[PULL v2 58/58] linux-user/aarch64: Add padding before __kernel_rt_sigreturn

[Richard Henderson]

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>
---
 linux-user/aarch64/vdso-be.so | Bin 3216 -> 3224 bytes
 linux-user/aarch64/vdso-le.so | Bin 3216 -> 3224 bytes
 linux-user/aarch64/vdso.S     |   4 ++++
 3 files changed, 4 insertions(+)

diff --git a/linux-user/aarch64/vdso-be.so b/linux-user/aarch64/vdso-be.so
index 
6084f3d1a701316004894fcdd739c4e1e0463b68..808206ade824b09d786f6cc34f7cddf80b63130e
 100755
GIT binary patch
delta 121
zcmbOrIYV-SKI4pu2Kk&{7{Gw#%fuBAMC1c?^>~k}v|avdxNjSSLfftVb3bgJ!|2S&
z_-6A1CJrVZc?IUH8G;R$7#SF@Om<{a*v!K!&BXX-vIe^~TWO|cva$K*Om;sOMw`hy
ZxXl@VO#Z-a&zLdUfXALuXmSCM0s#EKC)of1

delta 116
zcmbOsIYDxQKI4Rm2Kk&H7{Gw#!^9O2L>8U?-5V_M@!kH(Sx4vJn|*ujLPgija~Pc&
z8DDIEz{J5c`3;N8W)W6tCdL<&4cM*OEF8_<v%@zRviq?xT1-B`ZO-^%@(*r%#)Qch
RJocPi5ThAdCO2?N002V6C;<Qf

diff --git a/linux-user/aarch64/vdso-le.so b/linux-user/aarch64/vdso-le.so
index 
947d534ec1899740edbd6921da6bc6e70e2ecd09..941aaf29931193300de1f62097867c282a7e0c74
 100755
GIT binary patch
delta 129
zcmbOrIYV-S2IGv0n)#exSQx<I%fyAxMZTVBQ(04AP_*V|Vxp|@=@;x8zb9;-!)U|E
z_-6A>CVnO!c?IUH8G;R$7#SF@Om<{a*v!K!!o>JyvLd?^n`3BUW_royOm=q`Mw`hS
dxy>1WOn%92&zLb;lgFM@hy!9z%j7~Xc>tTxDQW-!

delta 108
zcmbOsIYDxQ2IGW@n)#d`SQx<I!^DNpMK&+G&+g_}w9WI@dn@@euKVesZ-h6`VYFdn
ze6jf^6F<}BH!LcfMOa0c7+*}*WOrgKEO1Fl%G+GX?#{w!F?lDqIpc@PAGz%r6DAw-
M*fVlXF62=M06owo?*IS*

diff --git a/linux-user/aarch64/vdso.S b/linux-user/aarch64/vdso.S
index 34d3a9ebd2..a0ac1487b0 100644
--- a/linux-user/aarch64/vdso.S
+++ b/linux-user/aarch64/vdso.S
@@ -63,7 +63,11 @@ vdso_syscall __kernel_clock_getres, __NR_clock_getres
  * 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
-- 
2.34.1