From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 31B9142AA9 for ; Sun, 4 Jan 2026 10:45:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767523513; cv=none; b=K7/ApfCi+JRO3HzeemYQ1XpAnaZmcp6+DHVxclh5IpYgqZ+yxMT80AutS4ZGl9dkbF3xxVf+eascM2Y/1NnrSNwT83NSyCjhSNvTrBT2qzxJZqHlgLGZLoVps6oBA+64FuVYh1KJhOa8QIyoJzepEjv0OY36RPsGNbU4YcijQTY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767523513; c=relaxed/simple; bh=ktwHsdreMOy3nXLKvFJ0EqHl5o10OsVdQQOqs+UIyeA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=E4f8H7a88uL1baUDwgDVBMAEdAPj4lW/5yajtlCTq32MFylfd0MZmVktHYXjP5f+8nm/2+BzCv9XgQbm0DbtpdsKT8WJY0AKnbND1s1CCrCja11pwaWgfMaKJi7E7+IgPjOtbzoX/0C+tWX9eVnvfBuKnI/NcehPHdgFHpSEf30= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=E01QLPcf; arc=none smtp.client-ip=198.175.65.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="E01QLPcf" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1767523511; x=1799059511; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=ktwHsdreMOy3nXLKvFJ0EqHl5o10OsVdQQOqs+UIyeA=; b=E01QLPcfAj7Go9pc+21Pd/+DO3ev/c9xJ+2xk7bxVjoqupdIEIv+hY89 NG9GINQW+daGnwvWidBpO3HNlHZ4V58Wcgbsm8VkkbmGgN0ankSYH/Hl9 8v6+x83no/DIrYznRnqnyhrlY557IvYQV68csK/JwenAFtn4huaKumneh scLX/l1/X+Vb7JdBmCDJd+iTLNJlrFDgkNU55rA49SLnndPPoKoYEtZIH MZr3QfMYrvMwwnM2g6kAtSNy4AONPYNE/tWH5qaMsZ4IfMx4jC75qG++o PI4U2ryMllMJuvON7ZrKwZnSjRcAElg+yJrQvlW8FPovCTSUVaQtRKA29 Q==; X-CSE-ConnectionGUID: S/8qq7vdQVqrFrMkH1I4hA== X-CSE-MsgGUID: ypEfE+8URkSiFadjZkeD/Q== X-IronPort-AV: E=McAfee;i="6800,10657,11659"; a="68832781" X-IronPort-AV: E=Sophos;i="6.21,201,1763452800"; d="scan'208";a="68832781" Received: from orviesa004.jf.intel.com ([10.64.159.144]) by orvoesa111.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Jan 2026 02:45:10 -0800 X-CSE-ConnectionGUID: ADv6f5dcTOe85eJFZpu8VQ== X-CSE-MsgGUID: yObrqGyaQlylT4I8Pv62Zw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.21,201,1763452800"; d="scan'208";a="206690326" Received: from lkp-server01.sh.intel.com (HELO 765f4a05e27f) ([10.239.97.150]) by orviesa004.jf.intel.com with ESMTP; 04 Jan 2026 02:45:09 -0800 Received: from kbuild by 765f4a05e27f with local (Exim 4.98.2) (envelope-from ) id 1vcLbe-000000000W1-196D; Sun, 04 Jan 2026 10:45:06 +0000 Date: Sun, 4 Jan 2026 18:44:30 +0800 From: kernel test robot To: Pnina Feder , Andrew Morton Cc: oe-kbuild-all@lists.linux.dev, Linux Memory Management List , Petr Mladek , Sergey Senozhatsky , linux-kernel@vger.kernel.org, Pnina Feder Subject: Re: [PATCH] panic/kexec: Allow forcing panic execution on a specific CPU Message-ID: <202601041820.6M8cIq2e-lkp@intel.com> References: <20260101123237.277411-1-pnina.feder@mobileye.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260101123237.277411-1-pnina.feder@mobileye.com> Hi Pnina, kernel test robot noticed the following build warnings: [auto build test WARNING on akpm-mm/mm-everything] [also build test WARNING on linus/master v6.19-rc3 next-20251219] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Pnina-Feder/panic-kexec-Allow-forcing-panic-execution-on-a-specific-CPU/20260101-203448 base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything patch link: https://lore.kernel.org/r/20260101123237.277411-1-pnina.feder%40mobileye.com patch subject: [PATCH] panic/kexec: Allow forcing panic execution on a specific CPU config: arm64-randconfig-r122-20260104 (https://download.01.org/0day-ci/archive/20260104/202601041820.6M8cIq2e-lkp@intel.com/config) compiler: clang version 22.0.0git (https://github.com/llvm/llvm-project 9b8addffa70cee5b2acc5454712d9cf78ce45710) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260104/202601041820.6M8cIq2e-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot | Closes: https://lore.kernel.org/oe-kbuild-all/202601041820.6M8cIq2e-lkp@intel.com/ All warnings (new ones prefixed by >>): >> kernel/panic.c:349:69: warning: diagnostic behavior may be improved by adding the 'format(printf, 1, 0)' attribute to the declaration of 'panic_force_target_cpu' [-Wmissing-format-attribute] 321 | vsnprintf(panic_redirect_msg, sizeof(panic_redirect_msg), fmt, args); | ^ kernel/panic.c:321:13: note: 'panic_force_target_cpu' declared here 321 | static bool panic_force_target_cpu(const char *fmt, va_list args) | ^ 1 warning generated. vim +349 kernel/panic.c 308 309 /** 310 * panic_force_target_cpu - Redirect panic to a specific CPU for crash kernel 311 * @fmt: panic message format string 312 * @args: arguments for format string 313 * 314 * Some platforms require panic handling to occur on a specific CPU 315 * for the crash kernel to function correctly. This function redirects 316 * panic handling to CONFIG_PANIC_FORCE_CPU_ID before kexec. 317 * 318 * Returns true if panic should proceed on current CPU. 319 * Returns false (never returns) if panic was redirected. 320 */ 321 static bool panic_force_target_cpu(const char *fmt, va_list args) 322 { 323 static char panic_redirect_msg[1024]; 324 int cpu = raw_smp_processor_id(); 325 int target_cpu = CONFIG_PANIC_FORCE_CPU_ID; 326 327 /* Already on target CPU - proceed normally */ 328 if (cpu == target_cpu) 329 return true; 330 331 /* Target CPU is offline, can't redirect */ 332 if (!cpu_online(target_cpu)) { 333 pr_warn("panic: CPU %d is offline, cannot redirect panic. " 334 "Crash kernel interrupts may be unavailable.\n", target_cpu); 335 return true; 336 } 337 338 /* Another panic already in progress */ 339 if (panic_in_progress()) { 340 pr_warn("panic: Another panic in progress on CPU %d, cannot redirect to CPU %d. " 341 "Crash kernel interrupts may be unavailable.\n", 342 atomic_read(&panic_cpu), target_cpu); 343 return true; 344 } 345 346 pr_info("panic: Redirecting from CPU %d to CPU %d for crash kernel\n", 347 cpu, target_cpu); 348 > 349 vsnprintf(panic_redirect_msg, sizeof(panic_redirect_msg), fmt, args); 350 351 smp_call_function_single(target_cpu, do_panic_on_target_cpu, panic_redirect_msg, false); 352 353 return false; 354 } 355 #else 356 static inline bool panic_force_target_cpu(const char *fmt, va_list args) 357 { 358 return true; 359 } 360 #endif /* CONFIG_PANIC_FORCE_CPU */ 361 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki