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authorTiezhu Yang <yangtiezhu@loongson.cn>2021-11-25 12:39:32 +0100
committerThomas Bogendoerfer <tsbogend@alpha.franken.de>2021-11-25 16:45:58 +0100
commit1cab5bd69eb1f995ced2d7576cb15f8a8941fd85 (patch)
tree6eeb62e263f710acf2ee8efbe789ac0563f3b742 /arch/mips
parentMIPS: boot/compressed/: add __ashldi3 to target for ZSTD compression (diff)
downloadlinux-1cab5bd69eb1f995ced2d7576cb15f8a8941fd85.tar.xz
linux-1cab5bd69eb1f995ced2d7576cb15f8a8941fd85.zip
MIPS: Fix using smp_processor_id() in preemptible in show_cpuinfo()
There exists the following issue under DEBUG_PREEMPT: BUG: using smp_processor_id() in preemptible [00000000] code: systemd/1 caller is show_cpuinfo+0x460/0xea0 ... Call Trace: [<ffffffff8020f0dc>] show_stack+0x94/0x128 [<ffffffff80e6cab4>] dump_stack_lvl+0x94/0xd8 [<ffffffff80e74c5c>] check_preemption_disabled+0x104/0x110 [<ffffffff802209c8>] show_cpuinfo+0x460/0xea0 [<ffffffff80539d54>] seq_read_iter+0xfc/0x4f8 [<ffffffff804fcc10>] new_sync_read+0x110/0x1b8 [<ffffffff804ff57c>] vfs_read+0x1b4/0x1d0 [<ffffffff804ffb18>] ksys_read+0xd0/0x110 [<ffffffff8021c090>] syscall_common+0x34/0x58 We can see the following call trace: show_cpuinfo() cpu_has_fpu current_cpu_data smp_processor_id() $ addr2line -f -e vmlinux 0xffffffff802209c8 show_cpuinfo arch/mips/kernel/proc.c:188 $ head -188 arch/mips/kernel/proc.c | tail -1 if (cpu_has_fpu) arch/mips/include/asm/cpu-features.h # define cpu_has_fpu (current_cpu_data.options & MIPS_CPU_FPU) arch/mips/include/asm/cpu-info.h #define current_cpu_data cpu_data[smp_processor_id()] Based on the above analysis, fix the issue by using raw_cpu_has_fpu which calls raw_smp_processor_id() in show_cpuinfo(). Fixes: 626bfa037299 ("MIPS: kernel: proc: add CPU option reporting") Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Diffstat (limited to 'arch/mips')
-rw-r--r--arch/mips/kernel/proc.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/mips/kernel/proc.c b/arch/mips/kernel/proc.c
index 376a6e2676e9..9f47a889b047 100644
--- a/arch/mips/kernel/proc.c
+++ b/arch/mips/kernel/proc.c
@@ -185,7 +185,7 @@ static int show_cpuinfo(struct seq_file *m, void *v)
seq_puts(m, " tx39_cache");
if (cpu_has_octeon_cache)
seq_puts(m, " octeon_cache");
- if (cpu_has_fpu)
+ if (raw_cpu_has_fpu)
seq_puts(m, " fpu");
if (cpu_has_32fpr)
seq_puts(m, " 32fpr");