Fix signal mask save/restore for x86-64.
Bug: 16918359
Change-Id: I30bf61e7d5f1c21daa3a1a21d361e98d77220bf3
diff --git a/libc/arch-x86_64/bionic/setjmp.S b/libc/arch-x86_64/bionic/setjmp.S
index a8f614f..28981fa 100644
--- a/libc/arch-x86_64/bionic/setjmp.S
+++ b/libc/arch-x86_64/bionic/setjmp.S
@@ -48,6 +48,7 @@
#define _JB_PC 7
#define _JB_SIGFLAG 8
#define _JB_SIGMASK 9
+#define _JB_SIGMASK_RT 10 // sigprocmask will write here too.
ENTRY(setjmp)
movl $1,%esi
@@ -62,18 +63,19 @@
// int sigsetjmp(sigjmp_buf env, int save_signal_mask);
ENTRY(sigsetjmp)
// Record whether or not we're saving the signal mask.
- movl %esi,(_JB_SIGFLAG * 8)(%rdi)
+ movl %esi,(_JB_SIGFLAG * 8)(%rdi)
// Do we need to save the signal mask?
testl %esi,%esi
jz 2f
- // Save the signal mask.
- pushq %rdi
- xorq %rdi,%rdi
- call PIC_PLT(sigblock)
- popq %rdi
- movq %rax,(_JB_SIGMASK * 8)(%rdi)
+ // Save current signal mask.
+ pushq %rdi // Push 'env'.
+ // The 'how' argument is ignored if new_mask is NULL.
+ xorq %rsi,%rsi // NULL.
+ leaq (_JB_SIGMASK * 8)(%rdi),%rdx // old_mask.
+ call PIC_PLT(sigprocmask)
+ popq %rdi // Pop 'env'.
2:
// Save the callee-save registers.
@@ -97,12 +99,14 @@
pushq %rsi // Push 'value'.
// Do we need to restore the signal mask?
- cmpl $0, (_JB_SIGFLAG * 8)(%rdi)
+ cmpl $0,(_JB_SIGFLAG * 8)(%rdi)
jz 2f
// Restore the signal mask.
- movq (_JB_SIGMASK * 8)(%rdi),%rdi
- call PIC_PLT(sigsetmask)
+ movq $2,%rdi // SIG_SETMASK.
+ leaq (_JB_SIGMASK * 8)(%r12),%rsi // new_mask.
+ xorq %rdx,%rdx // NULL.
+ call PIC_PLT(sigprocmask)
2:
popq %rax // Pop 'value'.
diff --git a/tests/setjmp_test.cpp b/tests/setjmp_test.cpp
index 2df0135..2ea01b3 100644
--- a/tests/setjmp_test.cpp
+++ b/tests/setjmp_test.cpp
@@ -63,17 +63,29 @@
}
}
-static sigset_t SigSetOf(int signal) {
+static sigset_t SigSetOf(int signal, int rt_signal = 0) {
sigset_t ss;
sigemptyset(&ss);
sigaddset(&ss, signal);
+ if (rt_signal != 0) {
+ sigaddset(&ss, rt_signal);
+ }
return ss;
}
+void AssertSigmaskEquals(const sigset_t& expected) {
+ sigset_t actual;
+ sigprocmask(0 /* ignored */, NULL, &actual);
+ size_t end = sizeof(sigset_t) * 8;
+ for (size_t i = 1; i <= end; ++i) {
+ EXPECT_EQ(sigismember(&expected, i), sigismember(&actual, i)) << i;
+ }
+}
+
TEST(setjmp, _setjmp_signal_mask) {
// _setjmp/_longjmp do not save/restore the signal mask.
- sigset_t ss1(SigSetOf(SIGUSR1));
- sigset_t ss2(SigSetOf(SIGUSR2));
+ sigset_t ss1(SigSetOf(SIGUSR1, SIGRTMIN + 8));
+ sigset_t ss2(SigSetOf(SIGUSR2, SIGRTMIN + 9));
sigset_t original_set;
sigprocmask(SIG_SETMASK, &ss1, &original_set);
jmp_buf jb;
@@ -82,9 +94,7 @@
_longjmp(jb, 1);
FAIL(); // Unreachable.
