8227275: Within native OOM error handling, assertions may hang the process
Reviewed-by: mdoerr, coleenp
--- a/src/hotspot/os/posix/vmError_posix.cpp Thu Jul 11 06:49:49 2019 +0200
+++ b/src/hotspot/os/posix/vmError_posix.cpp Thu Jul 11 06:56:51 2019 +0200
@@ -132,8 +132,9 @@
// Needed because asserts may happen in error handling too.
#ifdef CAN_SHOW_REGISTERS_ON_ASSERT
if ((sig == SIGSEGV || sig == SIGBUS) && info != NULL && info->si_addr == g_assert_poison) {
- handle_assert_poison_fault(ucVoid, info->si_addr);
- return;
+ if (handle_assert_poison_fault(ucVoid, info->si_addr)) {
+ return;
+ }
}
#endif // CAN_SHOW_REGISTERS_ON_ASSERT
--- a/src/hotspot/os_cpu/linux_aarch64/os_linux_aarch64.cpp Thu Jul 11 06:49:49 2019 +0200
+++ b/src/hotspot/os_cpu/linux_aarch64/os_linux_aarch64.cpp Thu Jul 11 06:56:51 2019 +0200
@@ -279,8 +279,9 @@
#ifdef CAN_SHOW_REGISTERS_ON_ASSERT
if ((sig == SIGSEGV || sig == SIGBUS) && info != NULL && info->si_addr == g_assert_poison) {
- handle_assert_poison_fault(ucVoid, info->si_addr);
- return 1;
+ if (handle_assert_poison_fault(ucVoid, info->si_addr)) {
+ return 1;
+ }
}
#endif
--- a/src/hotspot/os_cpu/linux_arm/os_linux_arm.cpp Thu Jul 11 06:49:49 2019 +0200
+++ b/src/hotspot/os_cpu/linux_arm/os_linux_arm.cpp Thu Jul 11 06:56:51 2019 +0200
@@ -301,8 +301,9 @@
#ifdef CAN_SHOW_REGISTERS_ON_ASSERT
if ((sig == SIGSEGV || sig == SIGBUS) && info != NULL && info->si_addr == g_assert_poison) {
- handle_assert_poison_fault(ucVoid, info->si_addr);
- return 1;
+ if (handle_assert_poison_fault(ucVoid, info->si_addr)) {
+ return 1;
+ }
}
#endif
--- a/src/hotspot/os_cpu/linux_ppc/os_linux_ppc.cpp Thu Jul 11 06:49:49 2019 +0200
+++ b/src/hotspot/os_cpu/linux_ppc/os_linux_ppc.cpp Thu Jul 11 06:56:51 2019 +0200
@@ -271,8 +271,9 @@
#ifdef CAN_SHOW_REGISTERS_ON_ASSERT
if ((sig == SIGSEGV || sig == SIGBUS) && info != NULL && info->si_addr == g_assert_poison) {
- handle_assert_poison_fault(ucVoid, info->si_addr);
- return 1;
+ if (handle_assert_poison_fault(ucVoid, info->si_addr)) {
+ return 1;
+ }
}
#endif
--- a/src/hotspot/os_cpu/linux_s390/os_linux_s390.cpp Thu Jul 11 06:49:49 2019 +0200
+++ b/src/hotspot/os_cpu/linux_s390/os_linux_s390.cpp Thu Jul 11 06:56:51 2019 +0200
@@ -270,8 +270,9 @@
#ifdef CAN_SHOW_REGISTERS_ON_ASSERT
if ((sig == SIGSEGV || sig == SIGBUS) && info != NULL && info->si_addr == g_assert_poison) {
- handle_assert_poison_fault(ucVoid, info->si_addr);
- return 1;
+ if (handle_assert_poison_fault(ucVoid, info->si_addr)) {
+ return 1;
+ }
}
#endif
--- a/src/hotspot/os_cpu/linux_sparc/os_linux_sparc.cpp Thu Jul 11 06:49:49 2019 +0200
+++ b/src/hotspot/os_cpu/linux_sparc/os_linux_sparc.cpp Thu Jul 11 06:56:51 2019 +0200
@@ -514,8 +514,9 @@
#ifdef CAN_SHOW_REGISTERS_ON_ASSERT
if ((sig == SIGSEGV || sig == SIGBUS) && info != NULL && info->si_addr == g_assert_poison) {
