From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: [PATCH] powerpc/mm: tell if a bad page fault on data is read or write.
Date: Wed, 21 Aug 2019 15:21:55 +0000 (UTC) [thread overview]
Message-ID: <4f88d7e6fda53b5f80a71040ab400242f6c8cb93.1566400889.git.christophe.leroy@c-s.fr> (raw)
DSISR 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>
---
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
next reply other threads:[~2019-08-21 15:24 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-21 15:21 Christophe Leroy [this message]
2019-08-26 5:35 ` [PATCH] powerpc/mm: tell if a bad page fault on data is read or write Santosh Sivaraj
2019-08-29 12:14 ` Michael Ellerman
2019-08-29 12:59 ` Christophe Leroy
2019-08-30 7:41 ` Christophe Leroy
2019-11-25 10:46 ` Michael Ellerman
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