b182634689
Move MIPS cpuinfo patch from pending to backport as it got merged upstream. Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
63 lines
2.0 KiB
Diff
63 lines
2.0 KiB
Diff
From 1cab5bd69eb1f995ced2d7576cb15f8a8941fd85 Mon Sep 17 00:00:00 2001
|
|
From: Tiezhu Yang <yangtiezhu@loongson.cn>
|
|
Date: Thu, 25 Nov 2021 19:39:32 +0800
|
|
Subject: [PATCH 1/1] 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>
|
|
---
|
|
arch/mips/kernel/proc.c | 2 +-
|
|
1 file changed, 1 insertion(+), 1 deletion(-)
|
|
|
|
--- a/arch/mips/kernel/proc.c
|
|
+++ b/arch/mips/kernel/proc.c
|
|
@@ -166,7 +166,7 @@ static int show_cpuinfo(struct seq_file
|
|
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");
|