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 <[email protected]> CC: Andrew Morton <[email protected]> Signed-off-by: Jason Wessel <[email protected]> --- include/linux/kdb.h | 4 ++++ kernel/debug/kdb/kdb_bt.c | 2 ++ kernel/debug/kdb/kdb_io.c | 21 +++++++++++++++++---- kernel/debug/kdb/kdb_main.c | 4 ++++ kernel/printk.c | 10 +++++++++- 5 files changed, 36 insertions(+), 5 deletions(-) diff --git a/include/linux/kdb.h b/include/linux/kdb.h index 1d8c1ac..387a916 100644 --- a/include/linux/kdb.h +++ b/include/linux/kdb.h @@ -80,8 +80,12 @@ typedef enum { KDB_REASON_SSTEP, /* Single Step trap. - regs valid */ } kdb_reason_t; +extern int kdb_trap_printk; +extern void vkdb_printf(const char *fmt, va_list args) + __attribute__ ((format (printf, 1, 0))); extern void kdb_printf(const char *, ...) __attribute__ ((format (printf, 1, 2))); + typedef void (*kdb_printf_t)(const char *, ...) __attribute__ ((format (printf, 1, 2))); extern void kdb_init(void); 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 17aa1f2..75f4355 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) { @@ -533,12 +534,12 @@ static int kdb_search_string(char *searched, char *searchfor) return 0; } -void kdb_printf(const char *fmt, ...) +void 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 fnd, len; char *cp, *cp2, *cphold = NULL, replaced_byte = ' '; @@ -548,6 +549,9 @@ void 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 @@ void 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 @@ -803,5 +805,16 @@ kdb_print_out: } else { __release(kdb_printf_lock); } + kdb_trap_printk = saved_trap_printk; preempt_enable(); } + +void kdb_printf(const char *fmt, ...) +{ + va_list ap; + + va_start(ap, fmt); + vkdb_printf(fmt, ap); + va_end(ap); +} + diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c index e0754c8..cb97359 100644 --- a/kernel/debug/kdb/kdb_main.c +++ b/kernel/debug/kdb/kdb_main.c @@ -1058,7 +1058,9 @@ 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..3321a3a 100644 --- a/kernel/printk.c +++ b/kernel/printk.c @@ -33,6 +33,7 @@ #include <linux/bootmem.h> #include <linux/syscalls.h> #include <linux/kexec.h> +#include <linux/kdb.h> #include <linux/ratelimit.h> #include <linux/kmsg_dump.h> @@ -608,7 +609,14 @@ asmlinkage int printk(const char *fmt, ...) { va_list args; int r; - +#ifdef CONFIG_KGDB_KDB + if (unlikely(kdb_trap_printk)) { + va_start(args, fmt); + vkdb_printf(fmt, args); + va_end(args); + return 0; + } +#endif va_start(args, fmt); r = vprintk(fmt, args); va_end(args); -- 1.6.4.rc1 ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev _______________________________________________ Kgdb-bugreport mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport
