Kernel+CrashReporter: Add metadata about page faults to crash reports

Crash reports for page faults now tell you what kind of memory access
failed and where. :^)
This commit is contained in:
Andreas Kling 2021-04-04 20:11:54 +02:00
parent e238435c4f
commit 0b8226811f
Notes: sideshowbarker 2024-07-18 20:48:01 +09:00
4 changed files with 27 additions and 2 deletions

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@ -284,7 +284,8 @@ void page_fault_handler(TrapFrame* trap)
PANIC("Attempt to access UNMAP_AFTER_INIT section");
}
auto response = MM.handle_page_fault(PageFault(regs.exception_code, VirtualAddress(fault_address)));
PageFault fault { regs.exception_code, VirtualAddress { fault_address } };
auto response = MM.handle_page_fault(fault);
if (response == PageFaultResponse::ShouldCrash || response == PageFaultResponse::OutOfMemory) {
if (faulted_in_kernel && handle_safe_access_fault(regs, fault_address)) {
@ -328,6 +329,18 @@ void page_fault_handler(TrapFrame* trap)
dbgln("Note: Address {} looks like a possible nullptr dereference", VirtualAddress(fault_address));
}
auto& current_process = current_thread->process();
if (current_process.is_user_process()) {
current_process.set_coredump_metadata("fault_address", String::formatted("{:p}", fault_address));
current_process.set_coredump_metadata("fault_type", fault.type() == PageFault::Type::PageNotPresent ? "NotPresent" : "ProtectionViolation");
String fault_access;
if (fault.is_instruction_fetch())
fault_access = "Execute";
else
fault_access = fault.access() == PageFault::Access::Read ? "Read" : "Write";
current_process.set_coredump_metadata("fault_access", fault_access);
}
handle_crash(regs, "Page Fault", SIGSEGV, response == PageFaultResponse::OutOfMemory);
} else if (response == PageFaultResponse::Continue) {
#if PAGE_FAULT_DEBUG
@ -2397,7 +2410,6 @@ void copy_ptrace_registers_into_kernel_registers(RegisterState& kernel_regs, con
kernel_regs.eip = ptrace_regs.eip;
kernel_regs.eflags = (kernel_regs.eflags & ~safe_eflags_mask) | (ptrace_regs.eflags & safe_eflags_mask);
}
}
#ifdef DEBUG

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@ -727,4 +727,9 @@ void Process::set_dumpable(bool dumpable)
m_dumpable = dumpable;
}
void Process::set_coredump_metadata(const String& key, String value)
{
m_coredump_metadata.set(key, move(value));
}
}

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@ -494,6 +494,7 @@ public:
HashMap<String, String>& coredump_metadata() { return m_coredump_metadata; }
const HashMap<String, String>& coredump_metadata() const { return m_coredump_metadata; }
void set_coredump_metadata(const String& key, String value);
const NonnullRefPtrVector<Thread>& threads_for_coredump(Badge<CoreDump>) const { return m_threads_for_coredump; }

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@ -79,6 +79,13 @@ static TitleAndText build_backtrace(const CoreDump::Reader& coredump, const ELF:
else if (metadata.contains("pledge_violation"))
prepend_metadata("pledge_violation", "Has not pledged {}");
auto fault_address = metadata.get("fault_address");
auto fault_type = metadata.get("fault_type");
auto fault_access = metadata.get("fault_access");
if (fault_address.has_value() && fault_type.has_value() && fault_access.has_value()) {
builder.appendff("{} fault on {} at address {}\n\n", fault_type.value(), fault_access.value(), fault_address.value());
}
auto first_entry = true;
for (auto& entry : backtrace.entries()) {
if (first_entry)