Re: [PATCH 1/2] printk: Add dictionary information in structure cont
On Fri, Dec 20, 2013 at 10:41 AM, Yoshihiro YUNOMAE wrote: > Add dictionary information in structure cont. > Dictionary information is added when a driver uses structured printk, and the > information is shown in /dev/kmsg. Current kernel directly stores the > information to log_buf. This patch stores the dict information in structure > cont > first, then the information in cont is stored to log_buf. > > Signed-off-by: Yoshihiro YUNOMAE > Cc: Kay Sievers > Cc: Andrew Morton > Cc: Joe Perches > Cc: Tejun Heo > Cc: Frederic Weisbecker > Cc: linux-kernel@vger.kernel.org This is wrong. Please do not apply. Racy ontinuation lines and strutured logging should not be mixed. Continuation lines are a nice kernel hack for debugging, useful to have, but cannot be trusted by userspace. The entire purpose of structured logging is to have trustable atomic logging messages, the both facilities should not be mixed. Thanks, Kay -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 1/2] printk: Add dictionary information in structure cont
Add dictionary information in structure cont.
Dictionary information is added when a driver uses structured printk, and the
information is shown in /dev/kmsg. Current kernel directly stores the
information to log_buf. This patch stores the dict information in structure cont
first, then the information in cont is stored to log_buf.
Signed-off-by: Yoshihiro YUNOMAE
Cc: Kay Sievers
Cc: Andrew Morton
Cc: Joe Perches
Cc: Tejun Heo
Cc: Frederic Weisbecker
Cc: linux-kernel@vger.kernel.org
---
kernel/printk/printk.c | 70
1 file changed, 47 insertions(+), 23 deletions(-)
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index be7c86b..c3662e6 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1391,8 +1391,10 @@ static inline void printk_delay(void)
* reached the console in case of a kernel crash.
*/
static struct cont {
- char buf[LOG_LINE_MAX];
- size_t len; /* length == 0 means unused buffer */
+ char text[LOG_LINE_MAX];
+ size_t text_len;/* length == 0 means unused buffer */
+ char dict[LOG_LINE_MAX];/* stores dict */
+ size_t dict_len;/* 0 means dict is unstored */
size_t cons;/* bytes written to console */
struct task_struct *owner; /* task of first print*/
u64 ts_nsec;/* time of first print */
@@ -1406,7 +1408,7 @@ static void cont_flush(enum log_flags flags)
{
if (cont.flushed)
return;
- if (cont.len == 0)
+ if (cont.text_len == 0)
return;
if (cont.cons) {
@@ -1416,7 +1418,7 @@ static void cont_flush(enum log_flags flags)
* line. LOG_NOCONS suppresses a duplicated output.
*/
log_store(cont.facility, cont.level, flags | LOG_NOCONS,
- cont.ts_nsec, NULL, 0, cont.buf, cont.len);
+ cont.ts_nsec, NULL, 0, cont.text, cont.text_len);
cont.flags = flags;
cont.flushed = true;
} else {
@@ -1425,23 +1427,32 @@ static void cont_flush(enum log_flags flags)
* just submit it to the store and free the buffer.
*/
log_store(cont.facility, cont.level, flags, 0,
- NULL, 0, cont.buf, cont.len);
- cont.len = 0;
+ NULL, 0, cont.text, cont.text_len);
+ cont.text_len = 0;
}
}
-static bool cont_add(int facility, int level, const char *text, size_t len)
+static void cont_dict_add(const char *dict, size_t dict_len)
{
- if (cont.len && cont.flushed)
+ if (cont.dict_len + dict_len > sizeof(cont.dict))
+ return;
+
+ memcpy(cont.dict + cont.dict_len, dict, dict_len);
+ cont.dict_len += dict_len;
+}
+
+static bool cont_add(int facility, int level, const char *text, size_t
text_len)
+{
+ if (cont.text_len && cont.flushed)
return false;
- if (cont.len + len > sizeof(cont.buf)) {
+ if (cont.text_len + text_len > sizeof(cont.text)) {
/* the line gets too long, split it up in separate records */
cont_flush(LOG_CONT);
return false;
}
- if (!cont.len) {
+ if (!cont.text_len) {
cont.facility = facility;
cont.level = level;
cont.owner = current;
@@ -1451,10 +1462,10 @@ static bool cont_add(int facility, int level, const
char *text, size_t len)
cont.flushed = false;
}
- memcpy(cont.buf + cont.len, text, len);
- cont.len += len;
+ memcpy(cont.text + cont.text_len, text, text_len);
+ cont.text_len += text_len;
- if (cont.len > (sizeof(cont.buf) * 80) / 100)
+ if (cont.text_len > (sizeof(cont.text) * 80) / 100)
cont_flush(LOG_CONT);
return true;
@@ -1470,20 +1481,20 @@ static size_t cont_print_text(char *text, size_t size)
size -= textlen;
}
- len = cont.len - cont.cons;
+ len = cont.text_len - cont.cons;
if (len > 0) {
if (len+1 > size)
len = size-1;
- memcpy(text + textlen, cont.buf + cont.cons, len);
+ memcpy(text + textlen, cont.text + cont.cons, len);
textlen += len;
- cont.cons = cont.len;
+ cont.cons = cont.text_len;
}
if (cont.flushed) {
if (cont.flags & LOG_NEWLINE)
text[textlen++] = '\n';
/* got everything, release buffer */
- cont.len = 0;
+ cont.text_len = 0;
}
return textlen;
}
@@ -1576,21 +1587,29 @@ asmlinkage int vprintk_emit(int facility, int level,
if (level == -1)
level =
[PATCH 1/2] printk: Add dictionary information in structure cont
Add dictionary information in structure cont.
