[PATCH] regmap: rbtree: Use alloc_flags for memory allocations

From: Dan Carpenter
Date: Fri Jul 21 2023 - 10:56:11 EST


The kunit tests discovered a sleeping in atomic bug. The allocations
in the regcache-rbtree code should use the map->alloc_flags instead of
GFP_KERNEL.

[ 5.005510] BUG: sleeping function called from invalid context at include/linux/sched/mm.h:306
[ 5.005960] in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 117, name: kunit_try_catch
[ 5.006219] preempt_count: 1, expected: 0
[ 5.006414] 1 lock held by kunit_try_catch/117:
[ 5.006590] #0: 833b9010 (regmap_kunit:86:(config)->lock){....}-{2:2}, at: regmap_lock_spinlock+0x14/0x1c
[ 5.007493] irq event stamp: 162
[ 5.007627] hardirqs last enabled at (161): [<80786738>] crng_make_state+0x1a0/0x294
[ 5.007871] hardirqs last disabled at (162): [<80c531ec>] _raw_spin_lock_irqsave+0x7c/0x80
[ 5.008119] softirqs last enabled at (0): [<801110ac>] copy_process+0x810/0x2138
[ 5.008356] softirqs last disabled at (0): [<00000000>] 0x0
[ 5.008688] CPU: 0 PID: 117 Comm: kunit_try_catch Tainted: G N 6.4.4-rc3-g0e8d2fdfb188 #1
[ 5.009011] Hardware name: Generic DT based system
[ 5.009277] unwind_backtrace from show_stack+0x18/0x1c
[ 5.009497] show_stack from dump_stack_lvl+0x38/0x5c
[ 5.009676] dump_stack_lvl from __might_resched+0x188/0x2d0
[ 5.009860] __might_resched from __kmem_cache_alloc_node+0x1dc/0x25c
[ 5.010061] __kmem_cache_alloc_node from kmalloc_trace+0x30/0xc8
[ 5.010254] kmalloc_trace from regcache_rbtree_write+0x26c/0x468
[ 5.010446] regcache_rbtree_write from _regmap_write+0x88/0x140
[ 5.010634] _regmap_write from regmap_write+0x44/0x68
[ 5.010803] regmap_write from basic_read_write+0x8c/0x270
[ 5.010980] basic_read_write from kunit_try_run_case+0x48/0xa0

Fixes: 28644c809f44 ("regmap: Add the rbtree cache support")
Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Closes: https://lore.kernel.org/all/ee59d128-413c-48ad-a3aa-d9d350c80042@xxxxxxxxxxxx/
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
This patch is similar to what I sent earlier, but I changed
regcache_rbtree_init() back to using GFP_KERNEL.

drivers/base/regmap/regcache-rbtree.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/base/regmap/regcache-rbtree.c b/drivers/base/regmap/regcache-rbtree.c
index fabf87058d80..ae6b8788d5f3 100644
--- a/drivers/base/regmap/regcache-rbtree.c
+++ b/drivers/base/regmap/regcache-rbtree.c
@@ -277,7 +277,7 @@ static int regcache_rbtree_insert_to_block(struct regmap *map,

blk = krealloc(rbnode->block,
blklen * map->cache_word_size,
- GFP_KERNEL);
+ map->alloc_flags);
if (!blk)
return -ENOMEM;

@@ -286,7 +286,7 @@ static int regcache_rbtree_insert_to_block(struct regmap *map,
if (BITS_TO_LONGS(blklen) > BITS_TO_LONGS(rbnode->blklen)) {
present = krealloc(rbnode->cache_present,
BITS_TO_LONGS(blklen) * sizeof(*present),
- GFP_KERNEL);
+ map->alloc_flags);
if (!present)
return -ENOMEM;

@@ -320,7 +320,7 @@ regcache_rbtree_node_alloc(struct regmap *map, unsigned int reg)
const struct regmap_range *range;
int i;

- rbnode = kzalloc(sizeof(*rbnode), GFP_KERNEL);
+ rbnode = kzalloc(sizeof(*rbnode), map->alloc_flags);
if (!rbnode)
return NULL;

@@ -346,13 +346,13 @@ regcache_rbtree_node_alloc(struct regmap *map, unsigned int reg)
}

rbnode->block = kmalloc_array(rbnode->blklen, map->cache_word_size,
- GFP_KERNEL);
+ map->alloc_flags);
if (!rbnode->block)
goto err_free;

rbnode->cache_present = kcalloc(BITS_TO_LONGS(rbnode->blklen),
sizeof(*rbnode->cache_present),
- GFP_KERNEL);
+ map->alloc_flags);
if (!rbnode->cache_present)
goto err_free_block;

--
2.39.2