From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.aaazen.com (99-33-87-210.lightspeed.sntcca.sbcglobal.net [99.33.87.210]) (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 29D441A2643; Thu, 29 May 2025 04:49:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=99.33.87.210 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748494189; cv=none; b=oAU0l3vy9Ys5jzO+eLfvGE9d4RTdp7jFdT+kQsE8NAw6uqlQ5s3mrtYVSmPLNNAFnNmH0yKxdifnwdB2Q3V5plFp/PGOcyeKgJMbAjkZl4s/dibgaoyxv8RFnvncGBaMlcpmLfeZ6ONAHNVX3ooGPvdPaRzFsQvO9QzQcZLTQRk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748494189; c=relaxed/simple; bh=vXoHgD2spVyw9syIdi/Knpz2uIGNMnz0/ZStU6iAVms=; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type; b=cvL+hJ0lQvbr3QFNRDtcxi2cvrIoVDGNS8yPKrBoCZc4uYg3w1ORusP09clm78jF4l9fPnlayN2AUhOiJ2+hK/8mo6F7SPPi3S5VTIfpS4P1U+opS80LBmapszM7wOuuRMbpnHQeWNE/IwhaFZ5x9TfcvoaZQyp5uCSYBWpKdcA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=aaazen.com; spf=pass smtp.mailfrom=aaazen.com; arc=none smtp.client-ip=99.33.87.210 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=aaazen.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=aaazen.com Received: from localhost (localhost [127.0.0.1]) by thursday.test (OpenSMTPD) with ESMTP id 34c1c53c; Wed, 28 May 2025 21:49:40 -0700 (PDT) Date: Wed, 28 May 2025 21:49:40 -0700 (PDT) From: Richard Narron X-X-Sender: richard@thursday.test To: Pawan Gupta cc: Guenter Roeck , Greg Kroah-Hartman , Linux stable , Linux kernel , Linus Torvalds , Dave Hansen Subject: Re: [PATCH 5.15 00/59] 5.15.184-rc1 review In-Reply-To: <20250528005520.dpip4qe45zvsn7vw@desk> Message-ID: References: <20250520125753.836407405@linuxfoundation.org> <0f597436-5da6-4319-b918-9f57bde5634a@roeck-us.net> <67f03e41-245e-202-f0df-687cc4d9a915@aaazen.com> <20250528005520.dpip4qe45zvsn7vw@desk> 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 On Tue, 27 May 2025, Pawan Gupta wrote: > On Tue, May 27, 2025 at 12:31:47PM -0700, Richard Narron wrote: > > On Fri, 23 May 2025, Guenter Roeck wrote: > > > > > On 5/20/25 06:49, Greg Kroah-Hartman wrote: > > > > This is the start of the stable review cycle for the 5.15.184 release. > > > > There are 59 patches in this series, all will be posted as a response > > > > to this one. If anyone has any issues with these being applied, please > > > > let me know. > > > > > > > > Responses should be made by Thu, 22 May 2025 12:57:37 +0000. > > > > Anything received after that time might be too late. > > > > > > > > > > Build reference: v5.15.184 > > > Compiler version: x86_64-linux-gcc (GCC) 12.4.0 > > > Assembler version: GNU assembler (GNU Binutils) 2.40 > > > > > > Configuration file workarounds: > > > "s/CONFIG_FRAME_WARN=.*/CONFIG_FRAME_WARN=0/" > > > > > > Building i386:defconfig ... passed > > > Building i386:allyesconfig ... failed > > > -------------- > > > Error log: > > > x86_64-linux-ld: arch/x86/kernel/static_call.o: in function > > > `__static_call_transform': > > > static_call.c:(.ref.text+0x46): undefined reference to `cpu_wants_rethunk_at' > > > make[1]: [Makefile:1234: vmlinux] Error 1 (ignored) > > > -------------- > > > Building i386:allmodconfig ... failed > > > -------------- > > > Error log: > > > x86_64-linux-ld: arch/x86/kernel/static_call.o: in function > > > `__static_call_transform': > > > static_call.c:(.ref.text+0x46): undefined reference to `cpu_wants_rethunk_at' > > > make[1]: [Makefile:1234: vmlinux] Error 1 (ignored) > > > -------------- > > > > > > In v5.15.y, cpu_wants_rethunk_at is only built if CONFIG_STACK_VALIDATION=y, > > > but that is not supported for i386 builds. The dummy function in > > > arch/x86/include/asm/alternative.h doesn't take that dependency into account. > > > > > > > I found this bug too using the Slackware 15.0 32-bit kernel > > configuration. > > > > Here is a simple work around patch, but there may be a better solution... > > > > --- arch/x86/kernel/static_call.c.orig 2025-05-22 05:08:28.000000000 -0700 > > +++ arch/x86/kernel/static_call.c 2025-05-27 10:25:27.630496538 -0700 > > @@ -81,9 +81,12 @@ > > break; > > > > case RET: > > + > > +#ifdef CONFIG_64BIT > > if (cpu_wants_rethunk_at(insn)) > > code = text_gen_insn(JMP32_INSN_OPCODE, insn, x86_return_thunk); > > else > > +#endif > > code = &retinsn; > > break; > > > > Another option is to define the empty function when CONFIG_STACK_VALIDATION=n as below: > > --- 8< --- > From: Pawan Gupta > Subject: [PATCH] x86/its: Fix undefined reference to cpu_wants_rethunk_at() > > Below error was reported in 32-bit kernel build: > > static_call.c:(.ref.text+0x46): undefined reference to `cpu_wants_rethunk_at' > make[1]: [Makefile:1234: vmlinux] Error > > This is because the definition of cpu_wants_rethunk_at() depends on > CONFIG_STACK_VALIDATION which is only enabled in 64-bit mode. > > Define the empty function when CONFIG_STACK_VALIDATION=n, rethunk mitigation > is anyways not supported without it. > > Reported-by: Guenter Roeck > Link: https://lore.kernel.org/stable/0f597436-5da6-4319-b918-9f57bde5634a@roeck-us.net/ > Signed-off-by: Pawan Gupta > --- > arch/x86/include/asm/alternative.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h > index 1797f80c10de..a5f704dbb4a1 100644 > --- a/arch/x86/include/asm/alternative.h > +++ b/arch/x86/include/asm/alternative.h > @@ -98,7 +98,7 @@ static inline u8 *its_static_thunk(int reg) > } > #endif > > -#ifdef CONFIG_RETHUNK > +#if defined(CONFIG_RETHUNK) && defined(CONFIG_STACK_VALIDATION) > extern bool cpu_wants_rethunk(void); > extern bool cpu_wants_rethunk_at(void *addr); > #else > -- > 2.34.1 > Thanks for looking at this Pawan. Your new patch works fine on both Slackware 15.0 32-bit and 64-bit systems.