forked from Openwrt/openwrt
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
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From: Tiezhu Yang <yangtiezhu@loongson.cn>
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Date: Thu, 25 Nov 2021 19:39:32 +0800
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Subject: [PATCH 1/1] MIPS: Fix using smp_processor_id() in preemptible in
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show_cpuinfo()
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There exists the following issue under DEBUG_PREEMPT:
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BUG: using smp_processor_id() in preemptible [00000000] code: systemd/1
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caller is show_cpuinfo+0x460/0xea0
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...
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Call Trace:
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[<ffffffff8020f0dc>] show_stack+0x94/0x128
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[<ffffffff80e6cab4>] dump_stack_lvl+0x94/0xd8
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[<ffffffff80e74c5c>] check_preemption_disabled+0x104/0x110
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[<ffffffff802209c8>] show_cpuinfo+0x460/0xea0
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[<ffffffff80539d54>] seq_read_iter+0xfc/0x4f8
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[<ffffffff804fcc10>] new_sync_read+0x110/0x1b8
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[<ffffffff804ff57c>] vfs_read+0x1b4/0x1d0
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[<ffffffff804ffb18>] ksys_read+0xd0/0x110
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[<ffffffff8021c090>] syscall_common+0x34/0x58
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We can see the following call trace:
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show_cpuinfo()
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cpu_has_fpu
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current_cpu_data
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smp_processor_id()
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$ addr2line -f -e vmlinux 0xffffffff802209c8
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show_cpuinfo
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arch/mips/kernel/proc.c:188
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$ head -188 arch/mips/kernel/proc.c | tail -1
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if (cpu_has_fpu)
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arch/mips/include/asm/cpu-features.h
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# define cpu_has_fpu (current_cpu_data.options & MIPS_CPU_FPU)
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arch/mips/include/asm/cpu-info.h
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#define current_cpu_data cpu_data[smp_processor_id()]
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Based on the above analysis, fix the issue by using raw_cpu_has_fpu
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which calls raw_smp_processor_id() in show_cpuinfo().
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Fixes: 626bfa037299 ("MIPS: kernel: proc: add CPU option reporting")
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Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
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Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
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---
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arch/mips/kernel/proc.c | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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--- a/arch/mips/kernel/proc.c
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+++ b/arch/mips/kernel/proc.c
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@@ -166,7 +166,7 @@ static int show_cpuinfo(struct seq_file
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seq_puts(m, " tx39_cache");
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if (cpu_has_octeon_cache)
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seq_puts(m, " octeon_cache");
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- if (cpu_has_fpu)
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+ if (raw_cpu_has_fpu)
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seq_puts(m, " fpu");
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if (cpu_has_32fpr)
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seq_puts(m, " 32fpr");
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