Dmitry Safonov <d...@arista.com> writes: > 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).
Yes, I've had bug reports where the stacktrace is missing, which is annoying. Thanks for trying to fix the problem. > 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. > > Introduce show_stack_loglvl(), that eventually will substitute > show_stack(). > > Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org> > Cc: Michael Ellerman <m...@ellerman.id.au> > Cc: Paul Mackerras <pau...@samba.org> > Cc: linuxppc-dev@lists.ozlabs.org > [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-d...@arista.com/T/#u > Signed-off-by: Dmitry Safonov <d...@arista.com> > --- > arch/powerpc/kernel/process.c | 18 +++++++++++++----- > 1 file changed, 13 insertions(+), 5 deletions(-) This looks good to me. Acked-by: Michael Ellerman <m...@ellerman.id.au> (powerpc) cheers > diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c > index 639ceae7da9d..34b46680a196 100644 > --- a/arch/powerpc/kernel/process.c > +++ b/arch/powerpc/kernel/process.c > @@ -2028,7 +2028,8 @@ unsigned long get_wchan(struct task_struct *p) > > static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH; > > -void show_stack(struct task_struct *tsk, unsigned long *stack) > +void show_stack_loglvl(struct task_struct *tsk, unsigned long *stack, > + const char *loglvl) > { > unsigned long sp, ip, lr, newsp; > int count = 0; > @@ -2053,7 +2054,7 @@ void show_stack(struct task_struct *tsk, unsigned long > *stack) > } > > lr = 0; > - printk("Call Trace:\n"); > + printk("%sCall Trace:\n", loglvl); > do { > if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD)) > break; > @@ -2062,7 +2063,8 @@ void show_stack(struct task_struct *tsk, unsigned long > *stack) > newsp = stack[0]; > ip = stack[STACK_FRAME_LR_SAVE]; > if (!firstframe || ip != lr) { > - printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip); > + printk("%s["REG"] ["REG"] %pS", > + loglvl, sp, ip, (void *)ip); > #ifdef CONFIG_FUNCTION_GRAPH_TRACER > ret_addr = ftrace_graph_ret_addr(current, > &ftrace_idx, ip, stack); > @@ -2084,8 +2086,9 @@ void show_stack(struct task_struct *tsk, unsigned long > *stack) > struct pt_regs *regs = (struct pt_regs *) > (sp + STACK_FRAME_OVERHEAD); > lr = regs->link; > - printk("--- interrupt: %lx at %pS\n LR = %pS\n", > - regs->trap, (void *)regs->nip, (void *)lr); > + printk("%s--- interrupt: %lx at %pS\n LR = %pS\n", > + loglvl, regs->trap, > + (void *)regs->nip, (void *)lr); > firstframe = 1; > } > > @@ -2095,6 +2098,11 @@ void show_stack(struct task_struct *tsk, unsigned long > *stack) > put_task_stack(tsk); > } > > +void show_stack(struct task_struct *tsk, unsigned long *stack) > +{ > + show_stack_loglvl(tsk, stack, KERN_DEFAULT); > +} > + > #ifdef CONFIG_PPC64 > /* Called with hard IRQs off */ > void notrace __ppc64_runlatch_on(void) > -- > 2.23.0
