The patch titled Subject: unicore32: add show_stack_loglvl() has been added to the -mm tree. Its filename is unicore32-add-show_stack_loglvl.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/unicore32-add-show_stack_loglvl.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/unicore32-add-show_stack_loglvl.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Dmitry Safonov <dima@xxxxxxxxxx> Subject: unicore32: add show_stack_loglvl() 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. Introduce show_stack_loglvl(), that eventually will substitute show_stack(). As a nice side-effect - print backtrace in __die() with the same log level as the rest of function. [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@xxxxxxxxxx/T/#u Link: http://lkml.kernel.org/r/20200418201944.482088-40-dima@xxxxxxxxxx Signed-off-by: Dmitry Safonov <dima@xxxxxxxxxx> Cc: Guan Xuetao <gxt@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/unicore32/kernel/traps.c | 27 +++++++++++++++++---------- 1 file changed, 17 insertions(+), 10 deletions(-) --- a/arch/unicore32/kernel/traps.c~unicore32-add-show_stack_loglvl +++ a/arch/unicore32/kernel/traps.c @@ -135,12 +135,13 @@ static void dump_instr(const char *lvl, set_fs(fs); } -static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk) +static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk, + const char *loglvl) { unsigned int fp; int ok = 1; - printk(KERN_DEFAULT "Backtrace: "); + printk("%sBacktrace: ", loglvl); if (!tsk) tsk = current; @@ -153,25 +154,31 @@ static void dump_backtrace(struct pt_reg asm("mov %0, fp" : "=r" (fp) : : "cc"); if (!fp) { - printk("no frame pointer"); + printk("%sno frame pointer", loglvl); ok = 0; } else if (verify_stack(fp)) { - printk("invalid frame pointer 0x%08x", fp); + printk("%sinvalid frame pointer 0x%08x", loglvl, fp); ok = 0; } else if (fp < (unsigned long)end_of_stack(tsk)) - printk("frame pointer underflow"); - printk("\n"); + printk("%sframe pointer underflow", loglvl); + printk("%s\n", loglvl); if (ok) - c_backtrace(fp, KERN_DEFAULT); + c_backtrace(fp, loglvl); } -void show_stack(struct task_struct *tsk, unsigned long *sp) +void show_stack_loglvl(struct task_struct *tsk, unsigned long *sp, + const char *loglvl) { - dump_backtrace(NULL, tsk); + dump_backtrace(NULL, tsk, loglvl); barrier(); } +void show_stack(struct task_struct *tsk, unsigned long *sp) +{ + show_stack_loglvl(tsk, sp, KERN_DEFAULT) +} + static int __die(const char *str, int err, struct thread_info *thread, struct pt_regs *regs) { @@ -196,7 +203,7 @@ static int __die(const char *str, int er if (!user_mode(regs) || in_interrupt()) { dump_mem(KERN_EMERG, "Stack: ", regs->UCreg_sp, THREAD_SIZE + (unsigned long)task_stack_page(tsk)); - dump_backtrace(regs, tsk); + dump_backtrace(regs, tsk, KERN_EMERG); dump_instr(KERN_EMERG, regs); } _ Patches currently in -mm which might be from dima@xxxxxxxxxx are kallsyms-printk-add-loglvl-to-print_ip_sym.patch alpha-add-show_stack_loglvl.patch arc-add-show_stack_loglvl.patch arm-asm-add-loglvl-to-c_backtrace.patch arm-add-loglvl-to-unwind_backtrace.patch arm-add-loglvl-to-dump_backtrace.patch arm-wire-up-dump_backtrace_entrystm.patch arm-add-show_stack_loglvl.patch arm64-add-loglvl-to-dump_backtrace.patch arm64-add-show_stack_loglvl.patch c6x-add-show_stack_loglvl.patch csky-add-show_stack_loglvl.patch h8300-add-show_stack_loglvl.patch hexagon-add-show_stack_loglvl.patch ia64-pass-log-level-as-arg-into-ia64_do_show_stack.patch ia64-add-show_stack_loglvl.patch m68k-add-show_stack_loglvl.patch microblaze-add-loglvl-to-microblaze_unwind_inner.patch microblaze-add-loglvl-to-microblaze_unwind.patch microblaze-add-show_stack_loglvl.patch mips-add-show_stack_loglvl.patch nds32-add-show_stack_loglvl.patch nios2-add-show_stack_loglvl.patch openrisc-add-show_stack_loglvl.patch parisc-add-show_stack_loglvl.patch powerpc-add-show_stack_loglvl.patch riscv-add-show_stack_loglvl.patch s390-add-show_stack_loglvl.patch sh-add-loglvl-to-dump_mem.patch sh-remove-needless-printk.patch sh-add-loglvl-to-printk_address.patch sh-add-loglvl-to-show_trace.patch sh-add-show_stack_loglvl.patch sparc-add-show_stack_loglvl.patch um-sysrq-remove-needless-variable-sp.patch um-add-show_stack_loglvl.patch unicore32-remove-unused-pmode-argument-in-c_backtrace.patch unicore32-add-loglvl-to-c_backtrace.patch unicore32-add-show_stack_loglvl.patch x86-add-missing-const-qualifiers-for-log_lvl.patch x86-add-show_stack_loglvl.patch xtensa-add-loglvl-to-show_trace.patch xtensa-add-show_stack_loglvl.patch sysrq-use-show_stack_loglvl.patch x86-amd_gart-print-stacktrace-for-a-leak-with-kern_err.patch power-use-show_stack_loglvl.patch kdb-dont-play-with-console_loglevel.patch sched-print-stack-trace-with-kern_info.patch kernel-use-show_stack_loglvl.patch kernel-rename-show_stack_loglvl-=-show_stack.patch