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-rw-r--r--debian/patches-rt/0086-printk-introduce-CONSOLE_LOG_MAX-for-improved-multi-.patch95
1 files changed, 95 insertions, 0 deletions
diff --git a/debian/patches-rt/0086-printk-introduce-CONSOLE_LOG_MAX-for-improved-multi-.patch b/debian/patches-rt/0086-printk-introduce-CONSOLE_LOG_MAX-for-improved-multi-.patch
new file mode 100644
index 000000000..876f0920e
--- /dev/null
+++ b/debian/patches-rt/0086-printk-introduce-CONSOLE_LOG_MAX-for-improved-multi-.patch
@@ -0,0 +1,95 @@
+From 2b148f755fdd9d276d191e982d525f330cffad0b Mon Sep 17 00:00:00 2001
+From: John Ogness <john.ogness@linutronix.de>
+Date: Thu, 10 Dec 2020 12:48:01 +0106
+Subject: [PATCH 086/323] printk: introduce CONSOLE_LOG_MAX for improved
+ multi-line support
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz
+
+Instead of using "LOG_LINE_MAX + PREFIX_MAX" for temporary buffer
+sizes, introduce CONSOLE_LOG_MAX. This represents the maximum size
+that is allowed to be printed to the console for a single record.
+
+Rather than setting CONSOLE_LOG_MAX to "LOG_LINE_MAX + PREFIX_MAX"
+(1024), increase it to 4096. With a larger buffer size, multi-line
+records that are nearly LOG_LINE_MAX in length will have a better
+chance of being fully printed. (When formatting a record for the
+console, each line of a multi-line record is prepended with a copy
+of the prefix.)
+
+Signed-off-by: John Ogness <john.ogness@linutronix.de>
+---
+ kernel/printk/printk.c | 18 +++++++++++-------
+ 1 file changed, 11 insertions(+), 7 deletions(-)
+
+diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
+index 1f710a2a40b6..1bc4ff19c0d2 100644
+--- a/kernel/printk/printk.c
++++ b/kernel/printk/printk.c
+@@ -412,8 +412,13 @@ static u64 clear_seq;
+ #else
+ #define PREFIX_MAX 32
+ #endif
++
++/* the maximum size allowed to be reserved for a record */
+ #define LOG_LINE_MAX (1024 - PREFIX_MAX)
+
++/* the maximum size of a formatted record (i.e. with prefix added per line) */
++#define CONSOLE_LOG_MAX 4096
++
+ #define LOG_LEVEL(v) ((v) & 0x07)
+ #define LOG_FACILITY(v) ((v) >> 3 & 0xff)
+
+@@ -1475,11 +1480,11 @@ static int syslog_print(char __user *buf, int size)
+ char *text;
+ int len = 0;
+
+- text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
++ text = kmalloc(CONSOLE_LOG_MAX, GFP_KERNEL);
+ if (!text)
+ return -ENOMEM;
+
+- prb_rec_init_rd(&r, &info, text, LOG_LINE_MAX + PREFIX_MAX);
++ prb_rec_init_rd(&r, &info, text, CONSOLE_LOG_MAX);
+
+ while (size > 0) {
+ size_t n;
+@@ -1545,7 +1550,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
+ u64 seq;
+ bool time;
+
+- text = kmalloc(LOG_LINE_MAX + PREFIX_MAX, GFP_KERNEL);
++ text = kmalloc(CONSOLE_LOG_MAX, GFP_KERNEL);
+ if (!text)
+ return -ENOMEM;
+
+@@ -1557,7 +1562,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
+ */
+ seq = find_first_fitting_seq(clear_seq, -1, size, true, time);
+
+- prb_rec_init_rd(&r, &info, text, LOG_LINE_MAX + PREFIX_MAX);
++ prb_rec_init_rd(&r, &info, text, CONSOLE_LOG_MAX);
+
+ len = 0;
+ prb_for_each_record(seq, prb, seq, &r) {
+@@ -2190,8 +2195,7 @@ EXPORT_SYMBOL(printk);
+
+ #else /* CONFIG_PRINTK */
+
+-#define LOG_LINE_MAX 0
+-#define PREFIX_MAX 0
++#define CONSOLE_LOG_MAX 0
+ #define printk_time false
+
+ #define prb_read_valid(rb, seq, r) false
+@@ -2509,7 +2513,7 @@ static inline int can_use_console(void)
+ void console_unlock(void)
+ {
+ static char ext_text[CONSOLE_EXT_LOG_MAX];
+- static char text[LOG_LINE_MAX + PREFIX_MAX];
++ static char text[CONSOLE_LOG_MAX];
+ unsigned long flags;
+ bool do_cond_resched, retry;
+ struct printk_info info;
+--
+2.43.0
+