Re: [PATCH] powerpc/mm: tell if a bad page fault on data is read or write.
From: Santosh Sivaraj <hidden>
Date: 2019-08-26 05:36:02
Also in:
lkml
Christophe Leroy [off-list ref] writes:
DSISR has a bit to tell if the fault is due to a read or a write. Display it. Signed-off-by: Christophe Leroy <redacted>
Reviewed-by: Santosh Sivaraj <redacted>
quoted hunk ↗ jump to hunk
--- arch/powerpc/mm/fault.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 8432c281de92..b5047f9b5dec 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c@@ -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:-- 2.13.3