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-rw-r--r--src/common/linux/elf_core_dump_unittest.cc21
-rw-r--r--src/common/linux/file_id.cc2
-rw-r--r--src/common/linux/memory_mapped_file.cc28
-rw-r--r--src/common/linux/memory_mapped_file.h5
-rw-r--r--src/common/linux/memory_mapped_file_unittest.cc54
5 files changed, 77 insertions, 33 deletions
diff --git a/src/common/linux/elf_core_dump_unittest.cc b/src/common/linux/elf_core_dump_unittest.cc
index 63ecb2f3..9b41dcee 100644
--- a/src/common/linux/elf_core_dump_unittest.cc
+++ b/src/common/linux/elf_core_dump_unittest.cc
@@ -70,7 +70,7 @@ TEST(ElfCoreDumpTest, TestElfHeader) {
ElfCoreDump core;
ASSERT_TRUE(WriteFile(core_file, &header, sizeof(header) - 1));
- ASSERT_TRUE(mapped_core_file.Map(core_file));
+ ASSERT_TRUE(mapped_core_file.Map(core_file, 0));
core.SetContent(mapped_core_file.content());
EXPECT_FALSE(core.IsValid());
EXPECT_EQ(NULL, core.GetHeader());
@@ -80,49 +80,49 @@ TEST(ElfCoreDumpTest, TestElfHeader) {
EXPECT_FALSE(core.GetFirstNote().IsValid());
ASSERT_TRUE(WriteFile(core_file, &header, sizeof(header)));
- ASSERT_TRUE(mapped_core_file.Map(core_file));
+ ASSERT_TRUE(mapped_core_file.Map(core_file, 0));
core.SetContent(mapped_core_file.content());
EXPECT_FALSE(core.IsValid());
header.e_ident[0] = ELFMAG0;
ASSERT_TRUE(WriteFile(core_file, &header, sizeof(header)));
- ASSERT_TRUE(mapped_core_file.Map(core_file));
+ ASSERT_TRUE(mapped_core_file.Map(core_file, 0));
core.SetContent(mapped_core_file.content());
EXPECT_FALSE(core.IsValid());
header.e_ident[1] = ELFMAG1;
ASSERT_TRUE(WriteFile(core_file, &header, sizeof(header)));
- ASSERT_TRUE(mapped_core_file.Map(core_file));
+ ASSERT_TRUE(mapped_core_file.Map(core_file, 0));
core.SetContent(mapped_core_file.content());
EXPECT_FALSE(core.IsValid());
header.e_ident[2] = ELFMAG2;
ASSERT_TRUE(WriteFile(core_file, &header, sizeof(header)));
- ASSERT_TRUE(mapped_core_file.Map(core_file));
+ ASSERT_TRUE(mapped_core_file.Map(core_file, 0));
core.SetContent(mapped_core_file.content());
EXPECT_FALSE(core.IsValid());
header.e_ident[3] = ELFMAG3;
ASSERT_TRUE(WriteFile(core_file, &header, sizeof(header)));
- ASSERT_TRUE(mapped_core_file.Map(core_file));
+ ASSERT_TRUE(mapped_core_file.Map(core_file, 0));
core.SetContent(mapped_core_file.content());
EXPECT_FALSE(core.IsValid());
header.e_ident[4] = ElfCoreDump::kClass;
ASSERT_TRUE(WriteFile(core_file, &header, sizeof(header)));
- ASSERT_TRUE(mapped_core_file.Map(core_file));
+ ASSERT_TRUE(mapped_core_file.Map(core_file, 0));
core.SetContent(mapped_core_file.content());
EXPECT_FALSE(core.IsValid());
header.e_version = EV_CURRENT;
ASSERT_TRUE(WriteFile(core_file, &header, sizeof(header)));
- ASSERT_TRUE(mapped_core_file.Map(core_file));
+ ASSERT_TRUE(mapped_core_file.Map(core_file, 0));
core.SetContent(mapped_core_file.content());
EXPECT_FALSE(core.IsValid());
header.e_type = ET_CORE;
ASSERT_TRUE(WriteFile(core_file, &header, sizeof(header)));
- ASSERT_TRUE(mapped_core_file.Map(core_file));
+ ASSERT_TRUE(mapped_core_file.Map(core_file, 0));
core.SetContent(mapped_core_file.content());
EXPECT_TRUE(core.IsValid());
}
@@ -156,7 +156,8 @@ TEST(ElfCoreDumpTest, ValidCoreFile) {
#endif
MemoryMappedFile mapped_core_file;
- ASSERT_TRUE(mapped_core_file.Map(crash_generator.GetCoreFilePath().c_str()));
+ ASSERT_TRUE(
+ mapped_core_file.Map(crash_generator.GetCoreFilePath().c_str(), 0));
ElfCoreDump core;
core.SetContent(mapped_core_file.content());
diff --git a/src/common/linux/file_id.cc b/src/common/linux/file_id.cc
index dc74e9e0..00b37313 100644
--- a/src/common/linux/file_id.cc
+++ b/src/common/linux/file_id.cc
@@ -149,7 +149,7 @@ bool FileID::ElfFileIdentifierFromMappedFile(const void* base,
}
bool FileID::ElfFileIdentifier(uint8_t identifier[kMDGUIDSize]) {
- MemoryMappedFile mapped_file(path_.c_str());
+ MemoryMappedFile mapped_file(path_.c_str(), 0);
if (!mapped_file.data()) // Should probably check if size >= ElfW(Ehdr)?
