* [2.28 COMMITTED] RISC-V: Fix elfutils testsuite unwind failures.
@ 2019-01-01 0:00 Aurelien Jarno
0 siblings, 0 replies; only message in thread
From: Aurelien Jarno @ 2019-01-01 0:00 UTC (permalink / raw)
To: libc-stable; +Cc: Jim Wilson
From: Jim Wilson <jimw@sifive.com>
The clone.S patch fixes 2 elfutils testsuite unwind failures, where the
backtrace gets stuck repeating __thread_start until we hit the backtrace
limit. This was confirmed by building and installing a patched glibc and
then building elfutils and running its testsuite.
Unfortunately, the testcase isn't working as expected and I don't know why.
The testcase passes even when my clone.S patch is not installed. The testcase
looks logically similarly to the elfutils testcases that are failing. Maybe
there is a subtle difference in how the glibc unwinding works versus the
elfutils unwinding? I don't have good gdb pthread support yet, so I haven't
found a way to debug this. Anyways, I don't know if the testcase is useful or
not. If the testcase isn't useful then maybe the clone.S patch is OK without
a testcase?
Jim
[BZ #24040]
* elf/Makefile (CFLAGS-tst-unwind-main.c): Add -DUSE_PTHREADS=0.
* elf/tst-unwind-main.c: If USE_PTHEADS, include pthread.h and error.h
(func): New.
(main): If USE_PTHREADS, call pthread_create to run func. Otherwise
call func directly.
* nptl/Makefile (tests): Add tst-unwind-thread.
(CFLAGS-tst-unwind-thread.c): Define.
* nptl/tst-unwind-thread.c: New file.
* sysdeps/unix/sysv/linux/riscv/clone.S (__thread_start): Mark ra
as undefined.
(cherry picked from commit 85bd1ddbdfdfd13cfd06f7c367519b6ed3360843)
---
ChangeLog | 14 ++++++++++++++
NEWS | 1 +
elf/Makefile | 2 +-
elf/tst-unwind-main.c | 28 ++++++++++++++++++++++++---
nptl/Makefile | 5 ++++-
nptl/tst-unwind-thread.c | 2 ++
sysdeps/unix/sysv/linux/riscv/clone.S | 5 +++++
7 files changed, 52 insertions(+), 5 deletions(-)
create mode 100644 nptl/tst-unwind-thread.c
diff --git a/ChangeLog b/ChangeLog
index 06de839fbe..0087fd9d50 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2019-01-13 Jim Wilson <jimw@sifive.com>
+
+ [BZ #24040]
+ * elf/Makefile (CFLAGS-tst-unwind-main.c): Add -DUSE_PTHREADS=0.
+ * elf/tst-unwind-main.c: If USE_PTHEADS, include pthread.h and error.h
+ (func): New.
+ (main): If USE_PTHREADS, call pthread_create to run func. Otherwise
+ call func directly.
+ * nptl/Makefile (tests): Add tst-unwind-thread.
+ (CFLAGS-tst-unwind-thread.c): Define.
+ * nptl/tst-unwind-thread.c: New file.
+ * sysdeps/unix/sysv/linux/riscv/clone.S (__thread_start): Mark ra
+ as undefined.
