From: Paolo 'Blaisorblade' Giarrusso Since both UML consoles do not use percpu variables, they may be called when the cpu is still offline, and they may be marked CON_ANYTIME (this is documented in kernel/printk.c, grep for CON_ANYTIME to find mentions of this). Works well in testing done with lock debug enabled, should be safe but is not needed for next release. This would probably help also stderr_console.c, but this is yet to test. Signed-off-by: Paolo 'Blaisorblade' Giarrusso Cc: Jeff Dike Signed-off-by: Andrew Morton --- arch/um/drivers/ssl.c | 2 +- arch/um/drivers/stdio_console.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff -puN arch/um/drivers/ssl.c~uml-mark-both-consoles-as-con_anytime arch/um/drivers/ssl.c --- a/arch/um/drivers/ssl.c~uml-mark-both-consoles-as-con_anytime +++ a/arch/um/drivers/ssl.c @@ -179,7 +179,7 @@ static struct console ssl_cons = { .write = ssl_console_write, .device = ssl_console_device, .setup = ssl_console_setup, - .flags = CON_PRINTBUFFER, + .flags = CON_PRINTBUFFER|CON_ANYTIME, .index = -1, }; diff -puN arch/um/drivers/stdio_console.c~uml-mark-both-consoles-as-con_anytime arch/um/drivers/stdio_console.c --- a/arch/um/drivers/stdio_console.c~uml-mark-both-consoles-as-con_anytime +++ a/arch/um/drivers/stdio_console.c @@ -153,7 +153,7 @@ static struct console stdiocons = { .write = uml_console_write, .device = uml_console_device, .setup = uml_console_setup, - .flags = CON_PRINTBUFFER, + .flags = CON_PRINTBUFFER|CON_ANYTIME, .index = -1, }; _