arm64: mm: print out correct page table entries
When we take a fault that can't be handled, we print out the page table
entries associated with the faulting address. In some cases we currently
print out the wrong entries. For a faulting TTBR1 address, we sometimes
print out TTBR0 table entries instead, and for a faulting TTBR0 address
we sometimes print out TTBR1 table entries. Fix this by choosing the
tables based on the faulting address.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
[will: zero-extend addrs to 64-bit, don't walk swapper w/ TTBR0 addr]
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c
index c3f2b10..9d27b17 100644
--- a/arch/arm64/mm/fault.c
+++ b/arch/arm64/mm/fault.c
@@ -80,18 +80,33 @@ static inline int notify_page_fault(struct pt_regs *regs, unsigned int esr)
#endif
/*
- * Dump out the page tables associated with 'addr' in mm 'mm'.
+ * Dump out the page tables associated with 'addr' in the currently active mm.
*/
-void show_pte(struct mm_struct *mm, unsigned long addr)
+void show_pte(unsigned long addr)
{
+ struct mm_struct *mm;
pgd_t *pgd;
- if (!mm)
+ if (addr < TASK_SIZE) {
+ /* TTBR0 */
+ mm = current->active_mm;
+ if (mm == &init_mm) {
+ pr_alert("[%016lx] user address but active_mm is swapper\n",
+ addr);
+ return;
+ }
+ } else if (addr >= VA_START) {
+ /* TTBR1 */
mm = &init_mm;
+ } else {
+ pr_alert("[%016lx] address between user and kernel address ranges\n",
+ addr);
+ return;
+ }
pr_alert("pgd = %p\n", mm->pgd);
pgd = pgd_offset(mm, addr);
- pr_alert("[%08lx] *pgd=%016llx", addr, pgd_val(*pgd));
+ pr_alert("[%016lx] *pgd=%016llx", addr, pgd_val(*pgd));
do {
pud_t *pud;
@@ -196,8 +211,8 @@ static inline bool is_permission_fault(unsigned int esr, struct pt_regs *regs,
/*
* The kernel tried to access some page that wasn't present.
*/
-static void __do_kernel_fault(struct mm_struct *mm, unsigned long addr,
- unsigned int esr, struct pt_regs *regs)
+static void __do_kernel_fault(unsigned long addr, unsigned int esr,
+ struct pt_regs *regs)
{
const char *msg;
@@ -227,7 +242,7 @@ static void __do_kernel_fault(struct mm_struct *mm, unsigned long addr,
pr_alert("Unable to handle kernel %s at virtual address %08lx\n", msg,
addr);
- show_pte(mm, addr);
+ show_pte(addr);
die("Oops", regs, esr);
bust_spinlocks(0);
do_exit(SIGKILL);
@@ -249,7 +264,7 @@ static void __do_user_fault(struct task_struct *tsk, unsigned long addr,
pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x\n",
tsk->comm, task_pid_nr(tsk), inf->name, sig,
addr, esr);
- show_pte(tsk->mm, addr);
+ show_pte(addr);
__show_regs(regs);
}
@@ -265,7 +280,6 @@ static void __do_user_fault(struct task_struct *tsk, unsigned long addr,
static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs)
{
struct task_struct *tsk = current;
- struct mm_struct *mm = tsk->active_mm;
const struct fault_info *inf;
/*
@@ -276,7 +290,7 @@ static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *re
inf = esr_to_fault_info(esr);
__do_user_fault(tsk, addr, esr, inf->sig, inf->code, regs);
} else
- __do_kernel_fault(mm, addr, esr, regs);
+ __do_kernel_fault(addr, esr, regs);
}
#define VM_FAULT_BADMAP 0x010000
@@ -475,7 +489,7 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr,
return 0;
no_context:
- __do_kernel_fault(mm, addr, esr, regs);
+ __do_kernel_fault(addr, esr, regs);
return 0;
}