From 0b8226811f0340316e4b0b6c05342598f86e5cd1 Mon Sep 17 00:00:00 2001 From: Andreas Kling Date: Sun, 4 Apr 2021 20:11:54 +0200 Subject: 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. :^) --- Kernel/Arch/i386/CPU.cpp | 16 ++++++++++++++-- Kernel/Process.cpp | 5 +++++ Kernel/Process.h | 1 + 3 files changed, 20 insertions(+), 2 deletions(-) (limited to 'Kernel') diff --git a/Kernel/Arch/i386/CPU.cpp b/Kernel/Arch/i386/CPU.cpp index 5f3ecfc129..4a3dba9529 100644 --- a/Kernel/Arch/i386/CPU.cpp +++ b/Kernel/Arch/i386/CPU.cpp @@ -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 diff --git a/Kernel/Process.cpp b/Kernel/Process.cpp index 7899f5dacb..fb18f73796 100644 --- a/Kernel/Process.cpp +++ b/Kernel/Process.cpp @@ -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)); +} + } diff --git a/Kernel/Process.h b/Kernel/Process.h index b1e864817d..7848baa312 100644 --- a/Kernel/Process.h +++ b/Kernel/Process.h @@ -494,6 +494,7 @@ public: HashMap& coredump_metadata() { return m_coredump_metadata; } const HashMap& coredump_metadata() const { return m_coredump_metadata; } + void set_coredump_metadata(const String& key, String value); const NonnullRefPtrVector& threads_for_coredump(Badge) const { return m_threads_for_coredump; } -- cgit debian/1.2.3+git2.25.1-1-2-gaceb0