} else {
- sigset_t ss;
- sigprocmask(SIG_SETMASK, NULL, &ss);
- EXPECT_TRUE(sigismember(&ss, SIGUSR2));
+ AssertSigmaskEquals(ss2);
}
sigprocmask(SIG_SETMASK, &original_set, NULL);
}
@@ -93,8 +103,8 @@
// setjmp/longjmp do save/restore the signal mask on bionic, but not on glibc.
// This is a BSD versus System V historical accident. POSIX leaves the
// behavior unspecified, so any code that cares needs to use sigsetjmp.
- sigset_t ss1(SigSetOf(SIGUSR1));
- sigset_t ss2(SigSetOf(SIGUSR2));
+ sigset_t ss1(SigSetOf(SIGUSR1, SIGRTMIN + 8));
+ sigset_t ss2(SigSetOf(SIGUSR2, SIGRTMIN + 9));
sigset_t original_set;
sigprocmask(SIG_SETMASK, &ss1, &original_set);
jmp_buf jb;
@@ -103,14 +113,12 @@
longjmp(jb, 1);
FAIL(); // Unreachable.
} else {
- sigset_t ss;
- sigprocmask(SIG_SETMASK, NULL, &ss);
#if defined(__BIONIC__)
// bionic behaves like BSD and does save/restore the signal mask.
- EXPECT_TRUE(sigismember(&ss, SIGUSR1));
+ AssertSigmaskEquals(ss1);
#else
// glibc behaves like System V and doesn't save/restore the signal mask.
- EXPECT_TRUE(sigismember(&ss, SIGUSR2));
+ AssertSigmaskEquals(ss2);
#endif
}
sigprocmask(SIG_SETMASK, &original_set, NULL);
@@ -118,8 +126,8 @@
TEST(setjmp, sigsetjmp_0_signal_mask) {
// sigsetjmp(0)/siglongjmp do not save/restore the signal mask.
- sigset_t ss1(SigSetOf(SIGUSR1));
- sigset_t ss2(SigSetOf(SIGUSR2));
+ sigset_t ss1(SigSetOf(SIGUSR1, SIGRTMIN + 8));
+ sigset_t ss2(SigSetOf(SIGUSR2, SIGRTMIN + 9));
sigset_t original_set;
sigprocmask(SIG_SETMASK, &ss1, &original_set);
sigjmp_buf sjb;
@@ -128,17 +136,15 @@
siglongjmp(sjb, 1);
FAIL(); // Unreachable.
} else {
- sigset_t ss;
- sigprocmask(SIG_SETMASK, NULL, &ss);
- EXPECT_TRUE(sigismember(&ss, SIGUSR2));
+ AssertSigmaskEquals(ss2);
}
sigprocmask(SIG_SETMASK, &original_set, NULL);
}
TEST(setjmp, sigsetjmp_1_signal_mask) {
// sigsetjmp(1)/siglongjmp does save/restore the signal mask.
- sigset_t ss1(SigSetOf(SIGUSR1));
- sigset_t ss2(SigSetOf(SIGUSR2));
+ sigset_t ss1(SigSetOf(SIGUSR1, SIGRTMIN + 8));
+ sigset_t ss2(SigSetOf(SIGUSR2, SIGRTMIN + 9));
sigset_t original_set;
sigprocmask(SIG_SETMASK, &ss1, &original_set);
sigjmp_buf sjb;
@@ -147,9 +153,7 @@
siglongjmp(sjb, 1);
FAIL(); // Unreachable.
} else {
- sigset_t ss;
- sigprocmask(SIG_SETMASK, NULL, &ss);
- EXPECT_TRUE(sigismember(&ss, SIGUSR1));
+ AssertSigmaskEquals(ss1);
}
sigprocmask(SIG_SETMASK, &original_set, NULL);
}