Changes to fix build warnings on newer versions of GCC, and a fix to not try to open certain mapped files.

A=ZhurunZ, Tristan Schmelcher
R=nealsid



git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@593 4c0a9323-5329-0410-9bdc-e9ce6186880e

src/client/linux/Makefile

@@ -37,7 +37,7 @@ LIB_C_SRC = ../../common/convert_UTF.c
 LIB_CC_OBJ=$(patsubst %.cc, $(OBJ_DIR)/%.o,$(LIB_CC_SRC))
 LIB_C_OBJ=$(patsubst %.c, $(OBJ_DIR)/%.o, $(LIB_C_SRC))
 
-DUMPER_HELPER_TEST_C_SRC=minidump_writer/linux_dumper_unittest_helper.c
+DUMPER_HELPER_TEST_C_SRC=minidump_writer/linux_dumper_unittest_helper.cc
 
 DUMPER_HELPER_TEST_C_OBJ=$(patsubst %.cc, $(OBJ_DIR)/%.o, \
 			   $(DUMPER_HELPER_TEST_C_SRC))

src/client/linux/crash_generation/crash_generation_client.cc

@@ -64,7 +64,8 @@ CrashGenerationClient::RequestDump(const void* blob, size_t blob_size)
   hdr->cmsg_level = SOL_SOCKET;
   hdr->cmsg_type = SCM_RIGHTS;
   hdr->cmsg_len = CMSG_LEN(sizeof(int));
-  *((int*) CMSG_DATA(hdr)) = fds[1];
+  int* p = reinterpret_cast<int*>(CMSG_DATA(hdr));
+  *p = fds[1];
 
   HANDLE_EINTR(sys_sendmsg(server_fd_, &msg, 0));
   sys_close(fds[1]);

src/client/linux/minidump_writer/linux_dumper.cc

@@ -59,6 +59,8 @@
 #include "common/linux/linux_libc_support.h"
 #include "common/linux/linux_syscall_support.h"
 
+static const char kMappedFileUnsafePrefix[] = "/dev/";
+
 // Suspend a thread by attaching to it.
 static bool SuspendThread(pid_t pid) {
   // This may fail if the thread has just died or debugged.
@@ -81,6 +83,17 @@ static bool ResumeThread(pid_t pid) {
   return sys_ptrace(PTRACE_DETACH, pid, NULL, NULL) >= 0;
 }
 
+inline static bool IsMappedFileOpenUnsafe(
+    const google_breakpad::MappingInfo* mapping) {
+  // It is unsafe to attempt to open a mapped file that lives under /dev,
+  // because the semantics of the open may be driver-specific so we'd risk
+  // hanging the crash dumper. And a file in /dev/ almost certainly has no
+  // ELF file identifier anyways.
+  return my_strncmp(mapping->name,
+                    kMappedFileUnsafePrefix,
+                    sizeof(kMappedFileUnsafePrefix) - 1) == 0;
+}
+
 namespace google_breakpad {
 
 LinuxDumper::LinuxDumper(int pid)
@@ -166,7 +179,11 @@ LinuxDumper::ElfFileIdentifierForMapping(unsigned int mapping_id,
                                          uint8_t identifier[sizeof(MDGUID)])
 {
   assert(mapping_id < mappings_.size());
+  my_memset(identifier, 0, sizeof(MDGUID));
   const MappingInfo* mapping = mappings_[mapping_id];
+  if (IsMappedFileOpenUnsafe(mapping)) {
+    return false;
+  }
   int fd = sys_open(mapping->name, O_RDONLY, 0);
   if (fd < 0)
     return false;