e1a261ba59
kmsg_dump doesn't forward the panic reason string to the kmsg_dumper callback. This patch adds a new struct kmsg_dump_detail, that will hold the reason and description, and pass it to the dump() callback. To avoid updating all kmsg_dump() call, it adds a kmsg_dump_desc() function and a macro for backward compatibility. I've written this for drm_panic, but it can be useful for other kmsg_dumper. It allows to see the panic reason, like "sysrq triggered crash" or "VFS: Unable to mount root fs on xxxx" on the drm panic screen. v2: * Use a struct kmsg_dump_detail to hold the reason and description pointer, for more flexibility if we want to add other parameters. (Kees Cook) * Fix powerpc/nvram_64 build, as I didn't update the forward declaration of oops_to_nvram() Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com> Acked-by: Petr Mladek <pmladek@suse.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Kees Cook <kees@kernel.org> Link: https://patchwork.freedesktop.org/patch/msgid/20240702122639.248110-1-jfalempe@redhat.com
66 lines
1.4 KiB
C
66 lines
1.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/kmsg_dump.h>
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#include <linux/spinlock.h>
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#include <linux/console.h>
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#include <linux/string.h>
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#include <shared/init.h>
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#include <shared/kern.h>
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#include <os.h>
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static void kmsg_dumper_stdout(struct kmsg_dumper *dumper,
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struct kmsg_dump_detail *detail)
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{
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static struct kmsg_dump_iter iter;
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static DEFINE_SPINLOCK(lock);
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static char line[1024];
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struct console *con;
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unsigned long flags;
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size_t len = 0;
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int cookie;
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/*
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* If no consoles are available to output crash information, dump
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* the kmsg buffer to stdout.
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*/
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cookie = console_srcu_read_lock();
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for_each_console_srcu(con) {
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/*
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* The ttynull console and disabled consoles are ignored
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* since they cannot output. All other consoles are
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* expected to output the crash information.
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*/
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if (strcmp(con->name, "ttynull") != 0 &&
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(console_srcu_read_flags(con) & CON_ENABLED)) {
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break;
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}
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}
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console_srcu_read_unlock(cookie);
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if (con)
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return;
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if (!spin_trylock_irqsave(&lock, flags))
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return;
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kmsg_dump_rewind(&iter);
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printf("kmsg_dump:\n");
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while (kmsg_dump_get_line(&iter, true, line, sizeof(line), &len)) {
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line[len] = '\0';
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printf("%s", line);
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}
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spin_unlock_irqrestore(&lock, flags);
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}
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static struct kmsg_dumper kmsg_dumper = {
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.dump = kmsg_dumper_stdout
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};
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static int __init kmsg_dumper_stdout_init(void)
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{
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return kmsg_dump_register(&kmsg_dumper);
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}
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__uml_postsetup(kmsg_dumper_stdout_init);
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