diff options
Diffstat (limited to 'kernel/printk/printk.c')
| -rw-r--r-- | kernel/printk/printk.c | 57 |
1 files changed, 33 insertions, 24 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 8362f1979..af4e6968c 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -33,7 +33,6 @@ #include <linux/bootmem.h> #include <linux/memblock.h> #include <linux/syscalls.h> -#include <linux/suspend.h> #include <linux/kexec.h> #include <linux/kdb.h> #include <linux/ratelimit.h> @@ -49,6 +48,7 @@ #include <linux/uio.h> #include <asm/uaccess.h> +#include <asm-generic/sections.h> #define CREATE_TRACE_POINTS #include <trace/events/printk.h> @@ -233,7 +233,11 @@ struct printk_log { u8 facility; /* syslog facility */ u8 flags:5; /* internal record flags */ u8 level:3; /* syslog level */ -}; +} +#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS +__packed __aligned(4) +#endif +; /* * The logbuf_lock protects kmsg buffer, indices, counters. This can be taken @@ -274,30 +278,12 @@ static u32 clear_idx; #define LOG_FACILITY(v) ((v) >> 3 & 0xff) /* record buffer */ -#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) -#define LOG_ALIGN 4 -#else #define LOG_ALIGN __alignof__(struct printk_log) -#endif #define __LOG_BUF_LEN (1 << CONFIG_LOG_BUF_SHIFT) static char __log_buf[__LOG_BUF_LEN] __aligned(LOG_ALIGN); static char *log_buf = __log_buf; static u32 log_buf_len = __LOG_BUF_LEN; -#ifdef CONFIG_TOI_INCREMENTAL -void toi_set_logbuf_untracked(void) -{ - int i; - struct page *log_buf_start_page = virt_to_page(__log_buf); - - printk("Not protecting kernel printk log buffer (%p-%p).\n", - __log_buf, __log_buf + __LOG_BUF_LEN); - - for (i = 0; i < (1 << (CONFIG_LOG_BUF_SHIFT - PAGE_SHIFT)); i++) - SetPageTOI_Untracked(log_buf_start_page + i); -} -#endif - /* Return log buffer address */ char *log_buf_addr_get(void) { @@ -1675,7 +1661,7 @@ asmlinkage int vprintk_emit(int facility, int level, const char *dict, size_t dictlen, const char *fmt, va_list args) { - static int recursion_bug; + static bool recursion_bug; static char textbuf[LOG_LINE_MAX]; char *text = textbuf; size_t text_len = 0; @@ -1711,7 +1697,7 @@ asmlinkage int vprintk_emit(int facility, int level, * it can be printed at the next appropriate moment: */ if (!oops_in_progress && !lockdep_recursing(current)) { - recursion_bug = 1; + recursion_bug = true; local_irq_restore(flags); return 0; } @@ -1726,7 +1712,7 @@ asmlinkage int vprintk_emit(int facility, int level, static const char recursion_msg[] = "BUG: recent printk recursion!"; - recursion_bug = 0; + recursion_bug = false; /* emit KERN_CRIT message */ printed_len += log_store(0, 2, LOG_PREFIX|LOG_NEWLINE, 0, NULL, 0, recursion_msg, @@ -2706,13 +2692,36 @@ int unregister_console(struct console *console) } EXPORT_SYMBOL(unregister_console); +/* + * Some boot consoles access data that is in the init section and which will + * be discarded after the initcalls have been run. To make sure that no code + * will access this data, unregister the boot consoles in a late initcall. + * + * If for some reason, such as deferred probe or the driver being a loadable + * module, the real console hasn't registered yet at this point, there will + * be a brief interval in which no messages are logged to the console, which + * makes it difficult to diagnose problems that occur during this time. + * + * To mitigate this problem somewhat, only unregister consoles whose memory + * intersects with the init section. Note that code exists elsewhere to get + * rid of the boot console as soon as the proper console shows up, so there + * won't be side-effects from postponing the removal. + */ static int __init printk_late_init(void) { struct console *con; for_each_console(con) { if (!keep_bootcon && con->flags & CON_BOOT) { - unregister_console(con); + /* + * Make sure to unregister boot consoles whose data + * resides in the init section before the init section + * is discarded. Boot consoles whose data will stick + * around will automatically be unregistered when the + * proper console replaces them. + */ + if (init_section_intersects(con, sizeof(*con))) + unregister_console(con); } } hotcpu_notifier(console_cpu_notify, 0); |