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Update debuggerd for stack MTE.

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Two things need changing for debuggerd_test to pass.

 1. The seccomp policy needs to allow for PROT_MTE (0x20) in both
    mprotect() and mmap(). Stack MTE processes do a mprotect()/mmap() of
    the stack when launching a process.
 2. The fault address and stack pointer need to be untagged when trying
    to figure out the stack overflow cause.

Bug: 320448268
Bug: 292478827
Test: atest debuggerd_test --iterations=10
Change-Id: I56471c32ca40edffbb61b7547bdf2b85a6eb1ff7
This commit is contained in:
Mitch Phillips 2024-02-06 15:18:04 +01:00
parent 749e2e8e2d
commit bf2d6dd7d4
2 changed files with 7 additions and 2 deletions
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5
debuggerd/libdebuggerd/tombstone_proto.cpp
View file

@ -94,6 +94,11 @@ static Architecture get_arch() {
static std::optional<std::string> get_stack_overflow_cause(uint64_t fault_addr, uint64_t sp,
unwindstack::Maps* maps) {
// Under stack MTE the stack pointer and/or the fault address can be tagged.
// In order to calculate deltas between them, strip off the tags off both
// addresses.
fault_addr = untag_address(fault_addr);
sp = untag_address(sp);
static constexpr uint64_t kMaxDifferenceBytes = 256;
uint64_t difference;
if (sp >= fault_addr) {

4
debuggerd/seccomp_policy/crash_dump.arm64.policy
View file

@ -28,11 +28,11 @@ rt_sigaction: 1
rt_tgsigqueueinfo: 1
prctl: arg0 == PR_GET_NO_NEW_PRIVS || arg0 == 0x53564d41 || arg0 == PR_PAC_RESET_KEYS || arg0 == 56 || arg0 == 61
madvise: 1
mprotect: arg2 in 0x1|0x2
mprotect: arg2 in 0x1|0x2|0x20
munmap: 1
getuid: 1
fstat: 1
mmap: arg2 in 0x1|0x2
mmap: arg2 in 0x1|0x2|0x20
geteuid: 1
getgid: 1
getegid: 1