- handle_assert_poison_fault(ucVoid, info->si_addr);
- return 1;
+ if (handle_assert_poison_fault(ucVoid, info->si_addr)) {
+ return 1;
+ }
}
#endif
--- a/src/hotspot/os_cpu/linux_x86/os_linux_x86.cpp Thu Jul 11 06:49:49 2019 +0200
+++ b/src/hotspot/os_cpu/linux_x86/os_linux_x86.cpp Thu Jul 11 06:56:51 2019 +0200
@@ -303,8 +303,9 @@
#ifdef CAN_SHOW_REGISTERS_ON_ASSERT
if ((sig == SIGSEGV || sig == SIGBUS) && info != NULL && info->si_addr == g_assert_poison) {
- handle_assert_poison_fault(ucVoid, info->si_addr);
- return 1;
+ if (handle_assert_poison_fault(ucVoid, info->si_addr)) {
+ return 1;
+ }
}
#endif
--- a/src/hotspot/share/utilities/debug.cpp Thu Jul 11 06:49:49 2019 +0200
+++ b/src/hotspot/share/utilities/debug.cpp Thu Jul 11 06:56:51 2019 +0200
@@ -734,6 +734,10 @@
}
}
+void disarm_assert_poison() {
+ g_assert_poison = &g_dummy;
+}
+
static void store_context(const void* context) {
memcpy(&g_stored_assertion_context, context, sizeof(ucontext_t));
#if defined(__linux) && defined(PPC64)
@@ -746,7 +750,14 @@
bool handle_assert_poison_fault(const void* ucVoid, const void* faulting_address) {
if (faulting_address == g_assert_poison) {
// Disarm poison page.
- os::protect_memory((char*)g_assert_poison, os::vm_page_size(), os::MEM_PROT_RWX);
+ if (os::protect_memory((char*)g_assert_poison, os::vm_page_size(), os::MEM_PROT_RWX) == false) {
+#ifdef ASSERT
+ fprintf(stderr, "Assertion poison page cannot be unprotected - mprotect failed with %d (%s)",
+ errno, os::strerror(errno));
+ fflush(stderr);
+#endif
+ return false; // unprotecting memory may fail in OOM situations, as surprising as this sounds.
+ }
// Store Context away.
if (ucVoid) {
const intx my_tid = os::current_thread_id();
--- a/src/hotspot/share/utilities/debug.hpp Thu Jul 11 06:49:49 2019 +0200
+++ b/src/hotspot/share/utilities/debug.hpp Thu Jul 11 06:56:51 2019 +0200
@@ -37,6 +37,7 @@
extern char* g_assert_poison;
#define TOUCH_ASSERT_POISON (*g_assert_poison) = 'X';
void initialize_assert_poison();
+void disarm_assert_poison();
bool handle_assert_poison_fault(const void* ucVoid, const void* faulting_address);
#else
#define TOUCH_ASSERT_POISON
--- a/src/hotspot/share/utilities/vmError.cpp Thu Jul 11 06:49:49 2019 +0200
+++ b/src/hotspot/share/utilities/vmError.cpp Thu Jul 11 06:56:51 2019 +0200
@@ -1327,6 +1327,12 @@
// File descriptor to the error log file.
static int fd_log = -1;
+#ifdef CAN_SHOW_REGISTERS_ON_ASSERT
+ // Disarm assertion poison page, since from this point on we do not need this mechanism anymore and it may
+ // cause problems in error handling during native OOM, see JDK-8227275.
+ disarm_assert_poison();
+#endif
+
// Use local fdStream objects only. Do not use global instances whose initialization
// relies on dynamic initialization (see JDK-8214975). Do not rely on these instances
// to carry over into recursions or invocations from other threads.