This is particularly a problem when the neighboring mapping is a
special mapping not readable from another process. For example:
7fff96aeb000-7fff96b0c000 rw-p 00000000 00:00 0 [stack]
7fff96b0c000-7fff96b0e000 r--p 00000000 00:00 0 [vvar]
[vvar] is a special mapping which makes some kernel data available
for virtual system calls. Attempting to read this region via the
/proc/<pid>/maps file returns an IO error which causes Crashpad to
abort capturing any of the thread's stack.
Neighboring mappings with empty names are eligible to be merged since
they result from changing permissions on existing named mappings.
Change-Id: I587bd2ec6f9759d284f1f9b1d93f2a44ddf61e92
Reviewed-on: https://chromium-review.googlesource.com/1072803
Reviewed-by: Scott Graham <scottmg@chromium.org>
Commit-Queue: Joshua Peraza <jperaza@chromium.org>
This change:
1. Updates the broker's memory reading protocol to enable short reads.
2. Updates Ptracer to allow short reads.
3. Updates the broker to allow reading from a memory file.
4. Updates the broker's default file root to be "/proc/[pid]/".
5. Adds PtraceConnection::Memory() to produce a suitable memory reader
for a connection type.
Bug: crashpad:30
Change-Id: I8c004016065d981acd1fa74ad1b8e51ce07c7c85
Reviewed-on: https://chromium-review.googlesource.com/991455
Reviewed-by: Mark Mentovai <mark@chromium.org>
Commit-Queue: Joshua Peraza <jperaza@chromium.org>
Some files, such as /proc/[pid]/maps, may not be accessible to the
handler. This enables the handler access to the contents of those files
via the broker.
This change reads maps and auxv using ReadFileContents.
Bug: crashpad:30
Change-Id: Ia19b498bae473c616ea794ab51c3f22afd5795be
Reviewed-on: https://chromium-review.googlesource.com/989406
Reviewed-by: Mark Mentovai <mark@chromium.org>
