From: Jeff Dike Fix the passing of printk output back to the mconsole client. The existing code was somewhat confused, accumulating output in a buffer, but writing it out entirely whenever a new chunk was added. This is fixed. The earlier include cleanups caused linux/sysrq.h to not be included - this is fixed by adding the include back, under CONFIG_MAGIC_SYSRQ. CONFIG_MAGIC_SYSRQ is also defaulted to on in defconfig. Signed-off-by: Jeff Dike Signed-off-by: Andrew Morton --- arch/um/defconfig | 2 +- arch/um/drivers/mconsole_kern.c | 23 +++++++++-------------- 2 files changed, 10 insertions(+), 15 deletions(-) diff -puN arch/um/defconfig~uml-sysrq-and-mconsole-fixes arch/um/defconfig --- a/arch/um/defconfig~uml-sysrq-and-mconsole-fixes +++ a/arch/um/defconfig @@ -80,7 +80,7 @@ CONFIG_BINFMT_MISC=m # CONFIG_HOSTFS is not set # CONFIG_HPPFS is not set CONFIG_MCONSOLE=y -# CONFIG_MAGIC_SYSRQ is not set +CONFIG_MAGIC_SYSRQ=y CONFIG_NEST_LEVEL=0 # CONFIG_HIGHMEM is not set CONFIG_KERNEL_STACK_ORDER=0 diff -puN arch/um/drivers/mconsole_kern.c~uml-sysrq-and-mconsole-fixes arch/um/drivers/mconsole_kern.c --- a/arch/um/drivers/mconsole_kern.c~uml-sysrq-and-mconsole-fixes +++ a/arch/um/drivers/mconsole_kern.c @@ -632,10 +632,9 @@ struct mconsole_output { static DEFINE_SPINLOCK(client_lock); static LIST_HEAD(clients); static char console_buf[MCONSOLE_MAX_DATA]; -static int console_index = 0; static void console_write(struct console *console, const char *string, - unsigned len) + unsigned int len) { struct list_head *ele; int n; @@ -643,24 +642,18 @@ static void console_write(struct console if (list_empty(&clients)) return; - while (1) { - n = min((size_t) len, ARRAY_SIZE(console_buf) - console_index); - strncpy(&console_buf[console_index], string, n); - console_index += n; + while (len > 0) { + n = min((size_t) len, ARRAY_SIZE(console_buf)); + strncpy(console_buf, string, n); string += n; len -= n; - if (len == 0) - return; list_for_each(ele, &clients) { struct mconsole_output *entry; entry = list_entry(ele, struct mconsole_output, list); - mconsole_reply_len(entry->req, console_buf, - console_index, 0, 1); + mconsole_reply_len(entry->req, console_buf, n, 0, 1); } - - console_index = 0; } } @@ -690,8 +683,7 @@ static void with_console(struct mc_reque (*proc)(arg); - mconsole_reply_len(req, console_buf, console_index, 0, 0); - console_index = 0; + mconsole_reply_len(req, "", 0, 0, 0); spin_lock_irqsave(&client_lock, flags); list_del(&entry.list); @@ -699,6 +691,9 @@ static void with_console(struct mc_reque } #ifdef CONFIG_MAGIC_SYSRQ + +#include + static void sysrq_proc(void *arg) { char *op = arg; _