The main motivation for this change is to handle very large stack
traces, normally the result of infinite recursion. This part is
actually fairly simple, relaxing a few self-imposed limits on how
many frames we can unwind and the max size for stack memory.
Relaxing these limits requires stricter and more consistent checks for
stack unwinding. There are a number of unwinding invariants that apply
to all the platforms:
1. stack pointer (and frame pointer) must be within the stack memory
(frame pointer, if preset, must point to the right frame too)
2. unwinding must monotonically increase SP
(except for the first frame unwind, this must be a strict increase)
3. Instruction pointer (return address) must point to a valid location
4. stack pointer (and frame pointer) must be appropriately aligned
This change is focused on 2), which is enough to guarantee that the
unwinding doesn't get stuck in an infinite loop.
1) is implicitly validated part of accessing the stack memory
(explicit checks might be nice though).
4) is ABI specific and while it may be valuable in catching suspicious
frames is not in the scope of this change.
3) is also an interesting check but thanks to just-in-time compilation
it's more complex than just calling
StackWalker::InstructionAddressSeemsValid()
and we don't want to drop parts of the callstack due to an overly
conservative check.
Bug: chromium:735989
Change-Id: I9aaba77c7fd028942d77c87d51b5e6f94e136ddd
Reviewed-on: https://chromium-review.googlesource.com/563771
Reviewed-by: Mark Mentovai <mark@chromium.org>
Reviewed-by: Ivan Penkov <ivanpe@chromium.org>
We've gotten mixed advice from the lawyery types about whether this
matters. But it's easy enough to do.
a=jimblandy, r=nealsid
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@517 4c0a9323-5329-0410-9bdc-e9ce6186880e
At the moment, the StackWalker GetCallerFrame member function expects
a vector of WindowsFrameInfo structures, even though WindowsFrameInfo
is only used or useful on one one implementation (StackWalkerX86).
This patch changes StackWalker::GetCallerFrame to no longer expect the
WindowsFrameInfo structures, and changes all implementations to match.
In particular, StackWalkerX86 is changed to find the WindowsFrameInfo
data itself, and store a pointer to whatever it got in the StackFrame
object itself (which is really a StackFrameX86).
To allow GetCallerFrame implementations to look up stack walking data,
StackWalker::resolver_ needs to be made protected, not private.
a=jimblandy, r=mmentovai
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@491 4c0a9323-5329-0410-9bdc-e9ce6186880e
Also, rename stack_frame_info.h to windows_frame_info.h.
If it seems odd to have functions like FillSourceLineInfo returning
Windows-specific data structures... well, it is! This patch just makes
it more obvious what's going on.
a=jimblandy, r=nealsid
git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@471 4c0a9323-5329-0410-9bdc-e9ce6186880e
