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From: tip-bot for Josh Poimboeuf <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: hpa@zytor.com, jpoimboe@redhat.com, tglx@linutronix.de,
	mingo@kernel.org, peterz@infradead.org,
	linux-kernel@vger.kernel.org
Subject: [tip:core/urgent] x86/head/64: Annotate start_cpu0() as non-callable
Date: Thu, 18 Jul 2019 12:11:14 -0700	[thread overview]
Message-ID: <tip-61a73f5cd1a5794626d216cc56e20a1b195c5d0c@git.kernel.org> (raw)
In-Reply-To: <6b1b4505fcb90571a55fa1b52d71fb458ca24454.1563413318.git.jpoimboe@redhat.com>

Commit-ID:  61a73f5cd1a5794626d216cc56e20a1b195c5d0c
Gitweb:     https://git.kernel.org/tip/61a73f5cd1a5794626d216cc56e20a1b195c5d0c
Author:     Josh Poimboeuf <jpoimboe@redhat.com>
AuthorDate: Wed, 17 Jul 2019 20:36:41 -0500
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Thu, 18 Jul 2019 21:01:04 +0200

x86/head/64: Annotate start_cpu0() as non-callable

After an objtool improvement, it complains about the fact that
start_cpu0() jumps to code which has an LRET instruction.

  arch/x86/kernel/head_64.o: warning: objtool: .head.text+0xe4: unsupported instruction in callable function

Technically, start_cpu0() is callable, but it acts nothing like a
callable function.  Prevent objtool from treating it like one by
removing its ELF function annotation.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/6b1b4505fcb90571a55fa1b52d71fb458ca24454.1563413318.git.jpoimboe@redhat.com

---
 arch/x86/kernel/head_64.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index bcd206c8ac90..66b4a7757397 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -253,10 +253,10 @@ END(secondary_startup_64)
  * start_secondary() via .Ljump_to_C_code.
  */
 ENTRY(start_cpu0)
-	movq	initial_stack(%rip), %rsp
 	UNWIND_HINT_EMPTY
+	movq	initial_stack(%rip), %rsp
 	jmp	.Ljump_to_C_code
-ENDPROC(start_cpu0)
+END(start_cpu0)
 #endif
 
 	/* Both SMP bootup and ACPI suspend change these variables */

  reply	other threads:[~2019-07-18 19:11 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-18  1:36 [PATCH v2 00/22] x86, objtool: several fixes/improvements Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 01/22] x86/paravirt: Fix callee-saved function ELF sizes Josh Poimboeuf
2019-07-18 19:07   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 02/22] x86/kvm: Fix fastop function ELF metadata Josh Poimboeuf
2019-07-18 19:08   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 03/22] x86/kvm: Replace vmx_vmenter()'s call to kvm_spurious_fault() with UD2 Josh Poimboeuf
2019-07-18  8:17   ` Paolo Bonzini
2019-07-18 19:08   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 04/22] x86/kvm: Don't call kvm_spurious_fault() from .fixup Josh Poimboeuf
2019-07-18  8:22   ` Paolo Bonzini
2019-07-18 13:16     ` Sean Christopherson
2019-07-18 13:18       ` Paolo Bonzini
2019-07-18 14:12         ` Josh Poimboeuf
2019-07-18 14:13           ` Paolo Bonzini
2019-07-18 14:03       ` Josh Poimboeuf
2019-07-18 19:09   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 05/22] x86/entry: Fix thunk function ELF sizes Josh Poimboeuf
2019-07-18 19:10   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 06/22] x86/head/64: Annotate start_cpu0() as non-callable Josh Poimboeuf
2019-07-18 19:11   ` tip-bot for Josh Poimboeuf [this message]
2019-07-18  1:36 ` [PATCH v2 07/22] x86/uaccess: Remove ELF function annotation from copy_user_handle_tail() Josh Poimboeuf
2019-07-18 19:11   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 08/22] x86/uaccess: Don't leak AC flag into fentry from mcsafe_handle_tail() Josh Poimboeuf
2019-07-18 19:12   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 09/22] x86/uaccess: Remove redundant CLACs in getuser/putuser error paths Josh Poimboeuf
2019-07-18 19:13   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 10/22] bpf: Disable GCC -fgcse optimization for ___bpf_prog_run() Josh Poimboeuf
2019-07-18 19:14   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2020-04-29 21:51     ` BPF vs objtool again Josh Poimboeuf
2020-04-29 22:01       ` Arvind Sankar
2020-04-29 23:41       ` Alexei Starovoitov
2020-04-30  0:13         ` Josh Poimboeuf
2020-04-30  2:10           ` Alexei Starovoitov
2020-04-30  3:53             ` Josh Poimboeuf
2020-04-30  4:24               ` Alexei Starovoitov
2020-04-30  4:43                 ` Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 11/22] objtool: Add mcsafe_handle_tail() to the uaccess safe list Josh Poimboeuf
2019-07-18 19:14   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 12/22] objtool: Track original function across branches Josh Poimboeuf
2019-07-18 19:15   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 13/22] objtool: Refactor function alias logic Josh Poimboeuf
2019-07-18 19:16   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 14/22] objtool: Warn on zero-length functions Josh Poimboeuf
2019-07-18 19:17   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 15/22] objtool: Change dead_end_function() to return boolean Josh Poimboeuf
2019-07-18 19:17   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 16/22] objtool: Do frame pointer check before dead end check Josh Poimboeuf
2019-07-18 19:18   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 17/22] objtool: Refactor sibling call detection logic Josh Poimboeuf
2019-07-18 19:19   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 18/22] objtool: Refactor jump table code Josh Poimboeuf
2019-07-18 19:20   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 19/22] objtool: Support repeated uses of the same C jump table Josh Poimboeuf
2019-07-18 19:20   ` [tip:core/urgent] " tip-bot for Jann Horn
2019-07-18  1:36 ` [PATCH v2 20/22] objtool: Fix seg fault on bad switch table entry Josh Poimboeuf
2019-07-18 19:21   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 21/22] objtool: convert insn type to enum Josh Poimboeuf
2019-07-18 19:22   ` [tip:core/urgent] objtool: Convert " tip-bot for Josh Poimboeuf
2019-07-18  1:36 ` [PATCH v2 22/22] objtool: Support conditional retpolines Josh Poimboeuf
2019-07-18 19:23   ` [tip:core/urgent] " tip-bot for Josh Poimboeuf

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