From: Nicholas Piggin <npiggin@gmail.com>
Date: Thu, 20 May 2021 14:00:36 +0000 (-0300)
Subject: powerpc: Fix handling of scv return error codes [BZ #27892]
X-Git-Tag: glibc-2.34~362
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7de36744ee1325f35d3fe0ca079dd33c40b12267;p=thirdparty%2Fglibc.git

powerpc: Fix handling of scv return error codes [BZ #27892]

When using scv for templated ASM syscalls, current code interprets any
negative return value as error, but the only valid error codes are in
the range -4095..-1 according to the ABI.

This commit also fixes 'signal.gen.test' strace test, where the issue
was first identified.

Reviewed-by: Matheus Castanho <msc@linux.ibm.com>
---

diff --git a/sysdeps/powerpc/powerpc64/sysdep.h b/sysdeps/powerpc/powerpc64/sysdep.h
index c57bb1c05d0..1ea4c3b9172 100644
--- a/sysdeps/powerpc/powerpc64/sysdep.h
+++ b/sysdeps/powerpc/powerpc64/sysdep.h
@@ -398,8 +398,9 @@ LT_LABELSUFFIX(name,_name_end): ; \
 #endif
 
 #define RET_SCV \
-    cmpdi r3,0; \
-    bgelr+; \
+    li r9,-4095; \
+    cmpld r3,r9; \
+    bltlr+; \
     neg r3,r3;
 
 #define RET_SC \