https://github.com/torvalds/linux
Revision 1cab5bd69eb1f995ced2d7576cb15f8a8941fd85 authored by Tiezhu Yang on 25 November 2021, 11:39:32 UTC, committed by Thomas Bogendoerfer on 25 November 2021, 15:45:58 UTC
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>
1 parent fbf3bce
Tip revision: 1cab5bd69eb1f995ced2d7576cb15f8a8941fd85 authored by Tiezhu Yang on 25 November 2021, 11:39:32 UTC
MIPS: Fix using smp_processor_id() in preemptible in show_cpuinfo()
MIPS: Fix using smp_processor_id() in preemptible in show_cpuinfo()
Tip revision: 1cab5bd
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