+
2019-01-31 Carlos O'Donell <carlos@redhat.com>
Torvald Riegel <triegel@redhat.com>
Rik Prohaska <prohaska7@gmail.com>
diff --git a/NEWS b/NEWS
index d794e5bf09..2d5a514dfd 100644
--- a/NEWS
+++ b/NEWS
@@ -36,6 +36,7 @@ The following bugs are resolved with this release:
[24024] strerror() might set errno to ENOMEM due to -fno-math-error
[24027] malloc: Integer overflow in realloc
[24034] tst-cancel21-static fails with SIGBUS on pre-ARMv7 when using GCC 8
+ [24040] riscv64: unterminated call chain in __thread_start
[24097] Can't use 64-bit register for size_t in assembly codes for x32 (CVE-2019-6488)
[24155] x32 memcmp can treat positive length as 0 (if sign bit in RDX is set) (CVE-2019-7309)
[24161] __run_fork_handlers self-deadlocks in malloc/tst-mallocfork2
diff --git a/elf/Makefile b/elf/Makefile
index 43f625af05..6027926bd1 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -1486,4 +1486,4 @@ $(objpfx)tst-libc_dlvsym-static.out: $(objpfx)tst-libc_dlvsym-dso.so
$(objpfx)tst-big-note: $(objpfx)tst-big-note-lib.so
-CFLAGS-tst-unwind-main.c += -funwind-tables
+CFLAGS-tst-unwind-main.c += -funwind-tables -DUSE_PTHREADS=0
diff --git a/elf/tst-unwind-main.c b/elf/tst-unwind-main.c
index d1236032d7..7c20f04743 100644
--- a/elf/tst-unwind-main.c
+++ b/elf/tst-unwind-main.c
@@ -20,19 +20,41 @@
#include <unistd.h>
#include <support/test-driver.h>
+#if USE_PTHREADS
+# include <pthread.h>
+# include <error.h>
+#endif
+
static _Unwind_Reason_Code
callback (struct _Unwind_Context *ctx, void *arg)
{
return _URC_NO_REASON;
}
-int
-main (void)
+static void *
+func (void *a)
{
/* Arrange for this test to be killed if _Unwind_Backtrace runs into an
endless loop. We cannot use the test driver because the complete
call chain needs to be compiled with -funwind-tables so that
- _Unwind_Backtrace is able to reach _start. */
+ _Unwind_Backtrace is able to reach the start routine. */
alarm (DEFAULT_TIMEOUT);
_Unwind_Backtrace (callback, 0);
+ return a;
+}
+
+int
+main (void)
+{
+#if USE_PTHREADS
+ pthread_t thr;
+ int rc = pthread_create (&thr, NULL, &func, NULL);
+ if (rc)
+ error (1, rc, "pthread_create");
+ rc = pthread_join (thr, NULL);
+ if (rc)
+ error (1, rc, "pthread_join");
+#else
+ func (NULL);
+#endif
}
diff --git a/nptl/Makefile b/nptl/Makefile
index b1003cf56b..5be7655529 100644
--- a/nptl/Makefile
+++ b/nptl/Makefile
@@ -320,7 +320,8 @@ tests = tst-attr1 tst-attr2 tst-attr3 tst-default-attr \
tst-cnd-timedwait tst-thrd-detach tst-mtx-basic tst-thrd-sleep \
tst-mtx-recursive tst-tss-basic tst-call-once tst-mtx-timedlock \
tst-rwlock-pwn \
- tst-rwlock-tryrdlock-stall tst-rwlock-trywrlock-stall
+ tst-rwlock-tryrdlock-stall tst-rwlock-trywrlock-stall \
+ tst-unwind-thread
tests-internal := tst-rwlock19 tst-rwlock20 \
tst-sem11 tst-sem12 tst-sem13 \
@@ -723,6 +724,8 @@ $(objpfx)tst-audit-threads: $(objpfx)tst-audit-threads-mod2.so
$(objpfx)tst-audit-threads.out: $(objpfx)tst-audit-threads-mod1.so
tst-audit-threads-ENV = LD_AUDIT=$(objpfx)tst-audit-threads-mod1.so
+CFLAGS-tst-unwind-thread.c += -funwind-tables
+
# The tests here better do not run in parallel
ifneq ($(filter %tests,$(MAKECMDGOALS)),)
.NOTPARALLEL:
diff --git a/nptl/tst-unwind-thread.c b/nptl/tst-unwind-thread.c
new file mode 100644
index 0000000000..d5c38e3709
--- /dev/null
+++ b/nptl/tst-unwind-thread.c
@@ -0,0 +1,2 @@
+#define USE_PTHREADS 1
+#include "../elf/tst-unwind-main.c"
diff --git a/sysdeps/unix/sysv/linux/riscv/clone.S b/sysdeps/unix/sysv/linux/riscv/clone.S
index 392af72b55..1c5b12566e 100644
--- a/sysdeps/unix/sysv/linux/riscv/clone.S
+++ b/sysdeps/unix/sysv/linux/riscv/clone.S
@@ -69,6 +69,11 @@ L (error):
ENTRY (__thread_start)
L (thread_start):
+ /* Terminate call stack by noting ra is undefined. Use a dummy
+ .cfi_label to force starting the FDE. */
+ .cfi_label .Ldummy
+ cfi_undefined (ra)
+
/* Restore the arg for user's function. */
REG_L a1,0(sp) /* Function pointer. */
REG_L a0,SZREG(sp) /* Argument pointer. */
--
2.20.1
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