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Restore r31 setting in powerpc32 swapcontext
- From: Joseph Myers <joseph at codesourcery dot com>
- To: <libc-alpha at sourceware dot org>
- Cc: <adhemerval dot zanella at linaro dot org>, <tuliom at linux dot ibm dot com>
- Date: Tue, 30 Jul 2019 00:48:53 +0000
- Subject: Restore r31 setting in powerpc32 swapcontext
Commit ffe8a9a8318e1db225b22da8bc067408494bac5c, "powerpc: Remove
rt_sigreturn usage on context function", removed from powerpc32
swapcontext a setting of r31 that is relied upon in subsequent code.
I'm not sure why this didn't produce test failures in Adhemerval's
32-bit testing; in my (soft-float) testing in preparation for 2.30
release, I see several context-related failures
FAIL: stdlib/tst-makecontext2
FAIL: stdlib/tst-makecontext3
FAIL: stdlib/tst-setcontext
FAIL: stdlib/tst-setcontext2
FAIL: stdlib/tst-setcontext4
FAIL: stdlib/tst-setcontext7
FAIL: stdlib/tst-setcontext9
FAIL: stdlib/tst-swapcontext1
that did not appear in 2.29 testing. This patch restores the removed
register setting in question, and thus fixes those failures.
Tested for powerpc (soft-float).
2019-07-30 Joseph Myers <joseph@codesourcery.com>
* sysdeps/unix/sysv/linux/powerpc/powerpc32/swapcontext-common.S
(__CONTEXT_FUNC_NAME): Restore setting of r31.
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/swapcontext-common.S b/sysdeps/unix/sysv/linux/powerpc/powerpc32/swapcontext-common.S
index efebb10bba..6fa1ab7d6e 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/swapcontext-common.S
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/swapcontext-common.S
@@ -276,6 +276,9 @@ ENTRY(__CONTEXT_FUNC_NAME)
cmpwi r3,0
bne 3f /* L(error_exit) */
+ lwz r4,_FRAME_PARM_SAVE2(r1)
+ lwz r31,_UC_REGS_PTR(r4)
+
#ifdef __CONTEXT_ENABLE_FPRS
# ifdef __CONTEXT_ENABLE_VRS
--
Joseph S. Myers
joseph@codesourcery.com