powerpc/mm: Show if a bad page fault on data is read or write.

DSISR (or ESR on some CPUs) has a bit to tell if the fault is due to a
read or a write.

Display it.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Santosh Sivaraj <santosh@fossix.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4f88d7e6fda53b5f80a71040ab400242f6c8cb93.1566400889.git.christophe.leroy@c-s.fr
This commit is contained in:
Christophe Leroy 2019-08-21 15:21:55 +00:00 committed by Michael Ellerman
parent c4028fa2da
commit 46ddcb3950

View file

@ -645,6 +645,7 @@ NOKPROBE_SYMBOL(do_page_fault);
void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
{
const struct exception_table_entry *entry;
int is_write = page_fault_is_write(regs->dsisr);
/* Are we prepared to handle this fault? */
if ((entry = search_exception_tables(regs->nip)) != NULL) {
@ -658,9 +659,10 @@ void bad_page_fault(struct pt_regs *regs, unsigned long address, int sig)
case 0x300:
case 0x380:
case 0xe00:
pr_alert("BUG: %s at 0x%08lx\n",
pr_alert("BUG: %s on %s at 0x%08lx\n",
regs->dar < PAGE_SIZE ? "Kernel NULL pointer dereference" :
"Unable to handle kernel data access", regs->dar);
"Unable to handle kernel data access",
is_write ? "write" : "read", regs->dar);
break;
case 0x400:
case 0x480: