ac27ecf68a
There's no need for both thunk functions to jump to the same shared
thunk restore code which lives outside the thunk function boundaries.
It disrupts i-cache locality and confuses objtool. Keep it simple by
keeping each thunk's restore code self-contained within the function.
Fixes a bunch of false positive "missing __noreturn" warnings like:
vmlinux.o: warning: objtool: do_arch_prctl_common+0xf4: preempt_schedule_thunk() is missing a __noreturn annotation
Fixes: fedb724c3db5 ("objtool: Detect missing __noreturn annotations")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202305281037.3PaI3tW4-lkp@intel.com/
Link: https://lore.kernel.org/r/46aa8aeb716f302e22e1673ae15ee6fe050b41f4.1685488050.git.jpoimboe@kernel.org
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
49 lines
953 B
ArmAsm
49 lines
953 B
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Save registers before calling assembly functions. This avoids
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* disturbance of register allocation in some inline assembly constructs.
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* Copyright 2001,2002 by Andi Kleen, SuSE Labs.
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*/
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#include <linux/linkage.h>
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#include "calling.h"
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#include <asm/asm.h>
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#include <asm/export.h>
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/* rdi: arg1 ... normal C conventions. rax is saved/restored. */
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.macro THUNK name, func
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SYM_FUNC_START(\name)
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pushq %rbp
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movq %rsp, %rbp
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pushq %rdi
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pushq %rsi
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pushq %rdx
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pushq %rcx
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pushq %rax
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pushq %r8
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pushq %r9
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pushq %r10
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pushq %r11
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call \func
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popq %r11
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popq %r10
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popq %r9
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popq %r8
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popq %rax
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popq %rcx
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popq %rdx
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popq %rsi
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popq %rdi
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popq %rbp
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RET
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SYM_FUNC_END(\name)
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_ASM_NOKPROBE(\name)
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.endm
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THUNK preempt_schedule_thunk, preempt_schedule
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THUNK preempt_schedule_notrace_thunk, preempt_schedule_notrace
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EXPORT_SYMBOL(preempt_schedule_thunk)
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EXPORT_SYMBOL(preempt_schedule_notrace_thunk)
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