Re: [PATCH 2/2] powerpc: Show PAGE_SIZE in __die() output
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From: Christophe Leroy <hidden>
Date: 2019-01-08 12:23:18
Le 08/01/2019 à 13:05, Michael Ellerman a écrit :
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The page size the kernel is built with is useful info when debugging a crash, so add it to the output in __die(). Result looks like eg: kernel BUG at drivers/misc/lkdtm/bugs.c:63! Oops: Exception in kernel mode, sig: 5 [#1] LE PAGE_SIZE=64K SMP NR_CPUS=2048 NUMA pSeries Modules linked in: vmx_crypto kvm binfmt_misc ip_tables Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> --- arch/powerpc/kernel/traps.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c index 431a86d3f772..fc972e4eee5f 100644 --- a/arch/powerpc/kernel/traps.c +++ b/arch/powerpc/kernel/traps.c@@ -268,6 +268,18 @@ static int __die(const char *str, struct pt_regs *regs, long err) else seq_buf_puts(&s, "BE "); + seq_buf_puts(&s, "PAGE_SIZE="); + if (IS_ENABLED(CONFIG_PPC_4K_PAGES)) + seq_buf_puts(&s, "4K "); + else if (IS_ENABLED(CONFIG_PPC_16K_PAGES)) + seq_buf_puts(&s, "16K "); + else if (IS_ENABLED(CONFIG_PPC_64K_PAGES)) + seq_buf_puts(&s, "64K "); + else if (IS_ENABLED(CONFIG_PPC_256K_PAGES)) + seq_buf_puts(&s, "256K ");
Can't we build all the above at once using PAGE_SHIFT ? Something like (untested): "%dK ", 1 << (PAGE_SHIFT - 10) Christophe
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+ else + BUILD_BUG_ON(1); + if (IS_ENABLED(CONFIG_PREEMPT)) seq_buf_puts(&s, "PREEMPT ");