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| author | Dmitry Safonov <dima@arista.com> | 2020-06-08 21:30:10 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 09:39:10 -0700 |
| commit | e8d7b7353216586f64f5bbcc024951e3cab10a60 (patch) | |
| tree | 45529dfb97899f69fea275cb5c0dd98c747288ba /arch/arm/kernel | |
| parent | 5489ab50c22771ddcad014968141b0d104d650a3 (diff) | |
| download | linux-e8d7b7353216586f64f5bbcc024951e3cab10a60.tar.gz | |
arm: add loglvl to unwind_backtrace()
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 unwind_backtrace() as a preparation for introducing show_stack_loglvl(). As a good side-effect arm_syscall() is now printing errors with the same log level as the backtrace. [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: Russell King <linux@armlinux.org.uk> Cc: Will Deacon <will@kernel.org> Link: http://lkml.kernel.org/r/20200418201944.482088-6-dima@arista.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/arm/kernel')
| -rw-r--r-- | arch/arm/kernel/traps.c | 6 | ||||
| -rw-r--r-- | arch/arm/kernel/unwind.c | 5 |
2 files changed, 6 insertions, 5 deletions
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 7bba15fdce9f..aef52a401ad5 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -204,7 +204,7 @@ static void dump_instr(const char *lvl, struct pt_regs *regs) #ifdef CONFIG_ARM_UNWIND static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) { - unwind_backtrace(regs, tsk); + unwind_backtrace(regs, tsk, KERN_DEFAULT); } #else static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) @@ -664,10 +664,10 @@ asmlinkage int arm_syscall(int no, struct pt_regs *regs) if (user_debug & UDBG_SYSCALL) { pr_err("[%d] %s: arm syscall %d\n", task_pid_nr(current), current->comm, no); - dump_instr("", regs); + dump_instr(KERN_ERR, regs); if (user_mode(regs)) { __show_regs(regs); - c_backtrace(frame_pointer(regs), processor_mode(regs), NULL); + c_backtrace(frame_pointer(regs), processor_mode(regs), KERN_ERR); } } #endif diff --git a/arch/arm/kernel/unwind.c b/arch/arm/kernel/unwind.c index 343cc27b36c4..d2bd0df2318d 100644 --- a/arch/arm/kernel/unwind.c +++ b/arch/arm/kernel/unwind.c @@ -455,7 +455,8 @@ int unwind_frame(struct stackframe *frame) return URC_OK; } -void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk) +void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk, + const char *loglvl) { struct stackframe frame; @@ -493,7 +494,7 @@ void unwind_backtrace(struct pt_regs *regs, struct task_struct *tsk) urc = unwind_frame(&frame); if (urc < 0) break; - dump_backtrace_entry(where, frame.pc, frame.sp - 4, NULL); + dump_backtrace_entry(where, frame.pc, frame.sp - 4, loglvl); } } |