From 9f0844de49cf0557d5c359131004acbb179c174e Mon Sep 17 00:00:00 2001 From: John Ogness Date: Thu, 21 Apr 2022 23:28:41 +0206 Subject: [PATCH] printk: get caller_id/timestamp after migration disable Currently the local CPU timestamp and caller_id for the record are collected while migration is enabled. Since this information is CPU-specific, it should be collected with migration disabled. Migration is disabled immediately after collecting this information anyway, so just move the information collection to after the migration disabling. Signed-off-by: John Ogness Reviewed-by: Sergey Senozhatsky Reviewed-by: Petr Mladek Signed-off-by: Petr Mladek Link: https://lore.kernel.org/r/20220421212250.565456-7-john.ogness@linutronix.de --- kernel/printk/printk.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 7bb148a..82ad3d3 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -2063,7 +2063,7 @@ static inline void printk_delay(void) static inline u32 printk_caller_id(void) { return in_task() ? task_pid_nr(current) : - 0x80000000 + raw_smp_processor_id(); + 0x80000000 + smp_processor_id(); } /** @@ -2145,7 +2145,6 @@ int vprintk_store(int facility, int level, const struct dev_printk_info *dev_info, const char *fmt, va_list args) { - const u32 caller_id = printk_caller_id(); struct prb_reserved_entry e; enum printk_info_flags flags = 0; struct printk_record r; @@ -2155,10 +2154,14 @@ int vprintk_store(int facility, int level, u8 *recursion_ptr; u16 reserve_size; va_list args2; + u32 caller_id; u16 text_len; int ret = 0; u64 ts_nsec; + if (!printk_enter_irqsave(recursion_ptr, irqflags)) + return 0; + /* * Since the duration of printk() can vary depending on the message * and state of the ringbuffer, grab the timestamp now so that it is @@ -2167,8 +2170,7 @@ int vprintk_store(int facility, int level, */ ts_nsec = local_clock(); - if (!printk_enter_irqsave(recursion_ptr, irqflags)) - return 0; + caller_id = printk_caller_id(); /* * The sprintf needs to come first since the syslog prefix might be -- 2.7.4