET_SIGSTACK_ALIGN 8
+
 #endif /* TARGET_ARCH_SIGNAL_H */
diff --git a/bsd-user/i386/target_arch_signal.h b/bsd-user/i386/target_arch_signal.h
@@ -88,4 +88,6 @@ struct target_sigframe {
     uint32_t    __spare__[2];
 };
 
+#define TARGET_SIGSTACK_ALIGN 8
+
 #endif /* TARGET_ARCH_SIGNAL_H */
diff --git a/bsd-user/signal.c b/bsd-user/signal.c
@@ -728,14 +728,7 @@ static inline abi_ulong get_sigframe(struct target_sigaction *ka,
         sp = ts->sigaltstack_used.ss_sp + ts->sigaltstack_used.ss_size;
     }
 
-/* TODO: make this a target_arch function / define */
-#if defined(TARGET_ARM)
-    return (sp - frame_size) & ~7;
-#elif defined(TARGET_AARCH64)
-    return (sp - frame_size) & ~15;
-#else
-    return sp - frame_size;
-#endif
+    return ROUND_DOWN(sp - frame_size, TARGET_SIGSTACK_ALIGN);
 }
 
 /* compare to $M/$M/exec_machdep.c sendsig and sys/kern/kern_sig.c sigexit */

diff --git a/bsd-user/x86_64/target_arch_signal.h b/bsd-user/x86_64/target_arch_signal.h
@@ -97,4 +97,6 @@ struct target_sigframe {
     uint32_t    __spare__[2];
 };
 
+#define TARGET_SIGSTACK_ALIGN 16
+
 #endif /* TARGET_ARCH_SIGNAL_H */