diff options
Diffstat (limited to 'arch/arm64/mm/fault.c')
| -rw-r--r-- | arch/arm64/mm/fault.c | 42 |
1 files changed, 35 insertions, 7 deletions
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index 2e339f0bd958..871c82ab0a30 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -10,6 +10,7 @@ #include <linux/acpi.h> #include <linux/bitfield.h> #include <linux/extable.h> +#include <linux/kfence.h> #include <linux/signal.h> #include <linux/mm.h> #include <linux/hardirq.h> @@ -302,12 +303,24 @@ static void die_kernel_fault(const char *msg, unsigned long addr, static void report_tag_fault(unsigned long addr, unsigned int esr, struct pt_regs *regs) { - bool is_write = ((esr & ESR_ELx_WNR) >> ESR_ELx_WNR_SHIFT) != 0; + static bool reported; + bool is_write; + + if (READ_ONCE(reported)) + return; + + /* + * This is used for KASAN tests and assumes that no MTE faults + * happened before running the tests. + */ + if (mte_report_once()) + WRITE_ONCE(reported, true); /* * SAS bits aren't set for all faults reported in EL1, so we can't * find out access size. */ + is_write = !!(esr & ESR_ELx_WNR); kasan_report(addr, 0, is_write, regs->pc); } #else @@ -319,12 +332,8 @@ static inline void report_tag_fault(unsigned long addr, unsigned int esr, static void do_tag_recovery(unsigned long addr, unsigned int esr, struct pt_regs *regs) { - static bool reported; - if (!READ_ONCE(reported)) { - report_tag_fault(addr, esr, regs); - WRITE_ONCE(reported, true); - } + report_tag_fault(addr, esr, regs); /* * Disable MTE Tag Checking on the local CPU for the current EL. @@ -381,6 +390,9 @@ static void __do_kernel_fault(unsigned long addr, unsigned int esr, } else if (addr < PAGE_SIZE) { msg = "NULL pointer dereference"; } else { + if (kfence_handle_page_fault(addr, esr & ESR_ELx_WNR, regs)) + return; + msg = "paging request"; } @@ -515,7 +527,7 @@ static int __kprobes do_page_fault(unsigned long far, unsigned int esr, const struct fault_info *inf; struct mm_struct *mm = current->mm; vm_fault_t fault; - unsigned long vm_flags = VM_ACCESS_FLAGS; + unsigned long vm_flags; unsigned int mm_flags = FAULT_FLAG_DEFAULT; unsigned long addr = untagged_addr(far); @@ -532,12 +544,28 @@ static int __kprobes do_page_fault(unsigned long far, unsigned int esr, if (user_mode(regs)) mm_flags |= FAULT_FLAG_USER; + /* + * vm_flags tells us what bits we must have in vma->vm_flags + * for the fault to be benign, __do_page_fault() would check + * vma->vm_flags & vm_flags and returns an error if the + * intersection is empty + */ if (is_el0_instruction_abort(esr)) { + /* It was exec fault */ vm_flags = VM_EXEC; mm_flags |= FAULT_FLAG_INSTRUCTION; } else if (is_write_abort(esr)) { + /* It was write fault */ vm_flags = VM_WRITE; mm_flags |= FAULT_FLAG_WRITE; + } else { + /* It was read fault */ + vm_flags = VM_READ; + /* Write implies read */ + vm_flags |= VM_WRITE; + /* If EPAN is absent then exec implies read */ + if (!cpus_have_const_cap(ARM64_HAS_EPAN)) + vm_flags |= VM_EXEC; } if (is_ttbr0_addr(addr) && is_el1_permission_fault(addr, esr, regs)) { |