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Date: Mon, 25 May 2015 14:46:30 +0200
From: Petr Mladek <pmladek@...e.cz>
To: Andrew Morton <akpm@...ux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@...il.com>,
Steven Rostedt <rostedt@...dmis.org>,
Dave Anderson <anderson@...hat.com>,
"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
Kay Sievers <kay@...y.org>, Jiri Kosina <jkosina@...e.cz>,
Michal Hocko <mhocko@...e.cz>, Jan Kara <jack@...e.cz>,
linux-kernel@...r.kernel.org, Wang Long <long.wanglong@...wei.com>,
peifeiyue@...wei.com, dzickus@...hat.com, morgan.wang@...wei.com,
sasha.levin@...cle.com, Petr Mladek <pmladek@...e.cz>
Subject: [PATCH 07/10] printk: Split text formatting and analyze from vprintk_emit()
vprintk_emit() is too long. Let's move the text formatting and
the text analyze into a separate function.
I am not super happy with the result. The primary aim is to reduce
future mistakes when backporting fixes in this code to older stable
kernel releases. Therefore I want to keep the changes in the code
at minimum. Especially, I want to avoid conversion of @text into
"char **" because it is harder to read.
Well, there is one exception. @level is accessed via a pointer.
It looks safe because compiler warns about type mismatch when
the access is not updated. Also it used only in a very
simple code.
Better ideas are welcome!
This patch just shuffles the code. There is no change in
the functionality.
Signed-off-by: Petr Mladek <pmladek@...e.cz>
---
kernel/printk/printk.c | 122 +++++++++++++++++++++++++++++++------------------
1 file changed, 78 insertions(+), 44 deletions(-)
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 91b8043044ac..7d009144f97f 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1740,13 +1740,85 @@ static int vprintk_delayed_warnings(void)
return printed_len;
}
+/**
+ * vprintk_format_and_analyze - format and analyze the text message
+ * @fmt: text format
+ * @args: argumetns used to generate the formated text
+ * @dict: pointer to the message dictionary
+ * @facility: syslog facility
+ * @level: syslog level; might be replaced by the one found in the fomatted text
+ * @ftext: pointer to the formatted text after the syslog prefix
+ * @ftext_len: length of the formatted text without the syslog prefix
+ *
+ * This function modifies the global textbuf and therefore it must be called
+ * under lockbuf_lock!
+ */
+static enum log_flags vprinkt_format_and_analyze(const char *fmt, va_list args,
+ const char *dict, int facility,
+ int *level,
+ char **ftext,
+ size_t *ftext_len)
+{
+ char *text = textbuf;
+ size_t text_len;
+ enum log_flags lflags = 0;
+
+ /*
+ * The printf needs to come first; we need the syslog
+ * prefix which might be passed-in as a parameter.
+ */
+ text_len = vscnprintf(text, sizeof(textbuf), fmt, args);
+
+ /* mark and strip a trailing newline */
+ if (text_len && text[text_len-1] == '\n') {
+ text_len--;
+ lflags |= LOG_NEWLINE;
+ }
+
+ /* strip kernel syslog prefix and extract log level or control flags */
+ if (facility == 0) {
+ int kern_level = printk_get_level(text);
+
+ if (kern_level) {
+ const char *end_of_header = printk_skip_level(text);
+
+ switch (kern_level) {
+ case '0' ... '7':
+ if (*level == LOGLEVEL_DEFAULT)
+ *level = kern_level - '0';
+ /* fallthrough */
+ case 'd': /* KERN_DEFAULT */
+ lflags |= LOG_PREFIX;
+ }
+ /*
+ * No need to check length here because vscnprintf
+ * put '\0' at the end of the string. Only valid and
+ * newly printed level is detected.
+ */
+ text_len -= end_of_header - text;
+ text = (char *)end_of_header;
+ }
+ }
+
+ if (*level == LOGLEVEL_DEFAULT)
+ *level = default_message_loglevel;
+
+ if (dict)
+ lflags |= LOG_PREFIX|LOG_NEWLINE;
+
+ *ftext = text;
+ *ftext_len = text_len;
+
+ return lflags;
+}
+
asmlinkage int vprintk_emit(int facility, int level,
const char *dict, size_t dictlen,
const char *fmt, va_list args)
{
- char *text = textbuf;
- size_t text_len = 0;
- enum log_flags lflags = 0;
+ char *text;
+ size_t text_len;
+ enum log_flags lflags;
unsigned long flags;
int this_cpu;
int printed_len = 0;
@@ -1808,47 +1880,9 @@ asmlinkage int vprintk_emit(int facility, int level,
printed_len += vprintk_delayed_warnings();
- /*
- * The printf needs to come first; we need the syslog
- * prefix which might be passed-in as a parameter.
- */
- text_len = vscnprintf(text, sizeof(textbuf), fmt, args);
-
- /* mark and strip a trailing newline */
- if (text_len && text[text_len-1] == '\n') {
- text_len--;
- lflags |= LOG_NEWLINE;
- }
-
- /* strip kernel syslog prefix and extract log level or control flags */
- if (facility == 0) {
- int kern_level = printk_get_level(text);
-
- if (kern_level) {
- const char *end_of_header = printk_skip_level(text);
- switch (kern_level) {
- case '0' ... '7':
- if (level == LOGLEVEL_DEFAULT)
- level = kern_level - '0';
- /* fallthrough */
- case 'd': /* KERN_DEFAULT */
- lflags |= LOG_PREFIX;
- }
- /*
- * No need to check length here because vscnprintf
- * put '\0' at the end of the string. Only valid and
- * newly printed level is detected.
- */
- text_len -= end_of_header - text;
- text = (char *)end_of_header;
- }
- }
-
- if (level == LOGLEVEL_DEFAULT)
- level = default_message_loglevel;
-
- if (dict)
- lflags |= LOG_PREFIX|LOG_NEWLINE;
+ lflags = vprinkt_format_and_analyze(fmt, args, dict, facility,
+ &level,
+ &text, &text_len);
if (!(lflags & LOG_NEWLINE)) {
/*
--
1.8.5.6
--
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