From: Santosh Sivaraj <santosh@fossix.org>
To: Christophe Leroy <christophe.leroy@c-s.fr>,
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: Re: [PATCH] powerpc/mm: tell if a bad page fault on data is read or write.
Date: Mon, 26 Aug 2019 11:05:56 +0530 [thread overview]
Message-ID: <87k1b0ij43.fsf@santosiv.in.ibm.com> (raw)
In-Reply-To: <4f88d7e6fda53b5f80a71040ab400242f6c8cb93.1566400889.git.christophe.leroy@c-s.fr>
Christophe Leroy <christophe.leroy@c-s.fr> 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 <christophe.leroy@c-s.fr>
Reviewed-by: Santosh Sivaraj <santosh@fossix.org>
> ---
> 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 prev parent reply other threads:[~2019-08-26 5:36 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-21 15:21 [PATCH] powerpc/mm: tell if a bad page fault on data is read or write Christophe Leroy
2019-08-26 5:35 ` Santosh Sivaraj [this message]
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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