From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 32/93] sh: add loglvl to show_trace() Date: Mon, 08 Jun 2020 21:31:33 -0700 Message-ID: <20200609043133.o3beeNAwI%akpm@linux-foundation.org> References: <20200608212922.5b7fa74ca3f4e2444441b7f9@linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.99]:54500 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725770AbgFIEbe (ORCPT ); Tue, 9 Jun 2020 00:31:34 -0400 In-Reply-To: <20200608212922.5b7fa74ca3f4e2444441b7f9@linux-foundation.org> Sender: mm-commits-owner@vger.kernel.org List-Id: mm-commits@vger.kernel.org To: akpm@linux-foundation.org, dalias@libc.org, dima@arista.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org From: Dmitry Safonov Subject: sh: add loglvl to show_trace() 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 parameter to show_trace() as a preparation to introduce show_stack_loglvl(). [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u Link: http://lkml.kernel.org/r/20200418201944.482088-33-dima@arista.com Signed-off-by: Dmitry Safonov Cc: Rich Felker Signed-off-by: Andrew Morton --- arch/sh/include/asm/processor_32.h | 2 +- arch/sh/kernel/dumpstack.c | 10 +++++----- arch/sh/kernel/process_32.c | 2 +- 3 files changed, 7 insertions(+), 7 deletions(-) --- a/arch/sh/include/asm/processor_32.h~sh-add-loglvl-to-show_trace +++ a/arch/sh/include/asm/processor_32.h @@ -171,7 +171,7 @@ static __inline__ void enable_fpu(void) #define thread_saved_pc(tsk) (tsk->thread.pc) void show_trace(struct task_struct *tsk, unsigned long *sp, - struct pt_regs *regs); + struct pt_regs *regs, const char *loglvl); #ifdef CONFIG_DUMP_CODE void show_code(struct pt_regs *regs); --- a/arch/sh/kernel/dumpstack.c~sh-add-loglvl-to-show_trace +++ a/arch/sh/kernel/dumpstack.c @@ -127,16 +127,16 @@ static const struct stacktrace_ops print }; void show_trace(struct task_struct *tsk, unsigned long *sp, - struct pt_regs *regs) + struct pt_regs *regs, const char *loglvl) { if (regs && user_mode(regs)) return; - printk("\nCall trace:\n"); + printk("%s\nCall trace:\n", loglvl); - unwind_stack(tsk, regs, sp, &print_trace_ops, ""); + unwind_stack(tsk, regs, sp, &print_trace_ops, (void *)loglvl); - printk("\n"); + printk("%s\n", loglvl); if (!tsk) tsk = current; @@ -158,5 +158,5 @@ void show_stack(struct task_struct *tsk, stack = (unsigned long)sp; dump_mem("Stack: ", KERN_DEFAULT, stack, THREAD_SIZE + (unsigned long)task_stack_page(tsk)); - show_trace(tsk, sp, NULL); + show_trace(tsk, sp, NULL, KERN_DEFAULT); } --- a/arch/sh/kernel/process_32.c~sh-add-loglvl-to-show_trace +++ a/arch/sh/kernel/process_32.c @@ -59,7 +59,7 @@ void show_regs(struct pt_regs * regs) printk("MACH: %08lx MACL: %08lx GBR : %08lx PR : %08lx\n", regs->mach, regs->macl, regs->gbr, regs->pr); - show_trace(NULL, (unsigned long *)regs->regs[15], regs); + show_trace(NULL, (unsigned long *)regs->regs[15], regs, KERN_DEFAULT); show_code(regs); } _