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authorDmitry Safonov <dima@arista.com>2020-06-08 21:30:50 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-06-09 09:39:11 -0700
commit77530a5277bcab0433d0f68af11e04a5c4d79039 (patch)
treecb91d88568018d6b3a9b4aa19f931fd8e449f99a
parentce23c47a5632612dfaa80bd8f861256a419c0abf (diff)
downloadlinux-77530a5277bcab0433d0f68af11e04a5c4d79039.tar.bz2
microblaze: add loglvl to microblaze_unwind_inner()
Currently, the log-level of show_stack() depends on a platform realization. It creates situations where the headers are printed with lower log level or higher than the stacktrace (depending on a platform or user). Furthermore, it forces the logic decision from user to an architecture side. In result, some users as sysrq/kdb/etc are doing tricks with temporary rising console_loglevel while printing their messages. And in result it not only may print unwanted messages from other CPUs, but also omit printing at all in the unlucky case where the printk() was deferred. Introducing log-level parameter and KERN_UNSUPPRESSED [1] seems an easier approach than introducing more printk buffers. Also, it will consolidate printings with headers. Add log level argument to microblaze_unwind_inner() as a preparation for introducing show_stack_loglvl(). [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Simek <monstr@monstr.eu> Link: http://lkml.kernel.org/r/20200418201944.482088-19-dima@arista.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/microblaze/kernel/unwind.c38
1 files changed, 23 insertions, 15 deletions
diff --git a/arch/microblaze/kernel/unwind.c b/arch/microblaze/kernel/unwind.c
index 4241cdd28ee7..804bf0c99d8b 100644
--- a/arch/microblaze/kernel/unwind.c
+++ b/arch/microblaze/kernel/unwind.c
@@ -154,7 +154,8 @@ static int lookup_prev_stack_frame(unsigned long fp, unsigned long pc,
static void microblaze_unwind_inner(struct task_struct *task,
unsigned long pc, unsigned long fp,
unsigned long leaf_return,
- struct stack_trace *trace);
+ struct stack_trace *trace,
+ const char *loglvl);
/**
* unwind_trap - Unwind through a system trap, that stored previous state
@@ -162,16 +163,18 @@ static void microblaze_unwind_inner(struct task_struct *task,
*/
#ifdef CONFIG_MMU
static inline void unwind_trap(struct task_struct *task, unsigned long pc,
- unsigned long fp, struct stack_trace *trace)
+ unsigned long fp, struct stack_trace *trace,
+ const char *loglvl)
{
/* To be implemented */
}
#else
static inline void unwind_trap(struct task_struct *task, unsigned long pc,
- unsigned long fp, struct stack_trace *trace)
+ unsigned long fp, struct stack_trace *trace,
+ const char *loglvl)
{
const struct pt_regs *regs = (const struct pt_regs *) fp;
- microblaze_unwind_inner(task, regs->pc, regs->r1, regs->r15, trace);
+ microblaze_unwind_inner(task, regs->pc, regs->r1, regs->r15, trace, loglvl);
}
#endif
@@ -184,11 +187,13 @@ static inline void unwind_trap(struct task_struct *task, unsigned long pc,
* the caller's return address.
* @trace : Where to store stack backtrace (PC values).
* NULL == print backtrace to kernel log
+ * @loglvl : Used for printk log level if (trace == NULL).
*/
static void microblaze_unwind_inner(struct task_struct *task,
unsigned long pc, unsigned long fp,
unsigned long leaf_return,
- struct stack_trace *trace)
+ struct stack_trace *trace,
+ const char *loglvl)
{
int ofs = 0;
@@ -214,11 +219,11 @@ static void microblaze_unwind_inner(struct task_struct *task,
const struct pt_regs *regs =
(const struct pt_regs *) fp;
#endif
- pr_info("HW EXCEPTION\n");
+ printk("%sHW EXCEPTION\n", loglvl);
#ifndef CONFIG_MMU
microblaze_unwind_inner(task, regs->r17 - 4,
fp + EX_HANDLER_STACK_SIZ,
- regs->r15, trace);
+ regs->r15, trace, loglvl);
#endif
return;
}
@@ -228,8 +233,8 @@ static void microblaze_unwind_inner(struct task_struct *task,
if ((return_to >= handler->start_addr)
&& (return_to <= handler->end_addr)) {
if (!trace)
- pr_info("%s\n", handler->trap_name);
- unwind_trap(task, pc, fp, trace);
+ printk("%s%s\n", loglvl, handler->trap_name);
+ unwind_trap(task, pc, fp, trace, loglvl);
return;
}
}
@@ -248,13 +253,13 @@ static void microblaze_unwind_inner(struct task_struct *task,
} else {
/* Have we reached userland? */
if (unlikely(pc == task_pt_regs(task)->pc)) {
- pr_info("[<%p>] PID %lu [%s]\n",
- (void *) pc,
+ printk("%s[<%p>] PID %lu [%s]\n",
+ loglvl, (void *) pc,
(unsigned long) task->pid,
task->comm);
break;
} else
- print_ip_sym(KERN_INFO, pc);
+ print_ip_sym(loglvl, pc);
}
/* Stop when we reach anything not part of the kernel */
@@ -285,11 +290,13 @@ static void microblaze_unwind_inner(struct task_struct *task,
*/
void microblaze_unwind(struct task_struct *task, struct stack_trace *trace)
{
+ const char *loglvl = KERN_INFO;
+
if (task) {
if (task == current) {
const struct pt_regs *regs = task_pt_regs(task);
microblaze_unwind_inner(task, regs->pc, regs->r1,
- regs->r15, trace);
+ regs->r15, trace, loglvl);
} else {
struct thread_info *thread_info =
(struct thread_info *)(task->stack);
@@ -299,7 +306,8 @@ void microblaze_unwind(struct task_struct *task, struct stack_trace *trace)
microblaze_unwind_inner(task,
(unsigned long) &_switch_to,
cpu_context->r1,
- cpu_context->r15, trace);
+ cpu_context->r15,
+ trace, loglvl);
}
} else {
unsigned long pc, fp;
@@ -314,7 +322,7 @@ void microblaze_unwind(struct task_struct *task, struct stack_trace *trace)
);
/* Since we are not a leaf function, use leaf_return = 0 */
- microblaze_unwind_inner(current, pc, fp, 0, trace);
+ microblaze_unwind_inner(current, pc, fp, 0, trace, loglvl);
}
}