diff options
| author | Dawei Li <dawei.li@shingroup.cn> | 2024-03-31 13:34:40 +0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-04-02 18:19:09 -0700 |
| commit | be4e1304419c99a164b4c0e101c7c2a756b635b9 (patch) | |
| tree | a65c73aed9000b5da4f3dfcf5c9fa1e93c682adb /net/iucv | |
| parent | ad6afdfc638aa03b210b5a90026845575b4be25c (diff) | |
net/iucv: Avoid explicit cpumask var allocation on stack
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>
Diffstat (limited to 'net/iucv')
| -rw-r--r-- | net/iucv/iucv.c | 26 |
1 files changed, 18 insertions, 8 deletions
diff --git a/net/iucv/iucv.c b/net/iucv/iucv.c index a4ab615ca3e3..5e37a8ceebcb 100644 --- a/net/iucv/iucv.c +++ b/net/iucv/iucv.c @@ -520,7 +520,7 @@ 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. */ @@ -628,23 +628,33 @@ 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; } /** |