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From:   "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
To:     linux-kernel@vger.kernel.org
Cc:     Andi Kleen <ak@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        "H. Peter Anvin" <hpa@zytor.com>, x86@kernel.org,
        Martin Liska <mliska@suse.cz>, Jiri Slaby <jslaby@suse.cz>
Subject: [PATCH 11/46] x86/alternative, lto: Mark int3_*() as global and __visible
Date:   Mon, 14 Nov 2022 12:43:09 +0100
Message-Id: <20221114114344.18650-12-jirislaby@kernel.org>
In-Reply-To: <20221114114344.18650-1-jirislaby@kernel.org>
References: <20221114114344.18650-1-jirislaby@kernel.org>
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From: Andi Kleen <ak@linux.intel.com>

Symbols referenced from assembler (either directly or e.f. from
DEFINE_STATIC_KEY()) need to be global and visible in gcc LTO because
they could end up in a different object file than the assembler. This
can lead to linker errors without this patch.

So mark int3_magic() and int3_selftest_ip() as global and __visible.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Martin Liska <mliska@suse.cz>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 arch/x86/kernel/alternative.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 5cadcea035e0..05e5eb9cbd51 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -823,11 +823,12 @@ extern struct paravirt_patch_site __start_parainstructions[],
  * convention such that we can 'call' it from assembly.
  */
 
-extern void int3_magic(unsigned int *ptr); /* defined in asm */
+extern __visible void int3_magic(unsigned int *ptr); /* defined in asm */
 
 asm (
 "	.pushsection	.init.text, \"ax\", @progbits\n"
 "	.type		int3_magic, @function\n"
+"	.globl		int3_magic\n"
 "int3_magic:\n"
 	ANNOTATE_NOENDBR
 "	movl	$1, (%" _ASM_ARG1 ")\n"
@@ -836,7 +837,7 @@ asm (
 "	.popsection\n"
 );
 
-extern void int3_selftest_ip(void); /* defined in asm below */
+extern __visible void int3_selftest_ip(void); /* defined in asm below */
 
 static int __init
 int3_exception_notify(struct notifier_block *self, unsigned long val, void *data)
-- 
2.38.1