| Message ID | 20190612033620.3556-1-Anson.Huang@nxp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [1/2] soc: imx8: Fix potential kernel dump in error path | expand |
> From: Anson.Huang@nxp.com [mailto:Anson.Huang@nxp.com] > Sent: Wednesday, June 12, 2019 11:36 AM > > > When SoC's revision value is 0, SoC driver will print out "unknown" in sysfs's > revision node, this "unknown" is a static string which can NOT be freed, this > will caused below kernel dump in later error path which calls kfree: > > kernel BUG at mm/slub.c:3942! > Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Modules linked in: > CPU: 2 PID: 1 Comm: swapper/0 Not tainted > 5.2.0-rc4-next-20190611-00023-g705146c-dirty #2197 Hardware name: NXP > i.MX8MQ EVK (DT) > pstate: 60000005 (nZCv daif -PAN -UAO) > pc : kfree+0x170/0x1b0 > lr : imx8_soc_init+0xc0/0xe4 > sp : ffff00001003bd10 > x29: ffff00001003bd10 x28: ffff00001121e0a0 > x27: ffff000011482000 x26: ffff00001117068c > x25: ffff00001121e100 x24: ffff000011482000 > x23: ffff000010fe2b58 x22: ffff0000111b9ab0 > x21: ffff8000bd9dfba0 x20: ffff0000111b9b70 > x19: ffff7e000043f880 x18: 0000000000001000 > x17: ffff000010d05fa0 x16: ffff0000122e0000 > x15: 0140000000000000 x14: 0000000030360000 > x13: ffff8000b94b5bb0 x12: 0000000000000038 > x11: ffffffffffffffff x10: ffffffffffffffff > x9 : 0000000000000003 x8 : ffff8000b9488147 > x7 : ffff00001003bc00 x6 : 0000000000000000 > x5 : 0000000000000003 x4 : 0000000000000003 > x3 : 0000000000000003 x2 : b8793acd604edf00 > x1 : ffff7e000043f880 x0 : ffff7e000043f888 Call trace: > kfree+0x170/0x1b0 > imx8_soc_init+0xc0/0xe4 > do_one_initcall+0x58/0x1b8 > kernel_init_freeable+0x1cc/0x288 > kernel_init+0x10/0x100 > ret_from_fork+0x10/0x18 > > This patch fixes this potential kernel dump when a chip's revision is "unknown", > it is done by always printing out the revision value. > > Fixes: a7e26f356ca1 ("soc: imx: Add generic i.MX8 SoC driver") > Signed-off-by: Anson Huang <Anson.Huang@nxp.com> > --- > drivers/soc/imx/soc-imx8.c | 10 ++++------ > 1 file changed, 4 insertions(+), 6 deletions(-) > > diff --git a/drivers/soc/imx/soc-imx8.c b/drivers/soc/imx/soc-imx8.c index > 02309a2..86b925a 100644 > --- a/drivers/soc/imx/soc-imx8.c > +++ b/drivers/soc/imx/soc-imx8.c > @@ -96,11 +96,6 @@ static const struct of_device_id imx8_soc_match[] = { > { } > }; > > -#define imx8_revision(soc_rev) \ > - soc_rev ? \ > - kasprintf(GFP_KERNEL, "%d.%d", (soc_rev >> 4) & 0xf, soc_rev & 0xf) : \ > - "unknown" > - > static int __init imx8_soc_init(void) > { > struct soc_device_attribute *soc_dev_attr; @@ -135,7 +130,10 @@ > static int __init imx8_soc_init(void) > soc_rev = data->soc_revision(); > } > > - soc_dev_attr->revision = imx8_revision(soc_rev); > + soc_dev_attr->revision = kasprintf(GFP_KERNEL, > + "%d.%d", > + (soc_rev >> 4) & 0xf, > + soc_rev & 0xf); The revision "0.0" is confusing. I might prefer to check "unknown" before free. Regards Dong Aisheng > if (!soc_dev_attr->revision) { > ret = -ENOMEM; > goto free_soc; > -- > 2.7.4
diff --git a/drivers/soc/imx/soc-imx8.c b/drivers/soc/imx/soc-imx8.c index 02309a2..86b925a 100644 --- a/drivers/soc/imx/soc-imx8.c +++ b/drivers/soc/imx/soc-imx8.c @@ -96,11 +96,6 @@ static const struct of_device_id imx8_soc_match[] = { { } }; -#define imx8_revision(soc_rev) \ - soc_rev ? \ - kasprintf(GFP_KERNEL, "%d.%d", (soc_rev >> 4) & 0xf, soc_rev & 0xf) : \ - "unknown" - static int __init imx8_soc_init(void) { struct soc_device_attribute *soc_dev_attr; @@ -135,7 +130,10 @@ static int __init imx8_soc_init(void) soc_rev = data->soc_revision(); } - soc_dev_attr->revision = imx8_revision(soc_rev); + soc_dev_attr->revision = kasprintf(GFP_KERNEL, + "%d.%d", + (soc_rev >> 4) & 0xf, + soc_rev & 0xf); if (!soc_dev_attr->revision) { ret = -ENOMEM; goto free_soc;