Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757019Ab0ANPGM (ORCPT ); Thu, 14 Jan 2010 10:06:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932234Ab0ANPFS (ORCPT ); Thu, 14 Jan 2010 10:05:18 -0500 Received: from mail.windriver.com ([147.11.1.11]:47779 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756688Ab0ANPBT (ORCPT ); Thu, 14 Jan 2010 10:01:19 -0500 From: Jason Wessel To: linux-kernel@vger.kernel.org Cc: kgdb-bugreport@lists.sourceforge.net, mingo@elte.hu, Jason Wessel , Randy Dunlap , Andrew Morton Subject: [PATCH 25/40] printk,kdb: capture printk() when in kdb shell Date: Thu, 14 Jan 2010 08:59:21 -0600 Message-Id: <1263481176-1897-26-git-send-email-jason.wessel@windriver.com> X-Mailer: git-send-email 1.6.3.1.9.g95405b In-Reply-To: <1263481176-1897-1-git-send-email-jason.wessel@windriver.com> References: <1263481176-1897-1-git-send-email-jason.wessel@windriver.com> X-OriginalArrivalTime: 14 Jan 2010 15:00:55.0616 (UTC) FILETIME=[5F752C00:01CA952A] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4882 Lines: 177 Certain calls from the kdb shell will call out to printk(), and any of these calls should get vectored back to the kdb_printf() so that the kdb pager and processing can be used, as well as to properly channel I/O to the polled I/O devices. CC: Randy Dunlap CC: Andrew Morton Signed-off-by: Jason Wessel --- include/linux/kdb.h | 3 +++ kernel/debug/kdb/kdb_bt.c | 2 ++ kernel/debug/kdb/kdb_io.c | 24 ++++++++++++++++++++---- kernel/debug/kdb/kdb_main.c | 4 ++++ kernel/printk.c | 9 +++++++++ 5 files changed, 38 insertions(+), 4 deletions(-) diff --git a/include/linux/kdb.h b/include/linux/kdb.h index bff071e..118fd49 100644 --- a/include/linux/kdb.h +++ b/include/linux/kdb.h @@ -80,6 +80,9 @@ typedef enum { KDB_REASON_SSTEP, /* Single Step trap. - regs valid */ } kdb_reason_t; +extern int kdb_trap_printk; +extern int vkdb_printf(const char *fmt, va_list args) + __attribute__ ((format (printf, 1, 0))); extern int kdb_printf(const char *, ...) __attribute__ ((format (printf, 1, 2))); typedef int (*kdb_printf_t)(const char *, ...) diff --git a/kernel/debug/kdb/kdb_bt.c b/kernel/debug/kdb/kdb_bt.c index c73402c..176da1a 100644 --- a/kernel/debug/kdb/kdb_bt.c +++ b/kernel/debug/kdb/kdb_bt.c @@ -23,6 +23,7 @@ static void kdb_show_stack(struct task_struct *p, void *addr) { int old_lvl = console_loglevel; console_loglevel = 15; + kdb_trap_printk++; kdb_set_current_task(p); if (addr) { show_stack((struct task_struct *)p, addr); @@ -36,6 +37,7 @@ static void kdb_show_stack(struct task_struct *p, void *addr) show_stack(p, NULL); } console_loglevel = old_lvl; + kdb_trap_printk--; } /* diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c index 32d5521..dd75c20 100644 --- a/kernel/debug/kdb/kdb_io.c +++ b/kernel/debug/kdb/kdb_io.c @@ -29,6 +29,7 @@ #define CMD_BUFLEN 256 char kdb_prompt_str[CMD_BUFLEN]; +int kdb_trap_printk; static void kgdb_transition_check(char *buffer) { @@ -532,12 +533,12 @@ static int kdb_search_string(char *searched, char *searchfor) return 0; } -int kdb_printf(const char *fmt, ...) +int vkdb_printf(const char *fmt, va_list ap) { - va_list ap; int diag; int linecount; int logging, saved_loglevel = 0; + int saved_trap_printk; int got_printf_lock = 0; int retlen = 0; int fnd, len; @@ -548,6 +549,9 @@ int kdb_printf(const char *fmt, ...) unsigned long uninitialized_var(flags); preempt_disable(); + saved_trap_printk = kdb_trap_printk; + kdb_trap_printk = 0; + /* Serialize kdb_printf if multiple cpus try to write at once. * But if any cpu goes recursive in kdb, just print the output, * even if it is interleaved with any other text. @@ -574,9 +578,7 @@ int kdb_printf(const char *fmt, ...) next_avail = kdb_buffer; size_avail = sizeof(kdb_buffer); } - va_start(ap, fmt); vsnprintf(next_avail, size_avail, fmt, ap); - va_end(ap); /* * If kdb_parse() found that the command was cmd xxx | grep yyy @@ -804,6 +806,20 @@ kdb_print_out: } else { __release(kdb_printf_lock); } + kdb_trap_printk = saved_trap_printk; preempt_enable(); return retlen; } + +int kdb_printf(const char *fmt, ...) +{ + va_list ap; + int r; + + va_start(ap, fmt); + r = vkdb_printf(fmt, ap); + va_end(ap); + + return r; +} + diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index 59bb68d..852e003 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -1056,7 +1056,9 @@ static void kdb_dumpregs(struct pt_regs *regs) { int old_lvl = console_loglevel; console_loglevel = 15; + kdb_trap_printk++; show_regs(regs); + kdb_trap_printk--; kdb_printf("\n"); console_loglevel = old_lvl; } @@ -1837,7 +1839,9 @@ static int kdb_sr(int argc, const char **argv) __sysrq_enabled = 1; } + kdb_trap_printk++; handle_sysrq(*argv[1], NULL); + kdb_trap_printk--; return 0; } diff --git a/kernel/printk.c b/kernel/printk.c index 9bee02e..cd17a79 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include @@ -609,6 +610,14 @@ asmlinkage int printk(const char *fmt, ...) va_list args; int r; +#ifdef CONFIG_KGDB_KDB + if (unlikely(kdb_trap_printk)) { + va_start(args, fmt); + r = vkdb_printf(fmt, args); + va_end(args); + return r; + } +#endif va_start(args, fmt); r = vprintk(fmt, args); va_end(args); -- 1.6.3.1.9.g95405b -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/