Add an optional root prefix to Linux dumpers

The Linux dumpers use absolute paths for shared libraries referenced by
dumps, so they fail to locate them if the crash originated in a chroot.
This CL enables callers to specify a root prefix, which is prepended to
mapping paths before opening them.

BUG=chromium:591792
TEST=make check
Review URL: https://codereview.chromium.org/1761023002/

1 files changed, 10 insertions, 0 deletions

diff --git a/src/client/linux/minidump_writer/linux_core_dumper_unittest.cc b/src/client/linux/minidump_writer/linux_core_dumper_unittest.cc
index 8f6a423e..ae0c965b 100644
--- a/src/client/linux/minidump_writer/linux_core_dumper_unittest.cc
+++ b/src/client/linux/minidump_writer/linux_core_dumper_unittest.cc
@@ -39,6 +39,16 @@
 
 using namespace google_breakpad;
 
+TEST(LinuxCoreDumperTest, GetMappingAbsolutePath) {
+  const LinuxCoreDumper dumper(getpid(), "core", "/tmp", "/mnt/root");
+  const MappingInfo mapping = { 0, 0, 0, false, "/usr/lib/libc.so" };
+
+  char path[PATH_MAX];
+  dumper.GetMappingAbsolutePath(mapping, path);
+
+  EXPECT_STREQ("/mnt/root/usr/lib/libc.so", path);
+}
+
 TEST(LinuxCoreDumperTest, BuildProcPath) {
   const pid_t pid = getpid();
   const char procfs_path[] = "/procfs_copy";