summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorDawei Li <dawei.li@shingroup.cn>2024-03-31 08:34:40 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-07-05 10:00:32 +0300
commit2b085521be5292016097b5e7ca81b26be3f7098d (patch)
treeeafa5e1a36dc43c5da538489570792d60ea9c04c
parentb71348be1236398be2d04c5e145fd6eaae86a91b (diff)
downloadlinux-2b085521be5292016097b5e7ca81b26be3f7098d.tar.xz
net/iucv: Avoid explicit cpumask var allocation on stack
[ Upstream commit be4e1304419c99a164b4c0e101c7c2a756b635b9 ] For CONFIG_CPUMASK_OFFSTACK=y kernel, explicit allocation of cpumask variable on stack is not recommended since it can cause potential stack overflow. Instead, kernel code should always use *cpumask_var API(s) to allocate cpumask var in config-neutral way, leaving allocation strategy to CONFIG_CPUMASK_OFFSTACK. Use *cpumask_var API(s) to address it. Signed-off-by: Dawei Li <dawei.li@shingroup.cn> Reviewed-by: Alexandra Winter <wintera@linux.ibm.com> Link: https://lore.kernel.org/r/20240331053441.1276826-2-dawei.li@shingroup.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--net/iucv/iucv.c26
1 files changed, 18 insertions, 8 deletions
diff --git a/net/iucv/iucv.c b/net/iucv/iucv.c
index da4cee91fc63..2f82a6f0992e 100644
--- a/net/iucv/iucv.c
+++ b/net/iucv/iucv.c
@@ -578,7 +578,7 @@ static void iucv_setmask_mp(void)
*/
static void iucv_setmask_up(void)
{
- cpumask_t cpumask;
+ static cpumask_t cpumask;
int cpu;
/* Disable all cpu but the first in cpu_irq_cpumask. */
@@ -686,23 +686,33 @@ static int iucv_cpu_online(unsigned int cpu)
static int iucv_cpu_down_prep(unsigned int cpu)
{
- cpumask_t cpumask;
+ cpumask_var_t cpumask;
+ int ret = 0;
if (!iucv_path_table)
return 0;
- cpumask_copy(&cpumask, &iucv_buffer_cpumask);
- cpumask_clear_cpu(cpu, &cpumask);
- if (cpumask_empty(&cpumask))
+ if (!alloc_cpumask_var(&cpumask, GFP_KERNEL))
+ return -ENOMEM;
+
+ cpumask_copy(cpumask, &iucv_buffer_cpumask);
+ cpumask_clear_cpu(cpu, cpumask);
+ if (cpumask_empty(cpumask)) {
/* Can't offline last IUCV enabled cpu. */
- return -EINVAL;
+ ret = -EINVAL;
+ goto __free_cpumask;
+ }
iucv_retrieve_cpu(NULL);
if (!cpumask_empty(&iucv_irq_cpumask))
- return 0;
+ goto __free_cpumask;
+
smp_call_function_single(cpumask_first(&iucv_buffer_cpumask),
iucv_allow_cpu, NULL, 1);
- return 0;
+
+__free_cpumask:
+ free_cpumask_var(cpumask);
+ return ret;
}
/**