Commit 46ddcb39 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

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: default avatarChristophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: default avatarSantosh Sivaraj <santosh@fossix.org>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4f88d7e6fda53b5f80a71040ab400242f6c8cb93.1566400889.git.christophe.leroy@c-s.fr
parent c4028fa2

arch/powerpc/mm/fault.c

+4 −2
Original line number Diff line number Diff line
@@ -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:

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