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[PATCH 09/19] nptl: s390: Fix Race conditions in pthread cancellation (BZ#12683)
- From: Adhemerval Zanella <adhemerval dot zanella at linaro dot org>
- To: libc-alpha at sourceware dot org
- Cc: Adhemerval Zanella <adhemerval dot zanella at linaro dot com>
- Date: Mon, 11 Dec 2017 17:06:53 -0200
- Subject: [PATCH 09/19] nptl: s390: Fix Race conditions in pthread cancellation (BZ#12683)
- Authentication-results: sourceware.org; auth=none
- References: <1513019223-7603-1-git-send-email-adhemerval.zanella@linaro.org>
From: Adhemerval Zanella <adhemerval.zanella@linaro.com>
This patch adds the s390 modifications required for the BZ#12683 fix.
It basically adds the required ucontext_get_pc function.
The built cancelable syscall wrapper for s390 using GCC 7.2.1 and
default configuration flags shows the wrappers on expected corrected
places:
---
__GI___syscall_cancel_arch:
.LFB39:
.cfi_startproc
stm %r6,%r15,24(%r15)
.cfi_offset 6, -72
.cfi_offset 7, -68
.cfi_offset 8, -64
.cfi_offset 9, -60
.cfi_offset 10, -56
.cfi_offset 11, -52
.cfi_offset 12, -48
.cfi_offset 13, -44
.cfi_offset 14, -40
.cfi_offset 15, -36
ahi %r15,-96
.cfi_def_cfa_offset 192
.global __syscall_cancel_arch_start
.type __syscall_cancel_arch_start,@function
__syscall_cancel_arch_start:
l %r0,0(%r2)
tml %r0,4
jne .L5
lr %r1,%r3
lr %r2,%r4
lr %r3,%r5
lr %r4,%r6
l %r5,192(%r15)
l %r6,196(%r15)
l %r7,200(%r15)
svc 0
.global __syscall_cancel_arch_end
.type __syscall_cancel_arch_end,@function
__syscall_cancel_arch_end:
l %r4,152(%r15)
lm %r6,%r15,120(%r15)
.cfi_remember_state
.cfi_restore 15
.cfi_restore 14
.cfi_restore 13
.cfi_restore 12
.cfi_restore 11
.cfi_restore 10
.cfi_restore 9
.cfi_restore 8
.cfi_restore 7
.cfi_restore 6
.cfi_def_cfa_offset 96
br %r4
.L5:
.cfi_restore_state
brasl %r14,__syscall_do_cancel
.cfi_endproc
---
The s390x version also shows similar placement:
---
__GI___syscall_cancel_arch:
.cfi_startproc
stmg %r6,%r15,48(%r15)
.cfi_offset 6, -112
.cfi_offset 7, -104
.cfi_offset 8, -96
.cfi_offset 9, -88
.cfi_offset 10, -80
.cfi_offset 11, -72
.cfi_offset 12, -64
.cfi_offset 13, -56
.cfi_offset 14, -48
.cfi_offset 15, -40
aghi %r15,-160
.cfi_def_cfa_offset 320
.global __syscall_cancel_arch_start
.type __syscall_cancel_arch_start,@function
__syscall_cancel_arch_start:
l %r0,0(%r2)
tmll %r0,4
jne .L5
lgr %r1,%r3
lgr %r2,%r4
lgr %r3,%r5
lgr %r4,%r6
lg %r5,320(%r15)
lg %r6,328(%r15)
lg %r7,336(%r15)
svc 0
.global __syscall_cancel_arch_end
.type __syscall_cancel_arch_end,@function
__syscall_cancel_arch_end:
lg %r4,272(%r15)
lmg %r6,%r15,208(%r15)
.cfi_remember_state
.cfi_restore 15
.cfi_restore 14
.cfi_restore 13
.cfi_restore 12
.cfi_restore 11
.cfi_restore 10
.cfi_restore 9
.cfi_restore 8
.cfi_restore 7
.cfi_restore 6
.cfi_def_cfa_offset 160
br %r4
.L5:
.cfi_restore_state
brasl %r14,__syscall_do_cancel
.cfi_endproc
---
Checked with a s390-linux-gnu and s390x-linux-gnu build with
run-tests-built=no.
* sysdeps/unix/sysv/linux/s390/sigcontextinfo.h (ucontext_get_pc):
New function.
---
ChangeLog | 3 +++
sysdeps/unix/sysv/linux/s390/sigcontextinfo.h | 17 +++++++++++++++++
2 files changed, 20 insertions(+)
diff --git a/sysdeps/unix/sysv/linux/s390/sigcontextinfo.h b/sysdeps/unix/sysv/linux/s390/sigcontextinfo.h
index 90ead3f..676a8bd 100644
--- a/sysdeps/unix/sysv/linux/s390/sigcontextinfo.h
+++ b/sysdeps/unix/sysv/linux/s390/sigcontextinfo.h
@@ -16,7 +16,11 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
+#ifndef _SIGCONTEXTINFO_H
+#define _SIGCONTEXTINFO_H
+
#include <signal.h>
+#include <stdint.h>
#define SIGCONTEXT struct sigcontext *
#define SIGCONTEXT_EXTRA_ARGS
@@ -25,3 +29,16 @@
#define GET_STACK(ctx) ((void *)((ctx)->sregs->regs.gprs[15]))
#define CALL_SIGHANDLER(handler, signo, ctx) \
(handler)((signo), SIGCONTEXT_EXTRA_ARGS (ctx))
+
+static inline uintptr_t
+ucontext_get_pc (const ucontext_t *uc)
+{
+#ifdef __s390x__
+ return uc->uc_mcontext.psw.addr;
+#else
+ /* We have 31bit addresses, remove bit 0. */
+ return uc->uc_mcontext.psw.addr & 0x7FFFFFFF;
+#endif
+}
+
+#endif
--
2.7.4