From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Subject: [patch 07/93] arm: wire up dump_backtrace_{entry,stm} Date: Mon, 08 Jun 2020 21:30:16 -0700 Message-ID: <20200609043016.eajQgcRP-%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]:52998 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726896AbgFIEaR (ORCPT ); Tue, 9 Jun 2020 00:30:17 -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, dima@arista.com, linux-mm@kvack.org, linux@armlinux.org.uk, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, will@kernel.org From: Dmitry Safonov Subject: arm: wire up dump_backtrace_{entry,stm} 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. Now that c_backtrace() always emits correct loglvl, use it for printing. [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u Link: http://lkml.kernel.org/r/20200418201944.482088-8-dima@arista.com Signed-off-by: Dmitry Safonov Cc: Russell King Cc: Will Deacon Signed-off-by: Andrew Morton --- arch/arm/kernel/traps.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) --- a/arch/arm/kernel/traps.c~arm-wire-up-dump_backtrace_entrystm +++ a/arch/arm/kernel/traps.c @@ -68,13 +68,15 @@ void dump_backtrace_entry(unsigned long unsigned long end = frame + 4 + sizeof(struct pt_regs); #ifdef CONFIG_KALLSYMS - printk("[<%08lx>] (%ps) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from); + printk("%s[<%08lx>] (%ps) from [<%08lx>] (%pS)\n", + loglvl, where, (void *)where, from, (void *)from); #else - printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from); + printk("%sFunction entered at [<%08lx>] from [<%08lx>]\n", + loglvl, where, from); #endif if (in_entry_text(from) && end <= ALIGN(frame, THREAD_SIZE)) - dump_mem("", "Exception stack", frame + 4, end); + dump_mem(loglvl, "Exception stack", frame + 4, end); } void dump_backtrace_stm(u32 *stack, u32 instruction, const char *loglvl) @@ -89,12 +91,12 @@ void dump_backtrace_stm(u32 *stack, u32 if (++x == 6) { x = 0; p = str; - printk("%s\n", str); + printk("%s%s\n", loglvl, str); } } } if (p != str) - printk("%s\n", str); + printk("%s%s\n", loglvl, str); } #ifndef CONFIG_ARM_UNWIND _