Resubmit r295469 [PGO] Suspend SIGKILL for PR_SET_PDEATHSIG in profile-write
And also r295364 [PGO] remove unintended debug trace. NFC
I removed the test case: it's hard to write synchronized test b/w processes
in this framework. I will revisit the test-case later.
llvm-svn: 298113
diff --git a/compiler-rt/lib/profile/InstrProfilingFile.c b/compiler-rt/lib/profile/InstrProfilingFile.c
index cd3590e..dfcbe52 100644
--- a/compiler-rt/lib/profile/InstrProfilingFile.c
+++ b/compiler-rt/lib/profile/InstrProfilingFile.c
@@ -530,6 +530,7 @@
int rc, Length;
const char *Filename;
char *FilenameBuf;
+ int PDeathSig = 0;
if (lprofProfileDumped()) {
PROF_NOTE("Profile data not written to file: %s.\n",
@@ -556,10 +557,18 @@
return -1;
}
+ // Temporarily suspend getting SIGKILL when the parent exits.
+ PDeathSig = lprofSuspendSigKill();
+
/* Write profile data to the file. */
rc = writeFile(Filename);
if (rc)
PROF_ERR("Failed to write file \"%s\": %s\n", Filename, strerror(errno));
+
+ // Restore SIGKILL.
+ if (PDeathSig == 1)
+ lprofRestoreSigKill();
+
return rc;
}
diff --git a/compiler-rt/lib/profile/InstrProfilingUtil.c b/compiler-rt/lib/profile/InstrProfilingUtil.c
index 321c719..fb68f30 100644
--- a/compiler-rt/lib/profile/InstrProfilingUtil.c
+++ b/compiler-rt/lib/profile/InstrProfilingUtil.c
@@ -29,6 +29,11 @@
#include <stdlib.h>
#include <string.h>
+#if defined(__linux__)
+#include <signal.h>
+#include <sys/prctl.h>
+#endif
+
COMPILER_RT_VISIBILITY
void __llvm_profile_recursive_mkdir(char *path) {
int i;
@@ -219,3 +224,21 @@
#endif
return Sep;
}
+
+COMPILER_RT_VISIBILITY int lprofSuspendSigKill() {
+#if defined(__linux__)
+ int PDeachSig = 0;
+ /* Temporarily suspend getting SIGKILL upon exit of the parent process. */
+ if (prctl(PR_GET_PDEATHSIG, &PDeachSig) == 0 && PDeachSig == SIGKILL)
+ prctl(PR_SET_PDEATHSIG, 0);
+ return (PDeachSig == SIGKILL);
+#else
+ return 0;
+#endif
+}
+
+COMPILER_RT_VISIBILITY void lprofRestoreSigKill() {
+#if defined(__linux__)
+ prctl(PR_SET_PDEATHSIG, SIGKILL);
+#endif
+}
diff --git a/compiler-rt/lib/profile/InstrProfilingUtil.h b/compiler-rt/lib/profile/InstrProfilingUtil.h
index a80fde7..9698599 100644
--- a/compiler-rt/lib/profile/InstrProfilingUtil.h
+++ b/compiler-rt/lib/profile/InstrProfilingUtil.h
@@ -51,4 +51,12 @@
unsigned lprofBoolCmpXchg(void **Ptr, void *OldV, void *NewV);
void *lprofPtrFetchAdd(void **Mem, long ByteIncr);
+/* Temporarily suspend SIGKILL. Return value of 1 means a restore is needed.
+ * Other return values mean no restore is needed.
+ */
+int lprofSuspendSigKill();
+
+/* Restore previously suspended SIGKILL. */
+void lprofRestoreSigKill();
+
#endif /* PROFILE_INSTRPROFILINGUTIL_H */