From: Guillaume Chazarain What's the true meaning of the printk return value? Should it include the priority prefix length of 3? and what about the timing information? In both cases it was broken: strace -e write echo 1 > /dev/kmsg => write(1, "1\n", 2) = 5 strace -e write echo "<1>1" > /dev/kmsg => write(1, "<1>1\n", 5) = 8 The returned length was "length of input string + 3", I made it "length of string output to the log buffer". Note that I couldn't find any printk caller in the kernel interested by its return value besides kmsg_write. Signed-off-by: Guillaume Chazarain Acked-By: Tim Bird Signed-off-by: Andrew Morton --- kernel/printk.c | 6 +++--- 1 files changed, 3 insertions(+), 3 deletions(-) diff -puN kernel/printk.c~printk-return-value-fix-it kernel/printk.c --- 25/kernel/printk.c~printk-return-value-fix-it Tue Nov 15 16:14:05 2005 +++ 25-akpm/kernel/printk.c Tue Nov 15 16:14:05 2005 @@ -569,7 +569,7 @@ asmlinkage int vprintk(const char *fmt, p[1] <= '7' && p[2] == '>') { loglev_char = p[1]; p += 3; - printed_len += 3; + printed_len -= 3; } else { loglev_char = default_message_loglevel + '0'; @@ -584,7 +584,7 @@ asmlinkage int vprintk(const char *fmt, for (tp = tbuf; tp < tbuf + tlen; tp++) emit_log_char(*tp); - printed_len += tlen - 3; + printed_len += tlen; } else { if (p[0] != '<' || p[1] < '0' || p[1] > '7' || p[2] != '>') { @@ -592,8 +592,8 @@ asmlinkage int vprintk(const char *fmt, emit_log_char(default_message_loglevel + '0'); emit_log_char('>'); + printed_len += 3; } - printed_len += 3; } log_level_unknown = 0; if (!*p) _