linux-user/aarch64: Add padding before __kernel_rt_sigreturn
Without this padding, an unwind through the signal handler
will pick up the unwind info for the preceding syscall.
This fixes gcc's 30_threads/thread/native_handle/cancel.cc.
Cc: qemu-stable@nongnu.org
Fixes: ee95fae075c6 ("linux-user/aarch64: Add vdso")
Resolves: https://linaro.atlassian.net/browse/GNU-974
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240202034427.504686-1-richard.henderson@linaro.org>
diff --git a/linux-user/aarch64/vdso-be.so b/linux-user/aarch64/vdso-be.so
index 6084f3d..808206a 100755
--- a/linux-user/aarch64/vdso-be.so
+++ b/linux-user/aarch64/vdso-be.so
Binary files differ
diff --git a/linux-user/aarch64/vdso-le.so b/linux-user/aarch64/vdso-le.so
index 947d534..941aaf2 100755
--- a/linux-user/aarch64/vdso-le.so
+++ b/linux-user/aarch64/vdso-le.so
Binary files differ
diff --git a/linux-user/aarch64/vdso.S b/linux-user/aarch64/vdso.S
index 34d3a9e..a0ac148 100644
--- a/linux-user/aarch64/vdso.S
+++ b/linux-user/aarch64/vdso.S
@@ -63,7 +63,11 @@
* For now, elide the unwind info for __kernel_rt_sigreturn and rely on
* the libgcc fallback routine as we have always done. This requires
* that the code sequence used be exact.
+ *
+ * Add a nop as a spacer to ensure that unwind does not pick up the
+ * unwind info from the preceding syscall.
*/
+ nop
__kernel_rt_sigreturn:
/* No BTI C insn here -- we arrive via RET. */
mov x8, #__NR_rt_sigreturn