return false;
diff --git a/src/common/linux/memory_mapped_file.cc b/src/common/linux/memory_mapped_file.cc
index 0f0fcb2b..064326bb 100644
--- a/src/common/linux/memory_mapped_file.cc
+++ b/src/common/linux/memory_mapped_file.cc
@@ -46,15 +46,15 @@ namespace google_breakpad {
MemoryMappedFile::MemoryMappedFile() {}
-MemoryMappedFile::MemoryMappedFile(const char* path) {
- Map(path);
+MemoryMappedFile::MemoryMappedFile(const char* path, size_t offset) {
+ Map(path, offset);
}
MemoryMappedFile::~MemoryMappedFile() {
Unmap();
}
-bool MemoryMappedFile::Map(const char* path) {
+bool MemoryMappedFile::Map(const char* path, size_t offset) {
Unmap();
int fd = sys_open(path, O_RDONLY, 0);
@@ -73,25 +73,33 @@ bool MemoryMappedFile::Map(const char* path) {
return false;
}
- // If the file size is zero, simply use an empty MemoryRange and return
- // true. Don't bother to call mmap() even though mmap() can handle an
- // empty file on some platforms.
- if (st.st_size == 0) {
+ // Strangely file size can be negative, but we check above that it is not.
+ size_t file_len = static_cast<size_t>(st.st_size);
+ // If the file does not extend beyond the offset, simply use an empty
+ // MemoryRange and return true. Don't bother to call mmap()
+ // even though mmap() can handle an empty file on some platforms.
+ if (offset >= file_len) {
sys_close(fd);
return true;
}
#if defined(__x86_64__) || defined(__aarch64__)
- void* data = sys_mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+ void* data = sys_mmap(NULL, file_len, PROT_READ, MAP_PRIVATE, fd, offset);
#else
- void* data = sys_mmap2(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+ if ((offset & 4095) != 0) {
+ // Not page aligned.
+ sys_close(fd);
+ return false;
+ }
+ void* data = sys_mmap2(
+ NULL, file_len, PROT_READ, MAP_PRIVATE, fd, offset >> 12);
#endif
sys_close(fd);
if (data == MAP_FAILED) {
return false;
}
- content_.Set(data, st.st_size);
+ content_.Set(data, file_len - offset);
return true;
}
diff --git a/src/common/linux/memory_mapped_file.h b/src/common/linux/memory_mapped_file.h
index 6abd5b0c..fa660cc9 100644
--- a/src/common/linux/memory_mapped_file.h
+++ b/src/common/linux/memory_mapped_file.h
@@ -33,6 +33,7 @@
#ifndef COMMON_LINUX_MEMORY_MAPPED_FILE_H_
#define COMMON_LINUX_MEMORY_MAPPED_FILE_H_
+#include <stddef.h>
#include "common/basictypes.h"
#include "common/memory_range.h"
@@ -47,7 +48,7 @@ class MemoryMappedFile {
// Constructor that calls Map() to map a file at |path| into memory.
// If Map() fails, the object behaves as if it is default constructed.
- explicit MemoryMappedFile(const char* path);
+ MemoryMappedFile(const char* path, size_t offset);
~MemoryMappedFile();
@@ -56,7 +57,7 @@ class MemoryMappedFile {
// success. Mapping an empty file will succeed but with data() and size()
// returning NULL and 0, respectively. An existing mapping is unmapped
// before a new mapping is created.
- bool Map(const char* path);
+ bool Map(const char* path, size_t offset);
// Unmaps the memory for the mapped file. It's a no-op if no file is
// mapped.
