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| author | Siddh Raman Pant <code@siddh.me> | 2022-07-31 21:39:13 +0530 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-08-17 14:24:15 +0200 |
| commit | 3bb94ff1e79419d3044772f8656bfc880183c07d (patch) | |
| tree | 337861416082ad9f54ae6bf1d0df32c3e9813762 /arch/x86/mm | |
| parent | 147f66d22f58712dce7ccdd6a1f6cb3ee8042df4 (diff) | |
x86/numa: Use cpumask_available instead of hardcoded NULL check
[ Upstream commit 625395c4a0f4775e0fe00f616888d2e6c1ba49db ]
GCC-12 started triggering a new warning:
arch/x86/mm/numa.c: In function ‘cpumask_of_node’:
arch/x86/mm/numa.c:916:39: warning: the comparison will always evaluate as ‘false’ for the address of ‘node_to_cpumask_map’ will never be NULL [-Waddress]
916 | if (node_to_cpumask_map[node] == NULL) {
| ^~
node_to_cpumask_map is of type cpumask_var_t[].
When CONFIG_CPUMASK_OFFSTACK is set, cpumask_var_t is typedef'd to a
pointer for dynamic allocation, else to an array of one element. The
"wicked game" can be checked on line 700 of include/linux/cpumask.h.
The original code in debug_cpumask_set_cpu() and cpumask_of_node() were
probably written by the original authors with CONFIG_CPUMASK_OFFSTACK=y
(i.e. dynamic allocation) in mind, checking if the cpumask was available
via a direct NULL check.
When CONFIG_CPUMASK_OFFSTACK is not set, GCC gives the above warning
while compiling the kernel.
Fix that by using cpumask_available(), which does the NULL check when
CONFIG_CPUMASK_OFFSTACK is set, otherwise returns true. Use it wherever
such checks are made.
Conditional definitions of cpumask_available() can be found along with
the definition of cpumask_var_t. Check the cpumask.h reference mentioned
above.
Fixes: c032ef60d1aa ("cpumask: convert node_to_cpumask_map[] to cpumask_var_t")
Fixes: de2d9445f162 ("x86: Unify node_to_cpumask_map handling between 32 and 64bit")
Signed-off-by: Siddh Raman Pant <code@siddh.me>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20220731160913.632092-1-code@siddh.me
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/numa.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c index 1e9b93b088db..e360c6892a58 100644 --- a/arch/x86/mm/numa.c +++ b/arch/x86/mm/numa.c @@ -860,7 +860,7 @@ void debug_cpumask_set_cpu(int cpu, int node, bool enable) return; } mask = node_to_cpumask_map[node]; - if (!mask) { + if (!cpumask_available(mask)) { pr_err("node_to_cpumask_map[%i] NULL\n", node); dump_stack(); return; @@ -906,7 +906,7 @@ const struct cpumask *cpumask_of_node(int node) dump_stack(); return cpu_none_mask; } - if (node_to_cpumask_map[node] == NULL) { + if (!cpumask_available(node_to_cpumask_map[node])) { printk(KERN_WARNING "cpumask_of_node(%d): no node_to_cpumask_map!\n", node); |