RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-14 17:34:59 +00:00
Code Issues Activity Actions

Kernel: Remove heuristics for detecting malformed malloc memory access

Browse source 
I never saw these kind of messages in any debug session I had, and it
helps us to remove an include to LibC/mallocdefs.h file.
This commit is contained in:
Liav A 2023-02-26 18:29:42 +02:00 • committed by Andrew Kaster
parent 9da09e4fd3
commit 5416a37fde
1 changed files with 0 additions and 7 deletions
Download patch file Download diff file Expand all files Collapse all files

7
Kernel/Arch/PageFault.cpp
View file

@ -11,7 +11,6 @@
#include <Kernel/Arch/SafeMem.h> #include <Kernel/Arch/SafeMem.h>
#include <Kernel/PerformanceManager.h> #include <Kernel/PerformanceManager.h>
#include <Kernel/Thread.h> #include <Kernel/Thread.h>
#include <LibC/mallocdefs.h>
namespace Kernel { namespace Kernel {
@ -82,16 +81,10 @@ void PageFault::handle(RegisterState& regs)
is_instruction_fetch() ? "instruction fetch / " : "", is_instruction_fetch() ? "instruction fetch / " : "",
is_write() ? "write to" : "read from", is_write() ? "write to" : "read from",
VirtualAddress(fault_address)); VirtualAddress(fault_address));
constexpr FlatPtr malloc_scrub_pattern = explode_byte(MALLOC_SCRUB_BYTE);
constexpr FlatPtr free_scrub_pattern = explode_byte(FREE_SCRUB_BYTE);
constexpr FlatPtr kmalloc_scrub_pattern = explode_byte(KMALLOC_SCRUB_BYTE); constexpr FlatPtr kmalloc_scrub_pattern = explode_byte(KMALLOC_SCRUB_BYTE);
constexpr FlatPtr kfree_scrub_pattern = explode_byte(KFREE_SCRUB_BYTE); constexpr FlatPtr kfree_scrub_pattern = explode_byte(KFREE_SCRUB_BYTE);
if (response == PageFaultResponse::BusError) { if (response == PageFaultResponse::BusError) {
dbgln("Note: Address {} is an access to an undefined memory range of an Inode-backed VMObject", VirtualAddress(fault_address)); dbgln("Note: Address {} is an access to an undefined memory range of an Inode-backed VMObject", VirtualAddress(fault_address));
} else if ((fault_address & 0xffff0000) == (malloc_scrub_pattern & 0xffff0000)) {
dbgln("Note: Address {} looks like it may be uninitialized malloc() memory", VirtualAddress(fault_address));
} else if ((fault_address & 0xffff0000) == (free_scrub_pattern & 0xffff0000)) {
dbgln("Note: Address {} looks like it may be recently free()'d memory", VirtualAddress(fault_address));
} else if ((fault_address & 0xffff0000) == (kmalloc_scrub_pattern & 0xffff0000)) { } else if ((fault_address & 0xffff0000) == (kmalloc_scrub_pattern & 0xffff0000)) {
dbgln("Note: Address {} looks like it may be uninitialized kmalloc() memory", VirtualAddress(fault_address)); dbgln("Note: Address {} looks like it may be uninitialized kmalloc() memory", VirtualAddress(fault_address));
} else if ((fault_address & 0xffff0000) == (kfree_scrub_pattern & 0xffff0000)) { } else if ((fault_address & 0xffff0000) == (kfree_scrub_pattern & 0xffff0000)) {