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Merge adjacent mappings with the same name into one module in LinuxDumper.

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A=Mike Hommey <mh+mozilla@glandium.org> R=ted at https://bugzilla.mozilla.org/show_bug.cgi?id=637316

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@781 4c0a9323-5329-0410-9bdc-e9ce6186880e
This commit is contained in:
ted.mielczarek 2011-03-14 17:04:09 +00:00
parent 88fa7cfc6b
commit b0201df935
2 changed files with 117 additions and 23 deletions
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33
src/client/linux/minidump_writer/linux_dumper.cc
View file

@ -306,25 +306,36 @@ LinuxDumper::EnumerateMappings(wasteful_vector<MappingInfo*>* result) const {
if (*i2 == ' ') {
const char* i3 = my_read_hex_ptr(&offset, i2 + 6 /* skip ' rwxp ' */);
if (*i3 == ' ') {
const char* name = NULL;
// Only copy name if the name is a valid path name, or if
// it's the VDSO image.
if (((name = my_strchr(line, '/')) == NULL) &&
linux_gate_loc &&
reinterpret_cast<void*>(start_addr) == linux_gate_loc) {
name = kLinuxGateLibraryName;
offset = 0;
}
// Merge adjacent mappings with the same name into one module,
// assuming they're a single library mapped by the dynamic linker
if (name && result->size()) {
MappingInfo* module = (*result)[result->size() - 1];
if ((start_addr == module->start_addr + module->size) &&
(my_strlen(name) == my_strlen(module->name)) &&
(my_strncmp(name, module->name, my_strlen(name)) == 0)) {
module->size = end_addr - module->start_addr;
line_reader->PopLine(line_len);
continue;
}
}
MappingInfo* const module = new(allocator_) MappingInfo;
memset(module, 0, sizeof(MappingInfo));
module->start_addr = start_addr;
module->size = end_addr - start_addr;
module->offset = offset;
const char* name = NULL;
// Only copy name if the name is a valid path name, or if
// it's the VDSO image.
if ((name = my_strchr(line, '/')) != NULL) {
if (name != NULL) {
const unsigned l = my_strlen(name);
if (l < sizeof(module->name))
memcpy(module->name, name, l);
} else if (linux_gate_loc &&
reinterpret_cast<void*>(module->start_addr) ==
linux_gate_loc) {
memcpy(module->name,
kLinuxGateLibraryName,
my_strlen(kLinuxGateLibraryName));
module->offset = 0;
}
result->push_back(module);
}

107
src/client/linux/minidump_writer/linux_dumper_unittest.cc
View file

@ -33,6 +33,7 @@
#include <unistd.h>
#include <signal.h>
#include <stdint.h>
#include <sys/mman.h>
#include <sys/poll.h>
#include <sys/types.h>
@ -47,6 +48,24 @@ using namespace google_breakpad;
namespace {
typedef testing::Test LinuxDumperTest;
string GetHelperBinary() {
// Locate helper binary next to the current binary.
char self_path[PATH_MAX];
if (readlink("/proc/self/exe", self_path, sizeof(self_path) - 1) == -1) {
return "";
}
string helper_path(self_path);
size_t pos = helper_path.rfind('/');
if (pos == string::npos) {
return "";
}
helper_path.erase(pos + 1);
helper_path += "linux_dumper_unittest_helper";
return helper_path;
}
}
TEST(LinuxDumperTest, Setup) {
@ -76,6 +95,79 @@ TEST(LinuxDumperTest, ThreadList) {
}
}
// Helper stack class to close a file descriptor and unmap
// a mmap'ed mapping.
class StackHelper {
public:
StackHelper(int fd, char* mapping, size_t size)
: fd_(fd), mapping_(mapping), size_(size) {}
~StackHelper() {
munmap(mapping_, size_);
close(fd_);
}
private:
int fd_;
char* mapping_;
size_t size_;
};
TEST(LinuxDumperTest, MergedMappings) {
string helper_path(GetHelperBinary());
if (helper_path.empty()) {
FAIL() << "Couldn't find helper binary";
exit(1);
}
// mmap two segments out of the helper binary, one
// enclosed in the other, but with different protections.
const size_t kPageSize = sysconf(_SC_PAGESIZE);
const size_t kMappingSize = 3 * kPageSize;
int fd = open(helper_path.c_str(), O_RDONLY);
ASSERT_NE(-1, fd);
char* mapping =
reinterpret_cast<char*>(mmap(NULL,
kMappingSize,
PROT_READ,
MAP_SHARED,
fd,
0));
ASSERT_TRUE(mapping);
const u_int64_t kMappingAddress = reinterpret_cast<u_int64_t>(mapping);
// Ensure that things get cleaned up.
StackHelper helper(fd, mapping, kMappingSize);
// Carve a page out of the first mapping with different permissions.
char* inside_mapping = reinterpret_cast<char*>(mmap(mapping + 2 *kPageSize,
kPageSize,
PROT_NONE,
MAP_SHARED | MAP_FIXED,
fd,
// Map a different offset just to
// better test real-world conditions.
kPageSize));
ASSERT_TRUE(inside_mapping);
// Now check that LinuxDumper interpreted the mappings properly.
LinuxDumper dumper(getpid());
ASSERT_TRUE(dumper.Init());
int mapping_count = 0;
for (unsigned i = 0; i < dumper.mappings().size(); ++i) {
const MappingInfo& mapping = *dumper.mappings()[i];
if (strcmp(mapping.name, helper_path.c_str()) == 0) {
// This mapping should encompass the entire original mapped
// range.
EXPECT_EQ(kMappingAddress, mapping.start_addr);
EXPECT_EQ(kMappingSize, mapping.size);
EXPECT_EQ(0, mapping.offset);
mapping_count++;
}
}
EXPECT_EQ(1, mapping_count);
}
TEST(LinuxDumperTest, VerifyStackReadWithMultipleThreads) {
static const int kNumberOfThreadsInHelperProgram = 5;
char kNumberOfThreadsArgument[2];
@ -89,20 +181,11 @@ TEST(LinuxDumperTest, VerifyStackReadWithMultipleThreads) {
// In child process.
close(fds[0]);
// Locate helper binary next to the current binary.
char self_path[PATH_MAX];
if (readlink("/proc/self/exe", self_path, sizeof(self_path) - 1) == -1) {
FAIL() << "readlink failed: " << strerror(errno);
string helper_path(GetHelperBinary());
if (helper_path.empty()) {
FAIL() << "Couldn't find helper binary";
exit(1);
}
string helper_path(self_path);
size_t pos = helper_path.rfind('/');
if (pos == string::npos) {
FAIL() << "no trailing slash in path: " << helper_path;
exit(1);
}
helper_path.erase(pos + 1);
helper_path += "linux_dumper_unittest_helper";
// Pass the pipe fd and the number of threads as arguments.
char pipe_fd_string[8];