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Fix linux-gate handling in LinuxDumper so it gets a valid debug ID

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A=ted R=nealsid at http://breakpad.appspot.com/284001

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@788 4c0a9323-5329-0410-9bdc-e9ce6186880e
This commit is contained in:
ted.mielczarek 2011-05-06 23:23:31 +00:00
parent 04023b1f6a
commit 1807e385d7
2 changed files with 92 additions and 2 deletions
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15
src/client/linux/minidump_writer/linux_dumper.cc
View file

@ -213,6 +213,21 @@ LinuxDumper::ElfFileIdentifierForMapping(const MappingInfo& mapping,
if (IsMappedFileOpenUnsafe(mapping))
return false;
// Special-case linux-gate because it's not a real file.
if (my_strcmp(mapping.name, kLinuxGateLibraryName) == 0) {
const uintptr_t kPageSize = getpagesize();
void* linux_gate = NULL;
if (pid_ == sys_getpid()) {
linux_gate = reinterpret_cast<void*>(mapping.start_addr);
} else {
linux_gate = allocator_.Alloc(kPageSize);
CopyFromProcess(linux_gate, pid_,
reinterpret_cast<const void*>(mapping.start_addr),
kPageSize);
}
return FileID::ElfFileIdentifierFromMappedFile(linux_gate, identifier);
}
char filename[NAME_MAX];
size_t filename_len = my_strlen(mapping.name);
assert(filename_len < NAME_MAX);

79
src/client/linux/minidump_writer/linux_dumper_unittest.cc
View file

@ -276,6 +276,7 @@ TEST(LinuxDumperTest, BuildProcPath) {
}
#if !defined(__ARM_EABI__)
// Ensure that the linux-gate VDSO is included in the mapping list.
TEST(LinuxDumperTest, MappingsIncludeLinuxGate) {
LinuxDumper dumper(getpid());
ASSERT_TRUE(dumper.Init());
@ -297,6 +298,80 @@ TEST(LinuxDumperTest, MappingsIncludeLinuxGate) {
EXPECT_EQ(linux_gate_loc, reinterpret_cast<void*>(mapping->start_addr));
EXPECT_EQ(0, memcmp(linux_gate_loc, ELFMAG, SELFMAG));
}
// Ensure that the linux-gate VDSO can generate a non-zeroed File ID.
TEST(LinuxDumperTest, LinuxGateMappingID) {
LinuxDumper dumper(getpid());
ASSERT_TRUE(dumper.Init());
bool found_linux_gate = false;
const wasteful_vector<MappingInfo*> mappings = dumper.mappings();
unsigned index = 0;
for (unsigned i = 0; i < mappings.size(); ++i) {
if (!strcmp(mappings[i]->name, kLinuxGateLibraryName)) {
found_linux_gate = true;
index = i;
break;
}
}
ASSERT_TRUE(found_linux_gate);
uint8_t identifier[sizeof(MDGUID)];
ASSERT_TRUE(dumper.ElfFileIdentifierForMapping(*mappings[index],
true,
index,
identifier));
uint8_t empty_identifier[sizeof(MDGUID)];
memset(empty_identifier, 0, sizeof(empty_identifier));
EXPECT_NE(0, memcmp(empty_identifier, identifier, sizeof(identifier)));
}
// Ensure that the linux-gate VDSO can generate a non-zeroed File ID
// from a child process.
TEST(LinuxDumperTest, LinuxGateMappingIDChild) {
int fds[2];
ASSERT_NE(-1, pipe(fds));
// Fork a child so ptrace works.
const pid_t child = fork();
if (child == 0) {
close(fds[1]);
// Now wait forever for the parent.
char b;
HANDLE_EINTR(read(fds[0], &b, sizeof(b)));
close(fds[0]);
syscall(__NR_exit);
}
close(fds[0]);
LinuxDumper dumper(child);
ASSERT_TRUE(dumper.Init());
bool found_linux_gate = false;
const wasteful_vector<MappingInfo*> mappings = dumper.mappings();
unsigned index = 0;
for (unsigned i = 0; i < mappings.size(); ++i) {
if (!strcmp(mappings[i]->name, kLinuxGateLibraryName)) {
found_linux_gate = true;
index = i;
break;
}
}
ASSERT_TRUE(found_linux_gate);
// Need to suspend the child so ptrace actually works.
ASSERT_TRUE(dumper.ThreadsSuspend());
uint8_t identifier[sizeof(MDGUID)];
ASSERT_TRUE(dumper.ElfFileIdentifierForMapping(*mappings[index],
true,
index,
identifier));
uint8_t empty_identifier[sizeof(MDGUID)];
memset(empty_identifier, 0, sizeof(empty_identifier));
EXPECT_NE(0, memcmp(empty_identifier, identifier, sizeof(identifier)));
EXPECT_TRUE(dumper.ThreadsResume());
close(fds[1]);
}
#endif
TEST(LinuxDumperTest, FileIDsMatch) {
@ -311,11 +386,11 @@ TEST(LinuxDumperTest, FileIDsMatch) {
int fds[2];
ASSERT_NE(-1, pipe(fds));
// fork a child so we can ptrace it
// Fork a child so ptrace works.
const pid_t child = fork();
if (child == 0) {
close(fds[1]);
// now wait forever for the parent
// Now wait forever for the parent.
char b;
HANDLE_EINTR(read(fds[0], &b, sizeof(b)));
close(fds[0]);