Merge "Add tool to save information from a process." am: 7c20a6cd7c
am: ca0cae76eb
Change-Id: I3889436557f3bacea854400470c06b2fdcefbaac
diff --git a/libunwindstack/Android.bp b/libunwindstack/Android.bp
index fad899f..133f3b9 100644
--- a/libunwindstack/Android.bp
+++ b/libunwindstack/Android.bp
@@ -215,6 +215,15 @@
],
}
+cc_binary {
+ name: "unwind_for_offline",
+ defaults: ["libunwindstack_tools"],
+
+ srcs: [
+ "tools/unwind_for_offline.cpp",
+ ],
+}
+
// Generates the elf data for use in the tests for .gnu_debugdata frames.
// Once these files are generated, use the xz command to compress the data.
cc_binary_host {
diff --git a/libunwindstack/Memory.cpp b/libunwindstack/Memory.cpp
index 1f3c6c3..285f879 100644
--- a/libunwindstack/Memory.cpp
+++ b/libunwindstack/Memory.cpp
@@ -35,10 +35,6 @@
namespace unwindstack {
static size_t ProcessVmRead(pid_t pid, uint64_t remote_src, void* dst, size_t len) {
- struct iovec dst_iov = {
- .iov_base = dst,
- .iov_len = len,
- };
// Split up the remote read across page boundaries.
// From the manpage:
@@ -49,39 +45,49 @@
// perform a partial transfer that splits a single iovec element.
constexpr size_t kMaxIovecs = 64;
struct iovec src_iovs[kMaxIovecs];
- size_t iovecs_used = 0;
uint64_t cur = remote_src;
+ size_t total_read = 0;
while (len > 0) {
- if (iovecs_used == kMaxIovecs) {
- errno = EINVAL;
- return 0;
+ struct iovec dst_iov = {
+ .iov_base = &reinterpret_cast<uint8_t*>(dst)[total_read], .iov_len = len,
+ };
+
+ size_t iovecs_used = 0;
+ while (len > 0) {
+ if (iovecs_used == kMaxIovecs) {
+ break;
+ }
+
+ // struct iovec uses void* for iov_base.
+ if (cur >= UINTPTR_MAX) {
+ errno = EFAULT;
+ return total_read;
+ }
+
+ src_iovs[iovecs_used].iov_base = reinterpret_cast<void*>(cur);
+
+ uintptr_t misalignment = cur & (getpagesize() - 1);
+ size_t iov_len = getpagesize() - misalignment;
+ iov_len = std::min(iov_len, len);
+
+ len -= iov_len;
+ if (__builtin_add_overflow(cur, iov_len, &cur)) {
+ errno = EFAULT;
+ return total_read;
+ }
+
+ src_iovs[iovecs_used].iov_len = iov_len;
+ ++iovecs_used;
}
- // struct iovec uses void* for iov_base.
- if (cur >= UINTPTR_MAX) {
- errno = EFAULT;
- return 0;
+ ssize_t rc = process_vm_readv(pid, &dst_iov, 1, src_iovs, iovecs_used, 0);
+ if (rc == -1) {
+ return total_read;
}
-
- src_iovs[iovecs_used].iov_base = reinterpret_cast<void*>(cur);
-
- uintptr_t misalignment = cur & (getpagesize() - 1);
- size_t iov_len = getpagesize() - misalignment;
- iov_len = std::min(iov_len, len);
-
- len -= iov_len;
- if (__builtin_add_overflow(cur, iov_len, &cur)) {
- errno = EFAULT;
- return 0;
- }
-
- src_iovs[iovecs_used].iov_len = iov_len;
- ++iovecs_used;
+ total_read += rc;
}
-
- ssize_t rc = process_vm_readv(pid, &dst_iov, 1, src_iovs, iovecs_used, 0);
- return rc == -1 ? 0 : rc;
+ return total_read;
}
static bool PtraceReadLong(pid_t pid, uint64_t addr, long* value) {
diff --git a/libunwindstack/tests/MemoryRemoteTest.cpp b/libunwindstack/tests/MemoryRemoteTest.cpp
index f5492a2..fb56e8a 100644
--- a/libunwindstack/tests/MemoryRemoteTest.cpp
+++ b/libunwindstack/tests/MemoryRemoteTest.cpp
@@ -79,6 +79,35 @@
ASSERT_TRUE(Detach(pid));
}
+TEST_F(MemoryRemoteTest, read_large) {
+ static constexpr size_t kTotalPages = 245;
+ std::vector<uint8_t> src(kTotalPages * getpagesize());
+ for (size_t i = 0; i < kTotalPages; i++) {
+ memset(&src[i * getpagesize()], i, getpagesize());
+ }
+
+ pid_t pid;
+ if ((pid = fork()) == 0) {
+ while (true)
+ ;
+ exit(1);
+ }
+ ASSERT_LT(0, pid);
+ TestScopedPidReaper reap(pid);
+
+ ASSERT_TRUE(Attach(pid));
+
+ MemoryRemote remote(pid);
+
+ std::vector<uint8_t> dst(kTotalPages * getpagesize());
