From: He Zhe <[email protected]>
setup_io_tlb_npages does not check input argument before passing it
to isdigit. The argument would be a NULL pointer if "swiotlb", without
its value, is set in command line and thus causes the following panic.
PANIC: early exception 0xe3 IP 10:ffffffffbb9b8e9f error 0 cr2 0x0
[ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc3-yocto-standard+ #9
[ 0.000000] RIP: 0010:setup_io_tlb_npages+0xf/0x95
...
[ 0.000000] Call Trace:
[ 0.000000] do_early_param+0x57/0x8e
[ 0.000000] parse_args+0x208/0x320
[ 0.000000] ? rdinit_setup+0x30/0x30
[ 0.000000] parse_early_options+0x29/0x2d
[ 0.000000] ? rdinit_setup+0x30/0x30
[ 0.000000] parse_early_param+0x36/0x4d
[ 0.000000] setup_arch+0x336/0x99e
[ 0.000000] start_kernel+0x6f/0x4e6
[ 0.000000] x86_64_start_reservations+0x24/0x26
[ 0.000000] x86_64_start_kernel+0x6f/0x72
[ 0.000000] secondary_startup_64+0xa4/0xb0
This patch adds a check to prevent the panic and sets it for 4MB by default.
Signed-off-by: He Zhe <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: He Zhe <[email protected]>
---
v2: Set swiotlb for 4MB by default
kernel/dma/swiotlb.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 045930e..0e18cd4 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -58,6 +58,9 @@
*/
#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
+#define IO_TLB_DEFAULT_MB 4
+#define IO_TLB_DEFAULT_SLABS ((IO_TLB_DEFAULT_MB<<20) >> IO_TLB_SHIFT)
+
enum swiotlb_force swiotlb_force;
/*
@@ -103,6 +106,14 @@ static int late_alloc;
static int __init
setup_io_tlb_npages(char *str)
{
+ if (!str) {
+ pr_err("No value provided for swiotlb, "
+ "set it to %d slabs for %dMB by default.\n",
+ IO_TLB_DEFAULT_SLABS, IO_TLB_DEFAULT_MB);
+ io_tlb_nslabs = IO_TLB_DEFAULT_SLABS;
+ return 0;
+ }
+
if (isdigit(*str)) {
io_tlb_nslabs = simple_strtoul(str, &str, 0);
/* avoid tail segment of size < IO_TLB_SEGSIZE */
--
2.7.4
Kindly ping.
Zhe
On 12/3/18 6:22 PM, [email protected] wrote:
> From: He Zhe <[email protected]>
>
> setup_io_tlb_npages does not check input argument before passing it
> to isdigit. The argument would be a NULL pointer if "swiotlb", without
> its value, is set in command line and thus causes the following panic.
>
> PANIC: early exception 0xe3 IP 10:ffffffffbb9b8e9f error 0 cr2 0x0
> [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc3-yocto-standard+ #9
> [ 0.000000] RIP: 0010:setup_io_tlb_npages+0xf/0x95
> ...
> [ 0.000000] Call Trace:
> [ 0.000000] do_early_param+0x57/0x8e
> [ 0.000000] parse_args+0x208/0x320
> [ 0.000000] ? rdinit_setup+0x30/0x30
> [ 0.000000] parse_early_options+0x29/0x2d
> [ 0.000000] ? rdinit_setup+0x30/0x30
> [ 0.000000] parse_early_param+0x36/0x4d
> [ 0.000000] setup_arch+0x336/0x99e
> [ 0.000000] start_kernel+0x6f/0x4e6
> [ 0.000000] x86_64_start_reservations+0x24/0x26
> [ 0.000000] x86_64_start_kernel+0x6f/0x72
> [ 0.000000] secondary_startup_64+0xa4/0xb0
>
> This patch adds a check to prevent the panic and sets it for 4MB by default.
>
> Signed-off-by: He Zhe <[email protected]>
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
> Cc: [email protected]
>
> Signed-off-by: He Zhe <[email protected]>
> ---
> v2: Set swiotlb for 4MB by default
>
> kernel/dma/swiotlb.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
> index 045930e..0e18cd4 100644
> --- a/kernel/dma/swiotlb.c
> +++ b/kernel/dma/swiotlb.c
> @@ -58,6 +58,9 @@
> */
> #define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
>
> +#define IO_TLB_DEFAULT_MB 4
> +#define IO_TLB_DEFAULT_SLABS ((IO_TLB_DEFAULT_MB<<20) >> IO_TLB_SHIFT)
> +
> enum swiotlb_force swiotlb_force;
>
> /*
> @@ -103,6 +106,14 @@ static int late_alloc;
> static int __init
> setup_io_tlb_npages(char *str)
> {
> + if (!str) {
> + pr_err("No value provided for swiotlb, "
> + "set it to %d slabs for %dMB by default.\n",
> + IO_TLB_DEFAULT_SLABS, IO_TLB_DEFAULT_MB);
> + io_tlb_nslabs = IO_TLB_DEFAULT_SLABS;
> + return 0;
> + }
> +
> if (isdigit(*str)) {
> io_tlb_nslabs = simple_strtoul(str, &str, 0);
> /* avoid tail segment of size < IO_TLB_SEGSIZE */
On Mon, Jan 07, 2019 at 04:46:51PM +0800, He Zhe wrote:
> Kindly ping.
Konrad, I'll pick this up through the DMA mapping tree unless you
protest in the next few days.
On 1/11/19 1:27 AM, Konrad Rzeszutek Wilk wrote:
> Let's skip it. There was another patch that would allocate a default 4MB size if it there was an misue of swiotlb parameters.
But this patch mainly fixes a crash. Could you please point me to the patch you mentioned?
Thanks,
Zhe
>
>
>
> On Mon, Jan 7, 2019, 4:07 AM Christoph Hellwig <[email protected] <mailto:[email protected]> wrote:
>
> On Mon, Jan 07, 2019 at 04:46:51PM +0800, He Zhe wrote:
> > Kindly ping.
>
> Konrad, I'll pick this up through the DMA mapping tree unless you
> protest in the next few days.
>
On 1/11/19 9:46 AM, He Zhe wrote:
>
> On 1/11/19 1:27 AM, Konrad Rzeszutek Wilk wrote:
>> Let's skip it. There was another patch that would allocate a default 4MB size if it there was an misue of swiotlb parameters.
> But this patch mainly fixes a crash. Could you please point me to the patch you mentioned?
And the v2 is modified according to your suggestion.
Zhe
>
> Thanks,
> Zhe
>
>>
>>
>> On Mon, Jan 7, 2019, 4:07 AM Christoph Hellwig <[email protected] <mailto:[email protected]> wrote:
>>
>> On Mon, Jan 07, 2019 at 04:46:51PM +0800, He Zhe wrote:
>> > Kindly ping.
>>
>> Konrad, I'll pick this up through the DMA mapping tree unless you
>> protest in the next few days.
>>
>