04a418495e
Add a kmsg_dumper, that dumps the kmsg buffer to stdout, when no console is available. This an enables the printing of early panic() calls triggered in uml_postsetup(). When a panic() call happens so early in the UML kernel no earlyprintk/console is available yet, but with a kmsg_dumper in place the kernel message buffer will be outputted to the user, to give a better hint, of what the failure was. Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Signed-off-by: Richard Weinberger <richard@nod.at>
44 lines
839 B
C
44 lines
839 B
C
#include <linux/kmsg_dump.h>
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#include <linux/console.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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enum kmsg_dump_reason reason)
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{
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static char line[1024];
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size_t len = 0;
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bool con_available = false;
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/* only dump kmsg when no console is available */
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if (!console_trylock())
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return;
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if (console_drivers != NULL)
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con_available = true;
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console_unlock();
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if (con_available == true)
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return;
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printf("kmsg_dump:\n");
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while (kmsg_dump_get_line(dumper, 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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}
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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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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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