+ ASSERT_TRUE(remote.ReadFully(reinterpret_cast<uint64_t>(src.data()), dst.data(), src.size()));
+ for (size_t i = 0; i < kTotalPages * getpagesize(); i++) {
+ ASSERT_EQ(i / getpagesize(), dst[i]) << "Failed at byte " << i;
+ }
+
+ ASSERT_TRUE(Detach(pid));
+}
+
TEST_F(MemoryRemoteTest, read_partial) {
char* mapping = static_cast<char*>(
mmap(nullptr, 4 * getpagesize(), PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0));
diff --git a/libunwindstack/tools/unwind_for_offline.cpp b/libunwindstack/tools/unwind_for_offline.cpp
new file mode 100644
index 0000000..d64ef8f
--- /dev/null
+++ b/libunwindstack/tools/unwind_for_offline.cpp
@@ -0,0 +1,262 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define _GNU_SOURCE 1
+#include <errno.h>
+#include <inttypes.h>
+#include <signal.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ptrace.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <algorithm>
+#include <memory>
+#include <string>
+#include <unordered_map>
+#include <vector>
+
+#include <unwindstack/Elf.h>
+#include <unwindstack/Maps.h>
+#include <unwindstack/Memory.h>
+#include <unwindstack/Regs.h>
+#include <unwindstack/Unwinder.h>
+
+#include <android-base/stringprintf.h>
+
+struct map_info_t {
+ uint64_t start;
+ uint64_t end;
+ uint64_t offset;
+ std::string name;
+};
+
+static bool Attach(pid_t pid) {
+ if (ptrace(PTRACE_ATTACH, pid, 0, 0) == -1) {
+ return false;
+ }
+
+ // Allow at least 1 second to attach properly.
+ for (size_t i = 0; i < 1000; i++) {
+ siginfo_t si;
+ if (ptrace(PTRACE_GETSIGINFO, pid, 0, &si) == 0) {
+ return true;
+ }
+ usleep(1000);
+ }
+ printf("%d: Failed to stop.\n", pid);
+ return false;
+}
+
+bool SaveRegs(unwindstack::Regs* regs) {
+ std::unique_ptr<FILE, decltype(&fclose)> fp(fopen("regs.txt", "w+"), &fclose);
+ if (fp == nullptr) {
+ printf("Failed to create file regs.txt.\n");
+ return false;
+ }
+ regs->IterateRegisters([&fp](const char* name, uint64_t value) {
+ fprintf(fp.get(), "%s: %" PRIx64 "\n", name, value);
+ });
+
+ return true;
+}
+
+bool SaveStack(pid_t pid, uint64_t sp_start, uint64_t sp_end) {
+ std::unique_ptr<FILE, decltype(&fclose)> fp(fopen("stack.data", "w+"), &fclose);
+ if (fp == nullptr) {
+ printf("Failed to create stack.data.\n");
+ return false;
+ }
+
+ size_t bytes = fwrite(&sp_start, 1, sizeof(sp_start), fp.get());
+ if (bytes != sizeof(sp_start)) {
+ perror("Failed to write all data.");
+ return false;
+ }
+
+ std::vector<uint8_t> buffer(sp_end - sp_start);
+ auto process_memory = unwindstack::Memory::CreateProcessMemory(pid);
+ if (!process_memory->Read(sp_start, buffer.data(), buffer.size())) {
+ printf("Unable to read stack data.\n");
+ return false;
+ }
+
+ bytes = fwrite(buffer.data(), 1, buffer.size(), fp.get());
+ if (bytes != buffer.size()) {
+ printf("Failed to write all stack data: stack size %zu, written %zu\n", buffer.size(), bytes);
+ return 1;
+ }
+
+ return true;
+}
+
+bool CreateElfFromMemory(std::shared_ptr<unwindstack::Memory>& memory, map_info_t* info) {
+ std::string cur_name;
+ if (info->name.empty()) {
+ cur_name = android::base::StringPrintf("anonymous:%" PRIx64, info->start);
+ } else {
+ cur_name = basename(info->name.c_str());
+ cur_name = android::base::StringPrintf("%s:%" PRIx64, basename(info->name.c_str()), info->start);
+ }
+
+ std::unique_ptr<FILE, decltype(&fclose)> output(fopen(cur_name.c_str(), "w+"), &fclose);
+ if (output == nullptr) {
+ printf("Cannot create %s\n", cur_name.c_str());
+ return false;
+ }
+ std::vector<uint8_t> buffer(info->end - info->start);
+ // If this is a mapped in file, it might not be possible to read the entire
+ // map, so read all that is readable.