diff --git a/src/common/linux/memory_mapped_file_unittest.cc b/src/common/linux/memory_mapped_file_unittest.cc
index 4fa50cf9..fad59f40 100644
--- a/src/common/linux/memory_mapped_file_unittest.cc
+++ b/src/common/linux/memory_mapped_file_unittest.cc
@@ -71,12 +71,12 @@ TEST_F(MemoryMappedFileTest, UnmapWithoutMap) {
TEST_F(MemoryMappedFileTest, MapNonexistentFile) {
{
- MemoryMappedFile mapped_file("nonexistent-file");
+ MemoryMappedFile mapped_file("nonexistent-file", 0);
ExpectNoMappedData(mapped_file);
}
{
MemoryMappedFile mapped_file;
- EXPECT_FALSE(mapped_file.Map("nonexistent-file"));
+ EXPECT_FALSE(mapped_file.Map("nonexistent-file", 0));
ExpectNoMappedData(mapped_file);
}
}
@@ -87,12 +87,12 @@ TEST_F(MemoryMappedFileTest, MapEmptyFile) {
ASSERT_TRUE(WriteFile(test_file.c_str(), NULL, 0));
{
- MemoryMappedFile mapped_file(test_file.c_str());
+ MemoryMappedFile mapped_file(test_file.c_str(), 0);
ExpectNoMappedData(mapped_file);
}
{
MemoryMappedFile mapped_file;
- EXPECT_TRUE(mapped_file.Map(test_file.c_str()));
+ EXPECT_TRUE(mapped_file.Map(test_file.c_str(), 0));
ExpectNoMappedData(mapped_file);
}
}
@@ -109,7 +109,7 @@ TEST_F(MemoryMappedFileTest, MapNonEmptyFile) {
ASSERT_TRUE(WriteFile(test_file.c_str(), data, data_size));
{
- MemoryMappedFile mapped_file(test_file.c_str());
+ MemoryMappedFile mapped_file(test_file.c_str(), 0);
EXPECT_FALSE(mapped_file.content().IsEmpty());
EXPECT_TRUE(mapped_file.data() != NULL);
EXPECT_EQ(data_size, mapped_file.size());
@@ -117,7 +117,7 @@ TEST_F(MemoryMappedFileTest, MapNonEmptyFile) {
}
{
MemoryMappedFile mapped_file;
- EXPECT_TRUE(mapped_file.Map(test_file.c_str()));
+ EXPECT_TRUE(mapped_file.Map(test_file.c_str(), 0));
EXPECT_FALSE(mapped_file.content().IsEmpty());
EXPECT_TRUE(mapped_file.data() != NULL);
EXPECT_EQ(data_size, mapped_file.size());
@@ -145,13 +145,13 @@ TEST_F(MemoryMappedFileTest, RemapAfterMap) {
ASSERT_TRUE(WriteFile(test_file2.c_str(), data2, data2_size));
{
- MemoryMappedFile mapped_file(test_file1.c_str());
+ MemoryMappedFile mapped_file(test_file1.c_str(), 0);
EXPECT_FALSE(mapped_file.content().IsEmpty());
EXPECT_TRUE(mapped_file.data() != NULL);
EXPECT_EQ(data1_size, mapped_file.size());
EXPECT_EQ(0, memcmp(data1, mapped_file.data(), data1_size));
- mapped_file.Map(test_file2.c_str());
+ mapped_file.Map(test_file2.c_str(), 0);
EXPECT_FALSE(mapped_file.content().IsEmpty());
EXPECT_TRUE(mapped_file.data() != NULL);
EXPECT_EQ(data2_size, mapped_file.size());
@@ -159,16 +159,50 @@ TEST_F(MemoryMappedFileTest, RemapAfterMap) {
}
{
MemoryMappedFile mapped_file;
- EXPECT_TRUE(mapped_file.Map(test_file1.c_str()));
+ EXPECT_TRUE(mapped_file.Map(test_file1.c_str(), 0));
EXPECT_FALSE(mapped_file.content().IsEmpty());
EXPECT_TRUE(mapped_file.data() != NULL);
EXPECT_EQ(data1_size, mapped_file.size());
EXPECT_EQ(0, memcmp(data1, mapped_file.data(), data1_size));
- mapped_file.Map(test_file2.c_str());
+ mapped_file.Map(test_file2.c_str(), 0);
EXPECT_FALSE(mapped_file.content().IsEmpty());
EXPECT_TRUE(mapped_file.data() != NULL);
EXPECT_EQ(data2_size, mapped_file.size());
EXPECT_EQ(0, memcmp(data2, mapped_file.data(), data2_size));
}
}
+
+TEST_F(MemoryMappedFileTest, MapWithOffset) {
+ // Put more data in the test file this time. Offsets can only be
+ // done on page boundaries, so we need a two page file to test this.
+ const int page_size = 4096;
+ char data1[2 * page_size];
+ size_t data1_size = sizeof(data1);
+ for (size_t i = 0; i < data1_size; ++i) {
+ data1[i] = i & 0x7f;
+ }
+
+ AutoTempDir temp_dir;
+ string test_file1 = temp_dir.path() + "/test_file1";
+ ASSERT_TRUE(WriteFile(test_file1.c_str(), data1, data1_size));
+ {
+ MemoryMappedFile mapped_file(test_file1.c_str(), page_size);
+ EXPECT_FALSE(mapped_file.content().IsEmpty());
+ EXPECT_TRUE(mapped_file.data() != NULL);
+ EXPECT_EQ(data1_size - page_size, mapped_file.size());
+ EXPECT_EQ(
+ 0,
+ memcmp(data1 + page_size, mapped_file.data(), data1_size - page_size));
+ }
+ {
+ MemoryMappedFile mapped_file;
+ mapped_file.Map(test_file1.c_str(), page_size);
+ EXPECT_FALSE(mapped_file.content().IsEmpty());
+ EXPECT_TRUE(mapped_file.data() != NULL);
+ EXPECT_EQ(data1_size - page_size, mapped_file.size());
+ EXPECT_EQ(
+ 0,
+ memcmp(data1 + page_size, mapped_file.data(), data1_size - page_size));
+ }
+}
generated by cgit v1.2.1 (git 2.18.0) at 2024-06-15 02:44:42 +0000