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author | Florian Mayer <fmayer@google.com> | 2019-05-03 16:24:52 +0100 |
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committer | Florian Mayer <fmayer@google.com> | 2019-05-08 10:19:49 +0100 |
commit | 2a67b023bd615d43d2f9ee00c62049e11ea85379 (patch) | |
tree | 8d9090406b0497b6325ebf39c21fd98279f5ca77 | |
parent | 2a24f6bd5f61ee4e916f08a7a69b486891f12f44 (diff) | |
download | android_bionic-2a67b023bd615d43d2f9ee00c62049e11ea85379.tar.gz android_bionic-2a67b023bd615d43d2f9ee00c62049e11ea85379.tar.bz2 android_bionic-2a67b023bd615d43d2f9ee00c62049e11ea85379.zip |
Match maximum command line size for startup tracing.
Fix too small buffer for the startup property not accounting for the
prefix.
Bug: 131893397
This is a cherry-pick of f6d221eeed66c975fb05589a171fe4a05c0d35f7.
Change-Id: Iad2398bc09c61b1144430bcbef58e5a832b85b0a
Merged-In: Iad2398bc09c61b1144430bcbef58e5a832b85b0a
-rw-r--r-- | libc/bionic/malloc_heapprofd.cpp | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/libc/bionic/malloc_heapprofd.cpp b/libc/bionic/malloc_heapprofd.cpp index 2aeb9bfee..5d3735d27 100644 --- a/libc/bionic/malloc_heapprofd.cpp +++ b/libc/bionic/malloc_heapprofd.cpp @@ -143,22 +143,23 @@ static void MaybeInstallInitHeapprofdHook(int) { } } +constexpr char kHeapprofdProgramPropertyPrefix[] = "heapprofd.enable."; +constexpr size_t kHeapprofdProgramPropertyPrefixSize = sizeof(kHeapprofdProgramPropertyPrefix) - 1; +constexpr size_t kMaxCmdlineSize = 512; + static bool GetHeapprofdProgramProperty(char* data, size_t size) { - constexpr char prefix[] = "heapprofd.enable."; - // - 1 to skip nullbyte, which we will write later. - constexpr size_t prefix_size = sizeof(prefix) - 1; - if (size < prefix_size) { + if (size < kHeapprofdProgramPropertyPrefixSize) { error_log("%s: Overflow constructing heapprofd property", getprogname()); return false; } - memcpy(data, prefix, prefix_size); + memcpy(data, kHeapprofdProgramPropertyPrefix, kHeapprofdProgramPropertyPrefixSize); int fd = open("/proc/self/cmdline", O_RDONLY | O_CLOEXEC); if (fd == -1) { error_log("%s: Failed to open /proc/self/cmdline", getprogname()); return false; } - char cmdline[128]; + char cmdline[kMaxCmdlineSize]; ssize_t rd = read(fd, cmdline, sizeof(cmdline) - 1); close(fd); if (rd == -1) { @@ -167,7 +168,7 @@ static bool GetHeapprofdProgramProperty(char* data, size_t size) { } cmdline[rd] = '\0'; char* first_arg = static_cast<char*>(memchr(cmdline, '\0', rd)); - if (first_arg == nullptr || first_arg == cmdline + size - 1) { + if (first_arg == nullptr) { error_log("%s: Overflow reading cmdline", getprogname()); return false; } @@ -192,12 +193,12 @@ static bool GetHeapprofdProgramProperty(char* data, size_t size) { } size_t name_size = static_cast<size_t>(first_arg - start); - if (name_size >= size - prefix_size) { + if (name_size >= size - kHeapprofdProgramPropertyPrefixSize) { error_log("%s: overflow constructing heapprofd property.", getprogname()); return false; } // + 1 to also copy the trailing null byte. - memcpy(data + prefix_size, start, name_size + 1); + memcpy(data + kHeapprofdProgramPropertyPrefixSize, start, name_size + 1); return true; } @@ -213,7 +214,7 @@ bool HeapprofdShouldLoad() { return true; } - char program_property[128]; + char program_property[kHeapprofdProgramPropertyPrefixSize + kMaxCmdlineSize]; if (!GetHeapprofdProgramProperty(program_property, sizeof(program_property))) { return false; |