From 9208fbc22400cca23358ce5daf66a09497e04ffe Mon Sep 17 00:00:00 2001 From: "primiano@chromium.org" Date: Tue, 10 Mar 2015 20:06:04 +0000 Subject: Microdump writer: stop using new/malloc in compromised context A recent change in the client-side microdump write (r1404) ended up introducing a call to new() to instantiate the line buffer that microdump uses to dump its lines. new/malloc is a luxury we cannot afford in a compromised context. This change switches the line buffer to be backed by the dumper page allocator, which on Linux/Android ends up requesting pages via mmap. Also, the microdump write bails out without crashing if the page allocator failed (crash during severe OOM). BUG=640 git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@1432 4c0a9323-5329-0410-9bdc-e9ce6186880e --- .../linux/microdump_writer/microdump_writer.cc | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) (limited to 'src/client/linux/microdump_writer') diff --git a/src/client/linux/microdump_writer/microdump_writer.cc b/src/client/linux/microdump_writer/microdump_writer.cc index 48016b02..e14f9754 100644 --- a/src/client/linux/microdump_writer/microdump_writer.cc +++ b/src/client/linux/microdump_writer/microdump_writer.cc @@ -41,7 +41,6 @@ #include "client/linux/log/log.h" #include "client/linux/minidump_writer/linux_ptrace_dumper.h" #include "common/linux/linux_libc_support.h" -#include "common/scoped_ptr.h" namespace { @@ -51,7 +50,6 @@ using google_breakpad::LinuxPtraceDumper; using google_breakpad::MappingInfo; using google_breakpad::MappingList; using google_breakpad::RawContextCPU; -using google_breakpad::scoped_array; using google_breakpad::SeccompUnwinder; using google_breakpad::ThreadInfo; using google_breakpad::UContextReader; @@ -69,14 +67,20 @@ class MicrodumpWriter { #endif dumper_(dumper), mapping_list_(mappings), - log_line_(new char[kLineBufferSize]) { - log_line_.get()[0] = '\0'; // Clear out the log line buffer. + log_line_(NULL) { + log_line_ = reinterpret_cast(Alloc(kLineBufferSize)); + if (log_line_) + log_line_[0] = '\0'; // Clear out the log line buffer. } ~MicrodumpWriter() { dumper_->ThreadsResume(); } bool Init() { - if (!dumper_->Init()) + // In the exceptional case where the system was out of memory and there + // wasn't even room to allocate the line buffer, bail out. There is nothing + // useful we can possibly achieve without the ability to Log. At least let's + // try to not crash. + if (!dumper_->Init() || !log_line_) return false; return dumper_->ThreadsSuspend(); } @@ -105,7 +109,7 @@ class MicrodumpWriter { // Stages the given string in the current line buffer. void LogAppend(const char* str) { - my_strlcat(log_line_.get(), str, kLineBufferSize); + my_strlcat(log_line_, str, kLineBufferSize); } // As above (required to take precedence over template specialization below). @@ -135,8 +139,8 @@ class MicrodumpWriter { // Writes out the current line buffer on the system log. void LogCommitLine() { - LogLine(log_line_.get()); - my_strlcpy(log_line_.get(), "", kLineBufferSize); + LogLine(log_line_); + my_strlcpy(log_line_, "", kLineBufferSize); } bool DumpOSInformation() { @@ -363,7 +367,7 @@ class MicrodumpWriter { #endif LinuxDumper* dumper_; const MappingList& mapping_list_; - scoped_array log_line_; + char* log_line_; }; } // namespace -- cgit v1.2.1