Dictionary information is added when a driver uses structured printk, and the
information is shown in /dev/kmsg. Current kernel directly stores the
information to log_buf. This patch stores the dict information in structure cont
first, then the information in cont is stored to log_buf.
Signed-off-by: Yoshihiro YUNOMAE yoshihiro.yunomae...@hitachi.com
Cc: Kay Sievers k...@vrfy.org
Cc: Andrew Morton a...@linux-foundation.org
Cc: Joe Perches j...@perches.com
Cc: Tejun Heo t...@kernel.org
Cc: Frederic Weisbecker fweis...@gmail.com
Cc: linux-kernel@vger.kernel.org
---
kernel/printk/printk.c | 70
1 file changed, 47 insertions(+), 23 deletions(-)
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index be7c86b..c3662e6 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1391,8 +1391,10 @@ static inline void printk_delay(void)
* reached the console in case of a kernel crash.
*/
static struct cont {
- char buf[LOG_LINE_MAX];
- size_t len; /* length == 0 means unused buffer */
+ char text[LOG_LINE_MAX];
+ size_t text_len;/* length == 0 means unused buffer */
+ char dict[LOG_LINE_MAX];/* stores dict */
+ size_t dict_len;/* 0 means dict is unstored */
size_t cons;/* bytes written to console */
struct task_struct *owner; /* task of first print*/
u64 ts_nsec;/* time of first print */
@@ -1406,7 +1408,7 @@ static void cont_flush(enum log_flags flags)
{
if (cont.flushed)
return;
- if (cont.len == 0)
+ if (cont.text_len == 0)
return;
if (cont.cons) {
@@ -1416,7 +1418,7 @@ static void cont_flush(enum log_flags flags)
* line. LOG_NOCONS suppresses a duplicated output.
*/
log_store(cont.facility, cont.level, flags | LOG_NOCONS,
- cont.ts_nsec, NULL, 0, cont.buf, cont.len);
+ cont.ts_nsec, NULL, 0, cont.text, cont.text_len);
cont.flags = flags;
cont.flushed = true;
} else {
@@ -1425,23 +1427,32 @@ static void cont_flush(enum log_flags flags)
* just submit it to the store and free the buffer.
*/
log_store(cont.facility, cont.level, flags, 0,
- NULL, 0, cont.buf, cont.len);
- cont.len = 0;
+ NULL, 0, cont.text, cont.text_len);
+ cont.text_len = 0;
}
}
-static bool cont_add(int facility, int level, const char *text, size_t len)
+static void cont_dict_add(const char *dict, size_t dict_len)
{
- if (cont.len cont.flushed)
+ if (cont.dict_len + dict_len sizeof(cont.dict))
+ return;
+
+ memcpy(cont.dict + cont.dict_len, dict, dict_len);
+ cont.dict_len += dict_len;
+}
+
+static bool cont_add(int facility, int level, const char *text, size_t
text_len)
+{
+ if (cont.text_len cont.flushed)
return false;
- if (cont.len + len sizeof(cont.buf)) {
+ if (cont.text_len + text_len sizeof(cont.text)) {
/* the line gets too long, split it up in separate records */
cont_flush(LOG_CONT);
return false;
}
- if (!cont.len) {
+ if (!cont.text_len) {
cont.facility = facility;
cont.level = level;
cont.owner = current;
@@ -1451,10 +1462,10 @@ static bool cont_add(int facility, int level, const
char *text, size_t len)
cont.flushed = false;
}
- memcpy(cont.buf + cont.len, text, len);
- cont.len += len;
+ memcpy(cont.text + cont.text_len, text, text_len);
+ cont.text_len += text_len;
- if (cont.len (sizeof(cont.buf) * 80) / 100)
+ if (cont.text_len (sizeof(cont.text) * 80) / 100)
cont_flush(LOG_CONT);
return true;
@@ -1470,20 +1481,20 @@ static size_t cont_print_text(char *text, size_t size)
size -= textlen;
}
- len = cont.len - cont.cons;
+ len = cont.text_len - cont.cons;
if (len 0) {
if (len+1 size)
len = size-1;
- memcpy(text + textlen, cont.buf + cont.cons, len);
+ memcpy(text + textlen, cont.text + cont.cons, len);
textlen += len;
- cont.cons = cont.len;
+ cont.cons = cont.text_len;
}
if (cont.flushed) {
if (cont.flags LOG_NEWLINE)
text[textlen++] = '\n';
/* got everything, release buffer */
- cont.len = 0;
+ cont.text_len = 0;
}
return textlen;
}
@@ -1576,21
Re: [PATCH 1/2] printk: Add dictionary information in structure cont
On Fri, Dec 20, 2013 at 10:41 AM, Yoshihiro YUNOMAE yoshihiro.yunomae...@hitachi.com wrote: Add dictionary information in structure cont. Dictionary information is added when a driver uses structured printk, and the information is shown in /dev/kmsg. Current kernel directly stores the information to log_buf. This patch stores the dict information in structure cont first, then the information in cont is stored to log_buf. Signed-off-by: Yoshihiro YUNOMAE yoshihiro.yunomae...@hitachi.com Cc: Kay Sievers k...@vrfy.org Cc: Andrew Morton a...@linux-foundation.org Cc: Joe Perches j...@perches.com Cc: Tejun Heo t...@kernel.org Cc: Frederic Weisbecker fweis...@gmail.com Cc: linux-kernel@vger.kernel.org This is wrong. Please do not apply. Racy ontinuation lines and strutured logging should not be mixed. Continuation lines are a nice kernel hack for debugging, useful to have, but cannot be trusted by userspace. The entire purpose of structured logging is to have trustable atomic logging messages, the both facilities should not be mixed. Thanks, Kay -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
