Implement KERN_CONT based on the printing CPU rather than on the printing task. As long as the KERN_CONT messages are coming from the same CPU and no non-KERN_CONT messages come, the messages are assumed to belong to each other.
Signed-off-by: John Ogness <[email protected]> --- kernel/printk/printk.c | 73 +++++++++++++++++++++++++++++--------------------- 1 file changed, 42 insertions(+), 31 deletions(-) diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index eebe6f4fdbba..306e7575499c 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -1649,8 +1649,6 @@ static void call_console_drivers(u64 seq, const char *ext_text, size_t ext_len, } } -/* FIXME: no support for LOG_CONT */ -#if 0 /* * Continuation lines are buffered, and not committed to the record buffer * until the line is complete, or a race forces it. The line fragments @@ -1660,52 +1658,57 @@ static void call_console_drivers(u64 seq, const char *ext_text, size_t ext_len, static struct cont { char buf[LOG_LINE_MAX]; size_t len; /* length == 0 means unused buffer */ - struct task_struct *owner; /* task of first print*/ + int cpu_owner; /* cpu of first print*/ u64 ts_nsec; /* time of first print */ u8 level; /* log level of first message */ u8 facility; /* log facility of first message */ enum log_flags flags; /* prefix, newline flags */ -} cont; +} cont[2]; -static void cont_flush(void) +static void cont_flush(int ctx) { - if (cont.len == 0) + struct cont *c = &cont[ctx]; + + if (c->len == 0) return; - log_store(cont.facility, cont.level, cont.flags, cont.ts_nsec, - NULL, 0, cont.buf, cont.len); - cont.len = 0; + log_store(c->facility, c->level, c->flags, c->ts_nsec, c->cpu_owner, + NULL, 0, c->buf, c->len); + c->len = 0; } -static bool cont_add(int facility, int level, enum log_flags flags, const char *text, size_t len) +static void cont_add(int ctx, int cpu, int facility, int level, + enum log_flags flags, const char *text, size_t len) { + struct cont *c = &cont[ctx]; + + if (cpu != c->cpu_owner || !(flags & LOG_CONT)) + cont_flush(ctx); + /* If the line gets too long, split it up in separate records. */ - if (cont.len + len > sizeof(cont.buf)) { - cont_flush(); - return false; - } + while (c->len + len > sizeof(c->buf)) + cont_flush(ctx); - if (!cont.len) { - cont.facility = facility; - cont.level = level; - cont.owner = current; - cont.ts_nsec = local_clock(); - cont.flags = flags; + if (!c->len) { + c->facility = facility; + c->level = level; + c->cpu_owner = cpu; + c->ts_nsec = local_clock(); + c->flags = flags; } - memcpy(cont.buf + cont.len, text, len); - cont.len += len; + memcpy(c->buf + c->len, text, len); + c->len += len; - // The original flags come from the first line, - // but later continuations can add a newline. + /* + * The original flags come from the first line, + * but later continuations can add a newline. + */ if (flags & LOG_NEWLINE) { - cont.flags |= LOG_NEWLINE; - cont_flush(); + c->flags |= LOG_NEWLINE; + cont_flush(ctx); } - - return true; } -#endif /* 0 */ /* ring buffer used as memory allocator for temporary sprint buffers */ DECLARE_STATIC_PRINTKRB(sprint_rb, @@ -1717,6 +1720,7 @@ asmlinkage int vprintk_emit(int facility, int level, const char *fmt, va_list args) { enum log_flags lflags = 0; + int ctx = !!in_nmi(); int printed_len = 0; struct prb_handle h; size_t text_len; @@ -1784,8 +1788,15 @@ asmlinkage int vprintk_emit(int facility, int level, */ printk_emergency(rbuf, level, ts_nsec, cpu, text, text_len); - printed_len = log_store(facility, level, lflags, ts_nsec, cpu, - dict, dictlen, text, text_len); + if ((lflags & LOG_CONT) || !(lflags & LOG_NEWLINE)) { + cont_add(ctx, cpu, facility, level, lflags, text, text_len); + printed_len = text_len; + } else { + if (cpu == cont[ctx].cpu_owner) + cont_flush(ctx); + printed_len = log_store(facility, level, lflags, ts_nsec, cpu, + dict, dictlen, text, text_len); + } prb_commit(&h); return printed_len; -- 2.11.0