+ size_t bytes = memory->Read(info->start, buffer.data(), buffer.size());
+ if (bytes == 0) {
+ printf("Cannot read data from address %" PRIx64 " length %zu\n", info->start, buffer.size());
+ return false;
+ }
+ size_t bytes_written = fwrite(buffer.data(), 1, bytes, output.get());
+ if (bytes_written != bytes) {
+ printf("Failed to write all data to file: bytes read %zu, written %zu\n", bytes, bytes_written);
+ return false;
+ }
+
+ // Replace the name with the new name.
+ info->name = cur_name;
+
+ return true;
+}
+
+bool CopyElfFromFile(map_info_t* info) {
+ std::unique_ptr<FILE, decltype(&fclose)> fp(fopen(info->name.c_str(), "r"), &fclose);
+ if (fp == nullptr) {
+ return false;
+ }
+
+ std::string cur_name = basename(info->name.c_str());
+ std::unique_ptr<FILE, decltype(&fclose)> output(fopen(cur_name.c_str(), "w+"), &fclose);
+ if (output == nullptr) {
+ printf("Cannot create file %s\n", cur_name.c_str());
+ return false;
+ }
+ std::vector<uint8_t> buffer(10000);
+ size_t bytes;
+ while ((bytes = fread(buffer.data(), 1, buffer.size(), fp.get())) > 0) {
+ size_t bytes_written = fwrite(buffer.data(), 1, bytes, output.get());
+ if (bytes_written != bytes) {
+ printf("Bytes written doesn't match bytes read: read %zu, written %zu\n", bytes,
+ bytes_written);
+ return false;
+ }
+ }
+
+ // Replace the name with the new name.
+ info->name = cur_name;
+
+ return true;
+}
+
+int SaveData(pid_t pid) {
+ unwindstack::Regs* regs = unwindstack::Regs::RemoteGet(pid);
+ if (regs == nullptr) {
+ printf("Unable to get remote reg data.\n");
+ return 1;
+ }
+
+ unwindstack::RemoteMaps maps(pid);
+ if (!maps.Parse()) {
+ printf("Unable to parse maps.\n");
+ return 1;
+ }
+
+ // Save the current state of the registers.
+ if (!SaveRegs(regs)) {
+ return 1;
+ }
+
+ // Do an unwind so we know how much of the stack to save, and what
+ // elf files are involved.
+ uint64_t sp = regs->sp();
+ auto process_memory = unwindstack::Memory::CreateProcessMemory(pid);
+ unwindstack::Unwinder unwinder(1024, &maps, regs, process_memory);
+ unwinder.Unwind();
+
+ std::unordered_map<uint64_t, map_info_t> maps_by_start;
+ uint64_t last_sp;
+ for (auto frame : unwinder.frames()) {
+ last_sp = frame.sp;
+ if (maps_by_start.count(frame.map_start) == 0) {
+ auto info = &maps_by_start[frame.map_start];
+ info->start = frame.map_start;
+ info->end = frame.map_end;
+ info->offset = frame.map_offset;
+ info->name = frame.map_name;
+ if (!CopyElfFromFile(info)) {
+ // Try to create the elf from memory, this will handle cases where
+ // the data only exists in memory such as vdso data on x86.
+ if (!CreateElfFromMemory(process_memory, info)) {
+ return 1;
+ }
+ }
+ }
+ }
+
+ if (!SaveStack(pid, sp, last_sp)) {
+ return 1;
+ }
+
+ std::vector<std::pair<uint64_t, map_info_t>> sorted_maps(maps_by_start.begin(),
+ maps_by_start.end());
+ std::sort(sorted_maps.begin(), sorted_maps.end(),
+ [](auto& a, auto& b) { return a.first < b.first; });
+
+ std::unique_ptr<FILE, decltype(&fclose)> fp(fopen("maps.txt", "w+"), &fclose);
+ if (fp == nullptr) {
+ printf("Failed to create maps.txt.\n");
+ return false;
+ }
+
+ for (auto& element : sorted_maps) {
+ map_info_t& map = element.second;
+ fprintf(fp.get(), "%" PRIx64 "-%" PRIx64 " r-xp %" PRIx64 " 00:00 0", map.start, map.end,
+ map.offset);
+ if (!map.name.empty()) {
+ fprintf(fp.get(), " %s", map.name.c_str());
+ }
+ fprintf(fp.get(), "\n");
+ }
+
+ return 0;
+}
+
+int main(int argc, char** argv) {
+ if (argc != 2) {
+ printf("Usage: unwind_for_offline <PID>\n");
+ return 1;
+ }
+
+ pid_t pid = atoi(argv[1]);
+ if (!Attach(pid)) {
+ printf("Failed to attach to pid %d: %s\n", pid, strerror(errno));
+ return 1;
+ }
+
+ int return_code = SaveData(pid);
+
+ ptrace(PTRACE_DETACH, pid, 0, 0);
+
+ return return_code;
+}