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Merge "Create a debugger_process_info data structure with the process info pointers." am: 5677803cb7 am: cba2467937

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Change-Id: I1cfcdce3a24ddafbdc2f89202405908555e98a24
This commit is contained in:
Peter Collingbourne 2020-03-30 22:27:23 +00:00 committed by Automerger Merge Worker
commit c137271d87
5 changed files with 63 additions and 65 deletions
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30
debuggerd/crash_dump.cpp
View file

@ -264,15 +264,13 @@ static void ReadCrashInfo(unique_fd& fd, siginfo_t* siginfo,
ssize_t expected_size = 0;
switch (crash_info->header.version) {
case 1:
expected_size = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataV1);
break;
case 2:
expected_size = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataV2);
case 3:
expected_size = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataStatic);
break;
case 3:
expected_size = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataV3);
case 4:
expected_size = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataDynamic);
break;
default:
@ -280,25 +278,25 @@ static void ReadCrashInfo(unique_fd& fd, siginfo_t* siginfo,
break;
};
if (rc != expected_size) {
if (rc < expected_size) {
LOG(FATAL) << "read " << rc << " bytes when reading target crash information, expected "
<< expected_size;
}
}
switch (crash_info->header.version) {
case 3:
process_info->gwp_asan_state = crash_info->data.v3.gwp_asan_state;
process_info->gwp_asan_metadata = crash_info->data.v3.gwp_asan_metadata;
FALLTHROUGH_INTENDED;
case 2:
process_info->fdsan_table_address = crash_info->data.v2.fdsan_table_address;
case 4:
process_info->fdsan_table_address = crash_info->data.d.fdsan_table_address;
process_info->gwp_asan_state = crash_info->data.d.gwp_asan_state;
process_info->gwp_asan_metadata = crash_info->data.d.gwp_asan_metadata;
FALLTHROUGH_INTENDED;
case 1:
process_info->abort_msg_address = crash_info->data.v1.abort_msg_address;
*siginfo = crash_info->data.v1.siginfo;
case 2:
case 3:
process_info->abort_msg_address = crash_info->data.s.abort_msg_address;
*siginfo = crash_info->data.s.siginfo;
regs->reset(unwindstack::Regs::CreateFromUcontext(unwindstack::Regs::CurrentArch(),
&crash_info->data.v1.ucontext));
&crash_info->data.s.ucontext));
break;
default:

6
debuggerd/crasher/crasher.cpp
View file

@ -349,7 +349,7 @@ noinline int do_action(const char* arg) {
int main(int argc, char** argv) {
#if defined(STATIC_CRASHER)
debuggerd_callbacks_t callbacks = {
.get_abort_message = []() {
.get_process_info = []() {
static struct {
size_t size;
char msg[32];
@ -357,7 +357,9 @@ int main(int argc, char** argv) {
msg.size = strlen("dummy abort message");
memcpy(msg.msg, "dummy abort message", strlen("dummy abort message"));
return reinterpret_cast<abort_msg_t*>(&msg);
return debugger_process_info{
.abort_msg = reinterpret_cast<void*>(&msg),
};
},
.post_dump = nullptr
};

