Messages in this thread Patch in this message | | | Date | Tue, 31 Jul 2007 11:36:08 -0700 | From | Andrew Morton <> | Subject | Re: early_printk accessing __log_buf |
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On Tue, 31 Jul 2007 03:47:59 -0400 "Mike Frysinger" <vapier.adi@gmail.com> wrote:
> attached > -mike > > > [linux-log_buf_read.patch application/octet-stream (2.4KB)]
Please sort out the email thing if you plan on sending more kernel patches?
Incremental:
From: Andrew Morton <akpm@linux-foundation.org>
- compile fix
- Race fix: oops_in_progress can change at any time
- coding-style fixlets.
Cc: Greg Ungerer <gerg@snapgear.com> Cc: Mike Frysinger <vapier.adi@gmail.com> Cc: Mike Frysinger <vapier@gentoo.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Robin Getz <rgetz@blackfin.uclinux.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: Tim Bird <tim.bird@am.sony.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> ---
include/linux/kernel.h | 2 +- kernel/printk.c | 12 ++++++++---- 2 files changed, 9 insertions(+), 5 deletions(-)
diff -puN include/linux/kernel.h~early_printk-accessing-__log_buf-fix include/linux/kernel.h --- a/include/linux/kernel.h~early_printk-accessing-__log_buf-fix +++ a/include/linux/kernel.h @@ -168,7 +168,7 @@ static inline int printk(const char *s, __attribute__ ((format (printf, 1, 2))); static inline int __cold printk(const char *s, ...) { return 0; } static inline int log_buf_get_len(void) { return 0; } -static inline int log_buf_read(int idx); { return 0; } +static inline int log_buf_read(int idx) { return 0; } static inline int log_buf_copy(char *dest, int idx, int len) { return 0; } #endif diff -puN kernel/printk.c~early_printk-accessing-__log_buf-fix kernel/printk.c --- a/kernel/printk.c~early_printk-accessing-__log_buf-fix +++ a/kernel/printk.c @@ -233,14 +233,17 @@ int log_buf_get_len(void) int log_buf_copy(char *dest, int idx, int len) { int ret, max; + bool took_lock = false; - if (!oops_in_progress) + if (!oops_in_progress) { spin_lock_irq(&logbuf_lock); + took_lock = true; + } max = log_buf_get_len(); - if (idx < 0 || idx >= max) + if (idx < 0 || idx >= max) { ret = -1; - else { + } else { if (len > max) len = max; ret = len; @@ -250,7 +253,7 @@ int log_buf_copy(char *dest, int idx, in } } - if (!oops_in_progress) + if (took_lock) spin_unlock_irq(&logbuf_lock); return ret; @@ -262,6 +265,7 @@ int log_buf_copy(char *dest, int idx, in int log_buf_read(int idx) { char ret; + if (log_buf_copy(&ret, idx, 1) == 1) return ret; else _ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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