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Fix CalculateStackSize to behave properly when the main thread's stack is

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split up into multiple regions.

An older workaround relyied on known fixed stack locations and only filled in
the initial page of the stack if it was in a distinct region. The new approach
looks upwards for additional regions that appear to be part of the same stack.

With PIE on Lion, the stack no longer begins at a fixed address, so the older
workaround became ineffective.

BUG=247, chromium:94107
TEST=Stacks should run through to _main/start and then stop when examining
     Chrome on Lion with PIE and "slid" stacks.
Review URL: http://breakpad.appspot.com/300001

git-svn-id: http://google-breakpad.googlecode.com/svn/trunk@826 4c0a9323-5329-0410-9bdc-e9ce6186880e
This commit is contained in:
mark@chromium.org 2011-08-25 21:19:29 +00:00
parent 7b8b8632d3
commit 60a883212f
2 changed files with 30 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
src/client/mac/handler/minidump_generator.cc
View File

@ -255,37 +255,45 @@ size_t MinidumpGenerator::CalculateStackSize(mach_vm_address_t start_addr) {
kern_return_t result =
mach_vm_region_recurse(crashing_task_, &stack_region_base,
&stack_region_size, &nesting_level,
region_info,
&info_count);
region_info, &info_count);
if (start_addr < stack_region_base) {
// probably stack corruption, since mach_vm_region had to go
if (result != KERN_SUCCESS || start_addr < stack_region_base) {
// Failure or stack corruption, since mach_vm_region had to go
// higher in the process address space to find a valid region.
return 0;
}
if (((cpu_type_ & CPU_ARCH_ABI64) &&
(stack_region_base + stack_region_size) == TOP_OF_THREAD0_STACK_64BIT) ||
(!(cpu_type_ & CPU_ARCH_ABI64) &&
(stack_region_base + stack_region_size) == TOP_OF_THREAD0_STACK_32BIT)) {
// The stack for thread 0 needs to extend all the way to
// 0xc0000000 on 32 bit and 00007fff5fc00000 on 64bit. HOWEVER,
// for many processes, the stack is first created in one page
// below this, and is then later extended to a much larger size by
// creating a new VM region immediately below the initial page.
unsigned int tag = submap_info.user_tag;
// You can see this for yourself by running vmmap on a "hello,
// world" program
// If the user tag is VM_MEMORY_STACK, look for more readable regions with
// the same tag placed immediately above the computed stack region. Under
// some circumstances, the stack for thread 0 winds up broken up into
// multiple distinct abutting regions. This can happen for several reasons,
// including user code that calls setrlimit(RLIMIT_STACK, ...) or changes
// the access on stack pages by calling mprotect.
if (tag == VM_MEMORY_STACK) {
while (true) {
mach_vm_address_t next_region_base = stack_region_base +
stack_region_size;
mach_vm_address_t proposed_next_region_base = next_region_base;
mach_vm_size_t next_region_size;
nesting_level = 0;
mach_msg_type_number_t info_count = VM_REGION_SUBMAP_INFO_COUNT_64;
result = mach_vm_region_recurse(crashing_task_, &next_region_base,
&next_region_size, &nesting_level,
region_info, &info_count);
if (result != KERN_SUCCESS ||
next_region_base != proposed_next_region_base ||
submap_info.user_tag != tag ||
submap_info.protection & VM_PROT_READ == 0) {
break;
}
// Because of the above, we'll add 4k to include the original
// stack frame page.
// This method of finding the stack region needs to be done in
// a better way; the breakpad issue 247 is tracking this.
stack_region_size += 0x1000;
stack_region_size += next_region_size;
}
}
return result == KERN_SUCCESS ?
stack_region_base + stack_region_size - start_addr : 0;
return stack_region_base + stack_region_size - start_addr;
}
bool MinidumpGenerator::WriteStackFromStartAddress(

3
src/client/mac/handler/minidump_generator.h
View File

@ -51,9 +51,6 @@ namespace google_breakpad {
using std::string;
const u_int64_t TOP_OF_THREAD0_STACK_64BIT = 0x00007fff5fbff000LL;
const u_int32_t TOP_OF_THREAD0_STACK_32BIT = 0xbffff000;
// Use the REGISTER_FROM_THREADSTATE to access a register name from the
// breakpad_thread_state_t structure.
#if __DARWIN_UNIX03 || TARGET_CPU_X86_64 || TARGET_CPU_PPC64