[PATCH 4.9 52/61] stm class: Use vmalloc for the master map

Greg Kroah-Hartman
2018-06-05T17:07:16Z

From: Alexander Shishkin <alexander.shishkin@linux.intel.com>

commit b5e2ced9bf81393034072dd4d372f6b430bc1f0a upstream.

Fengguang is running into a warning from the buddy allocator:

> swapper/0: page allocation failure: order:9, mode:0x14040c0(GFP_KERNEL|__GFP_COMP), nodemask=(null)
> CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.17.0-rc1 #262
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
> Call Trace:
...
> __kmalloc+0x14b/0x180: ____cache_alloc at mm/slab.c:3127
> stm_register_device+0xf3/0x5c0: stm_register_device at drivers/hwtracing/stm/core.c:695
...

Which is basically a result of the stm class trying to allocate ~512kB
for the dummy_stm with its default parameters. There's no reason, however,
for it not to be vmalloc()ed instead, which is what this patch does.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
CC: stable@vger.kernel.org # v4.4+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/hwtracing/stm/core.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -682,7 +682,7 @@ static void stm_device_release(struct de
{
struct stm_device *stm = to_stm_device(dev);

- kfree(stm);
+ vfree(stm);
}

int stm_register_device(struct device *parent, struct stm_data *stm_data,
@@ -699,7 +699,7 @@ int stm_register_device(struct device *p
return -EINVAL;

nmasters = stm_data->sw_end - stm_data->sw_start + 1;
- stm = kzalloc(sizeof(*stm) + nmasters * sizeof(void *), GFP_KERNEL);
+ stm = vzalloc(sizeof(*stm) + nmasters * sizeof(void *));
if (!stm)
return -ENOMEM;

@@ -752,7 +752,7 @@ err_device:
/* matches device_initialize() above */
put_device(&stm->dev);
err_free:
- kfree(stm);
+ vfree(stm);

return err;
}