From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AH8x2256XgZDQ2Jy2GDqXAV7iNSk2GdR8/e+KdYynaJ1EqIVHwQ5E00YF260tNDqsTvsyyi1dBDw ARC-Seal: i=1; a=rsa-sha256; t=1519218512; cv=none; d=google.com; s=arc-20160816; b=mwuEz9wSVzY36jWPr5I+UqQtSBHEIuFZwdSfqZMGoZuDmKvdVsuzP72trmwK+4YYnS 57KLU46ug1dPLxy+VbqaA/3ewcq9KtDAOen6/XUf/2jpryhZSS6j48FuJHek3V8iuoTO S+E0ZSPZkIsHjIisiuPQO9LWIRDyp+wBOzdoN5PU5oEkg5NRljgqT7771wExxyQOPqn7 XEgpFVo7igAgcdVJUJDjQwlvxDD+IX834BEMZKCfXFSH9fF/BZOvXmoBW2LJRKUKQQa+ SPvDMIVpZfOkOFQJwyNkg7BSFVRiFebshzHpNzE7we2IakVksX9dwhAEwcIWEVkSYVPW cjUg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=cMrPwaMQoiirOo8EXSJB3UC4yBjcZ5oF2sqPJ9VkKAY=; b=JkF/mlFsbLSrInjBPL4D3yOvUESQXKVsIrhcyKtkndpDpyTHoS9ECxAqYQz5/TzHwt pRiNQhjvE8NWx/4qmG4Dlb5WP1RtTcnhRvYjBaokSPorMQb1b1vKzYgs857Yg7iEYZgt CO95+TzNbRhNlji9yOzmdRuLy2ALl9j210/Spi7ijW38vtBOs781RBX/U6/y6Dvpgv1p WuUcuITGSFE5FRBi0bJS5I8dwLzuQPmXcZRJ7BMHU0BCtHMhU3CMAxdxF3w48OnWLOVw 8u6TyAjEtATyNGREahFUwuEvKM3kIyC1in6ettpfV9l5Kswwp4Mr9rmuf14BVntwe4BA 11tA== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.71.90 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, kbuild test robot , Josh Poimboeuf , Dominik Brodowski , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , kbuild-all@01.org, tipbuild@zytor.com, Ingo Molnar Subject: [PATCH 4.15 066/163] x86/entry/64: Fix paranoid_entry() frame pointer warning Date: Wed, 21 Feb 2018 13:48:15 +0100 Message-Id: <20180221124534.102951733@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180221124529.931834518@linuxfoundation.org> References: <20180221124529.931834518@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1593015601626745893?= X-GMAIL-MSGID: =?utf-8?q?1593016070425901395?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Josh Poimboeuf commit b3ccefaed922529e6a67de7b30af5aa38c76ace9 upstream. With the following commit: f09d160992d1 ("x86/entry/64: Get rid of the ALLOC_PT_GPREGS_ON_STACK and SAVE_AND_CLEAR_REGS macros") ... one of my suggested improvements triggered a frame pointer warning: arch/x86/entry/entry_64.o: warning: objtool: paranoid_entry()+0x11: call without frame pointer save/setup The warning is correct for the build-time code, but it's actually not relevant at runtime because of paravirt patching. The paravirt swapgs call gets replaced with either a SWAPGS instruction or NOPs at runtime. Go back to the previous behavior by removing the ELF function annotation for paranoid_entry() and adding an unwind hint, which effectively silences the warning. Reported-by: kbuild test robot Signed-off-by: Josh Poimboeuf Cc: Dominik Brodowski Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: kbuild-all@01.org Cc: tipbuild@zytor.com Fixes: f09d160992d1 ("x86/entry/64: Get rid of the ALLOC_PT_GPREGS_ON_STACK and SAVE_AND_CLEAR_REGS macros") Link: http://lkml.kernel.org/r/20180212174503.5acbymg5z6p32snu@treble Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/entry/entry_64.S | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -1128,6 +1128,7 @@ idtentry machine_check do_mce has_err * Return: ebx=0: need swapgs on exit, ebx=1: otherwise */ ENTRY(paranoid_entry) + UNWIND_HINT_FUNC cld movl $1, %ebx movl $MSR_GS_BASE, %ecx @@ -1141,7 +1142,7 @@ ENTRY(paranoid_entry) SAVE_AND_SWITCH_TO_KERNEL_CR3 scratch_reg=%rax save_reg=%r14 ret -ENDPROC(paranoid_entry) +END(paranoid_entry) /* * "Paranoid" exit path from exception stack. This is invoked