67
debuggerd/handler/debuggerd_handler.cpp
View file

@ -297,10 +297,7 @@ struct debugger_thread_info {
pid_t pseudothread_tid;
siginfo_t* siginfo;
void* ucontext;
uintptr_t abort_msg;
uintptr_t fdsan_table;
uintptr_t gwp_asan_state;
uintptr_t gwp_asan_metadata;
debugger_process_info process_info;
};
// Logging and contacting debuggerd requires free file descriptors, which we might not have.
@ -344,25 +341,36 @@ static int debuggerd_dispatch_pseudothread(void* arg) {
fatal_errno("failed to create pipe");
}
// ucontext_t is absurdly large on AArch64, so piece it together manually with writev.
uint32_t version = 3;
constexpr size_t expected = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataV3);
uint32_t version;
ssize_t expected;
// ucontext_t is absurdly large on AArch64, so piece it together manually with writev.
struct iovec iovs[4] = {
{.iov_base = &version, .iov_len = sizeof(version)},
{.iov_base = thread_info->siginfo, .iov_len = sizeof(siginfo_t)},
{.iov_base = thread_info->ucontext, .iov_len = sizeof(ucontext_t)},
};
if (thread_info->process_info.fdsan_table) {
// Dynamic executables always use version 4. There is no need to increment the version number if
// the format changes, because the sender (linker) and receiver (crash_dump) are version locked.
version = 4;
expected = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataDynamic);
iovs[3] = {.iov_base = &thread_info->process_info,
.iov_len = sizeof(thread_info->process_info)};
} else {
// Static executables always use version 1.
version = 1;
expected = sizeof(CrashInfoHeader) + sizeof(CrashInfoDataStatic);
iovs[3] = {.iov_base = &thread_info->process_info.abort_msg, .iov_len = sizeof(uintptr_t)};
}
errno = 0;
if (fcntl(output_write.get(), F_SETPIPE_SZ, expected) < static_cast<int>(expected)) {
fatal_errno("failed to set pipe buffer size");
}
struct iovec iovs[] = {
{.iov_base = &version, .iov_len = sizeof(version)},
{.iov_base = thread_info->siginfo, .iov_len = sizeof(siginfo_t)},
{.iov_base = thread_info->ucontext, .iov_len = sizeof(ucontext_t)},
{.iov_base = &thread_info->abort_msg, .iov_len = sizeof(uintptr_t)},
{.iov_base = &thread_info->fdsan_table, .iov_len = sizeof(uintptr_t)},
{.iov_base = &thread_info->gwp_asan_state, .iov_len = sizeof(uintptr_t)},
{.iov_base = &thread_info->gwp_asan_metadata, .iov_len = sizeof(uintptr_t)},
};
ssize_t rc = TEMP_FAILURE_RETRY(writev(output_write.get(), iovs, arraysize(iovs)));
if (rc == -1) {
fatal_errno("failed to write crash info");
@ -489,29 +497,19 @@ static void debuggerd_signal_handler(int signal_number, siginfo_t* info, void* c
// check to allow all si_code values in calls coming from inside the house.
}
void* abort_message = nullptr;
const gwp_asan::AllocatorState* gwp_asan_state = nullptr;
const gwp_asan::AllocationMetadata* gwp_asan_metadata = nullptr;
debugger_process_info process_info = {};
uintptr_t si_val = reinterpret_cast<uintptr_t>(info->si_ptr);
if (signal_number == BIONIC_SIGNAL_DEBUGGER) {
if (info->si_code == SI_QUEUE && info->si_pid == __getpid()) {
// Allow for the abort message to be explicitly specified via the sigqueue value.
// Keep the bottom bit intact for representing whether we want a backtrace or a tombstone.
if (si_val != kDebuggerdFallbackSivalUintptrRequestDump) {
abort_message = reinterpret_cast<void*>(si_val & ~1);
process_info.abort_msg = reinterpret_cast<void*>(si_val & ~1);
info->si_ptr = reinterpret_cast<void*>(si_val & 1);
}
}
} else {
if (g_callbacks.get_abort_message) {
abort_message = g_callbacks.get_abort_message();
}
if (g_callbacks.get_gwp_asan_state) {
gwp_asan_state = g_callbacks.get_gwp_asan_state();
}
if (g_callbacks.get_gwp_asan_metadata) {
gwp_asan_metadata = g_callbacks.get_gwp_asan_metadata();
}
} else if (g_callbacks.get_process_info) {
process_info = g_callbacks.get_process_info();
}
// If sival_int is ~0, it means that the fallback handler has been called
@ -524,7 +522,7 @@ static void debuggerd_signal_handler(int signal_number, siginfo_t* info, void* c
// This check might be racy if another thread sets NO_NEW_PRIVS, but this should be unlikely,
// you can only set NO_NEW_PRIVS to 1, and the effect should be at worst a single missing
// ANR trace.
debuggerd_fallback_handler(info, static_cast<ucontext_t*>(context), abort_message);
debuggerd_fallback_handler(info, static_cast<ucontext_t*>(context), process_info.abort_msg);
resend_signal(info);
return;
}
@ -543,10 +541,7 @@ static void debuggerd_signal_handler(int signal_number, siginfo_t* info, void* c
.pseudothread_tid = -1,
.siginfo = info,
.ucontext = context,
.abort_msg = reinterpret_cast<uintptr_t>(abort_message),
.fdsan_table = reinterpret_cast<uintptr_t>(android_fdsan_get_fd_table()),
.gwp_asan_state = reinterpret_cast<uintptr_t>(gwp_asan_state),
.gwp_asan_metadata = reinterpret_cast<uintptr_t>(gwp_asan_metadata),
.process_info = process_info,
};
// Set PR_SET_DUMPABLE to 1, so that crash_dump can ptrace us.

13
debuggerd/include/debuggerd/handler.h
View file

@ -33,13 +33,20 @@ struct AllocatorState;
struct AllocationMetadata;
}; // namespace gwp_asan
// When updating this data structure, CrashInfoDataDynamic and the code in
// ReadCrashInfo() must also be updated.
struct debugger_process_info {
void* abort_msg;
void* fdsan_table;
const gwp_asan::AllocatorState* gwp_asan_state;
const gwp_asan::AllocationMetadata* gwp_asan_metadata;
};
// These callbacks are called in a signal handler, and thus must be async signal safe.
// If null, the callbacks will not be called.
typedef struct {
struct abort_msg_t* (*get_abort_message)();
debugger_process_info (*get_process_info)();
void (*post_dump)();
const struct gwp_asan::AllocatorState* (*get_gwp_asan_state)();
const struct gwp_asan::AllocationMetadata* (*get_gwp_asan_metadata)();
} debuggerd_callbacks_t;
void debuggerd_init(debuggerd_callbacks_t* callbacks);

12
debuggerd/protocol.h
View file

@ -85,17 +85,14 @@ struct __attribute__((__packed__)) CrashInfoHeader {
uint32_t version;
};
struct __attribute__((__packed__)) CrashInfoDataV1 {
struct __attribute__((__packed__)) CrashInfoDataStatic {
siginfo_t siginfo;
ucontext_t ucontext;
uintptr_t abort_msg_address;
};
struct __attribute__((__packed__)) CrashInfoDataV2 : public CrashInfoDataV1 {
struct __attribute__((__packed__)) CrashInfoDataDynamic : public CrashInfoDataStatic {
uintptr_t fdsan_table_address;
};
struct __attribute__((__packed__)) CrashInfoDataV3 : public CrashInfoDataV2 {
uintptr_t gwp_asan_state;
uintptr_t gwp_asan_metadata;
};
@ -103,8 +100,7 @@ struct __attribute__((__packed__)) CrashInfoDataV3 : public CrashInfoDataV2 {
struct __attribute__((__packed__)) CrashInfo {
CrashInfoHeader header;
union {
CrashInfoDataV1 v1;
CrashInfoDataV2 v2;
CrashInfoDataV3 v3;
CrashInfoDataStatic s;
CrashInfoDataDynamic d;
} data;
};