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authorDaniel Cederman <cederman@gaisler.com>2024-01-16 09:31:41 +0100
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2024-01-18 08:27:44 -0300
commit7bd06985c0a143cdcba2762bfe020e53514a53de (patch)
treedf2364326971944c515146967cb637d482fb6b12
parent82a35070ec35616074343b8c4ffe6b1cff7e2793 (diff)
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sparc: Remove unwind information from signal return stubs [BZ #31244]
The functions were previously written in C, but were not compiled
with unwind information. The ENTRY/END macros includes .cfi_startproc
and .cfi_endproc which adds unwind information. This caused the
tests cleanup-8 and cleanup-10 in the GCC testsuite to fail.
This patch adds a version of the ENTRY/END macros without the
CFI instructions that can be used instead.

sigaction registers a restorer address that is located two instructions
before the stub function. This patch adds a two instruction padding to
avoid that the unwinder accesses the unwind information from the function
that the linker has placed right before it in memory. This fixes an issue
with pthread_cancel that caused tst-mutex8-static (and other tests) to fail.

Signed-off-by: Daniel Cederman <cederman@gaisler.com>
Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
-rw-r--r--sysdeps/sparc/sysdep.h9
-rw-r--r--sysdeps/unix/sysv/linux/sparc/sparc32/sigreturn_stub.S11
2 files changed, 16 insertions, 4 deletions
diff --git a/sysdeps/sparc/sysdep.h b/sysdeps/sparc/sysdep.h
index c00fe79fec..44a6952bff 100644
--- a/sysdeps/sparc/sysdep.h
+++ b/sysdeps/sparc/sysdep.h
@@ -76,6 +76,15 @@ C_LABEL(name)				\
 	cfi_endproc;			\
 	.size name, . - name
 
+#define ENTRY_NOCFI(name)			\
+	.align	4;			\
+	.global	C_SYMBOL_NAME(name);	\
+	.type	name, @function;	\
+C_LABEL(name)
+
+#define END_NOCFI(name)			\
+	.size name, . - name
+
 #undef LOC
 #define LOC(name)  .L##name
 
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/sigreturn_stub.S b/sysdeps/unix/sysv/linux/sparc/sparc32/sigreturn_stub.S
index 832223f8ce..21d36c50df 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/sigreturn_stub.S
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/sigreturn_stub.S
@@ -23,12 +23,15 @@
 
    [1] https://lkml.org/lkml/2016/5/27/465  */
 
-ENTRY (__rt_sigreturn_stub)
+	nop
+	nop
+
+ENTRY_NOCFI (__rt_sigreturn_stub)
 	mov	__NR_rt_sigreturn, %g1
 	ta	0x10
-END (__rt_sigreturn_stub)
+END_NOCFI (__rt_sigreturn_stub)
 
-ENTRY (__sigreturn_stub)
+ENTRY_NOCFI (__sigreturn_stub)
 	mov	__NR_sigreturn, %g1
 	ta	0x10
-END (__sigreturn_stub)
+END_NOCFI (__sigreturn_stub)