From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Safonov Subject: [PATCHv3 02/50] alpha: Add show_stack_loglvl() Date: Sat, 18 Apr 2020 21:18:56 +0100 Message-ID: <20200418201944.482088-3-dima@arista.com> References: <20200418201944.482088-1-dima@arista.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=googlenew; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=jm4GkFHQF1Q0S/B+KUYWFb+gzMhFBchEH6dpMzDFppU=; b=TfIZtphFbDCvNNoUBEh6Qjg4+p/om4NLEeEMJqMvVZVfBlF4GiuZ4dTeHEdVt5XBEg jD4HjGZsDehfolrvSbTi3FbF94U6F3FqG1p02yDZgTj15rIe/K8E48itbYWH7n7L0Ae9 nJxPGcZW6kUL/i8MgDzsBT8WDklGSaWLLMkYzIX25NPDHxdCFH5M0Kr5KUfSvPPK0iXU 9CBdGG2TVGhli5nFz/fZT1bBcnJ4Ly+mUGBZ48E8AlfSqPxodo+bmRhu0a6mzHhYJiWT ef48erC2KeKOxBm5ejvxIjnMtsCj5ECcRXN4X85gfLnkXT6X1VROSGy6prHgqLCbATnM z0lw== In-Reply-To: <20200418201944.482088-1-dima@arista.com> Sender: linux-alpha-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: linux-kernel@vger.kernel.org Cc: Dmitry Safonov <0x7f454c46@gmail.com>, Dmitry Safonov , Andrew Morton , Greg Kroah-Hartman , Ingo Molnar , Jiri Slaby , Petr Mladek , Sergey Senozhatsky , Steven Rostedt , Tetsuo Handa , Ivan Kokshaysky , Matt Turner , Richard Henderson , linux-alpha@vger.kernel.org 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(). Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Richard Henderson Cc: linux-alpha@vger.kernel.org [1]: https://lore.kernel.org/lkml/20190528002412.1625-1-dima@arista.com/T/#u Signed-off-by: Dmitry Safonov --- arch/alpha/kernel/traps.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) diff --git a/arch/alpha/kernel/traps.c b/arch/alpha/kernel/traps.c index f6b9664ac504..2402f1777f54 100644 --- a/arch/alpha/kernel/traps.c +++ b/arch/alpha/kernel/traps.c @@ -121,10 +121,10 @@ dik_show_code(unsigned int *pc) } static void -dik_show_trace(unsigned long *sp) +dik_show_trace(unsigned long *sp, const char *loglvl) { long i = 0; - printk("Trace:\n"); + printk("%sTrace:\n", loglvl); while (0x1ff8 & (unsigned long) sp) { extern char _stext[], _etext[]; unsigned long tmp = *sp; @@ -133,24 +133,25 @@ dik_show_trace(unsigned long *sp) continue; if (tmp >= (unsigned long) &_etext) continue; - printk("[<%lx>] %pSR\n", tmp, (void *)tmp); + printk("%s[<%lx>] %pSR\n", loglvl, tmp, (void *)tmp); if (i > 40) { - printk(" ..."); + printk("%s ...", loglvl); break; } } - printk("\n"); + printk("%s\n", loglvl); } static int kstack_depth_to_print = 24; -void show_stack(struct task_struct *task, unsigned long *sp) +void show_stack_loglvl(struct task_struct *task, unsigned long *sp, + const char *loglvl) { unsigned long *stack; int i; /* - * debugging aid: "show_stack(NULL);" prints the + * debugging aid: "show_stack(NULL, NULL, KERN_EMERG);" prints the * back trace for this cpu. */ if(sp==NULL) @@ -163,14 +164,19 @@ void show_stack(struct task_struct *task, unsigned long *sp) if ((i % 4) == 0) { if (i) pr_cont("\n"); - printk(" "); + printk("%s ", loglvl); } else { pr_cont(" "); } pr_cont("%016lx", *stack++); } pr_cont("\n"); - dik_show_trace(sp); + dik_show_trace(sp, loglvl); +} + +void show_stack(struct task_struct *task, unsigned long *sp) +{ + show_stack_loglvl(task, sp, KERN_DEFAULT); } void @@ -184,7 +190,7 @@ die_if_kernel(char * str, struct pt_regs *regs, long err, unsigned long *r9_15) printk("%s(%d): %s %ld\n", current->comm, task_pid_nr(current), str, err); dik_show_regs(regs, r9_15); add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE); - dik_show_trace((unsigned long *)(regs+1)); + dik_show_trace((unsigned long *)(regs+1), KERN_DEFAULT); dik_show_code((unsigned int *)regs->pc); if (test_and_set_thread_flag (TIF_DIE_IF_KERNEL)) { @@ -625,7 +631,7 @@ do_entUna(void * va, unsigned long opcode, unsigned long reg, printk("gp = %016lx sp = %p\n", regs->gp, regs+1); dik_show_code((unsigned int *)pc); - dik_show_trace((unsigned long *)(regs+1)); + dik_show_trace((unsigned long *)(regs+1), KERN_DEFAULT); if (test_and_set_thread_flag (TIF_DIE_IF_KERNEL)) { printk("die_if_kernel recursion detected.\n"); -- 2.26.0