diff options
Diffstat (limited to 'kernel/printk/printk.c')
| -rw-r--r-- | kernel/printk/printk.c | 42 |
1 files changed, 29 insertions, 13 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index d0d03223b45b..c7b3d5489937 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -423,6 +423,7 @@ static u32 log_next_idx; /* the next printk record to write to the console */ static u64 console_seq; static u32 console_idx; +static u64 exclusive_console_stop_seq; /* the next printk record to read after the last 'clear' command */ static u64 clear_seq; @@ -437,6 +438,7 @@ static u32 clear_idx; /* record buffer */ #define LOG_ALIGN __alignof__(struct printk_log) #define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT) +#define LOG_BUF_LEN_MAX (u32)(1 << 31) static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN); static char *log_buf = __log_buf; static u32 log_buf_len = __LOG_BUF_LEN; @@ -1037,18 +1039,23 @@ void log_buf_vmcoreinfo_setup(void) static unsigned long __initdata new_log_buf_len; /* we practice scaling the ring buffer by powers of 2 */ -static void __init log_buf_len_update(unsigned size) +static void __init log_buf_len_update(u64 size) { + if (size > (u64)LOG_BUF_LEN_MAX) { + size = (u64)LOG_BUF_LEN_MAX; + pr_err("log_buf over 2G is not supported.\n"); + } + if (size) size = roundup_pow_of_two(size); if (size > log_buf_len) - new_log_buf_len = size; + new_log_buf_len = (unsigned long)size; } /* save requested log_buf_len since it's too early to process it */ static int __init log_buf_len_setup(char *str) { - unsigned int size; + u64 size; if (!str) return -EINVAL; @@ -1118,7 +1125,7 @@ void __init setup_log_buf(int early) } if (unlikely(!new_log_buf)) { - pr_err("log_buf_len: %ld bytes not available\n", + pr_err("log_buf_len: %lu bytes not available\n", new_log_buf_len); return; } @@ -1131,8 +1138,8 @@ void __init setup_log_buf(int early) memcpy(log_buf, __log_buf, __LOG_BUF_LEN); logbuf_unlock_irqrestore(flags); - pr_info("log_buf_len: %d bytes\n", log_buf_len); - pr_info("early log buf free: %d(%d%%)\n", + pr_info("log_buf_len: %u bytes\n", log_buf_len); + pr_info("early log buf free: %u(%u%%)\n", free, (free * 100) / __LOG_BUF_LEN); } @@ -2014,6 +2021,7 @@ static u64 syslog_seq; static u32 syslog_idx; static u64 console_seq; static u32 console_idx; +static u64 exclusive_console_stop_seq; static u64 log_first_seq; static u32 log_first_idx; static u64 log_next_seq; @@ -2356,8 +2364,9 @@ again: printk_safe_enter_irqsave(flags); raw_spin_lock(&logbuf_lock); if (console_seq < log_first_seq) { - len = sprintf(text, "** %u printk messages dropped **\n", - (unsigned)(log_first_seq - console_seq)); + len = sprintf(text, + "** %llu printk messages dropped **\n", + log_first_seq - console_seq); /* messages are gone, move to first one */ console_seq = log_first_seq; @@ -2381,6 +2390,12 @@ skip: goto skip; } + /* Output to all consoles once old messages replayed. */ + if (unlikely(exclusive_console && + console_seq >= exclusive_console_stop_seq)) { + exclusive_console = NULL; + } + len += msg_print_text(msg, console_msg_format & MSG_FORMAT_SYSLOG, text + len, @@ -2423,10 +2438,6 @@ skip: console_locked = 0; - /* Release the exclusive_console once it is used */ - if (unlikely(exclusive_console)) - exclusive_console = NULL; - raw_spin_unlock(&logbuf_lock); up_console_sem(); @@ -2704,13 +2715,18 @@ void register_console(struct console *newcon) logbuf_lock_irqsave(flags); console_seq = syslog_seq; console_idx = syslog_idx; - logbuf_unlock_irqrestore(flags); /* * We're about to replay the log buffer. Only do this to the * just-registered console to avoid excessive message spam to * the already-registered consoles. + * + * Set exclusive_console with disabled interrupts to reduce + * race window with eventual console_flush_on_panic() that + * ignores console_lock. */ exclusive_console = newcon; + exclusive_console_stop_seq = console_seq; + logbuf_unlock_irqrestore(flags); } console_unlock(); console_sysfs_notify(); |