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ef64789413
The linker should not be adding holes to word size aligned pointers, but out of paranoia we are explicitly specifying that alignment. I have not seen any holes in the jump label section in practice. Signed-off-by: Jason Baron <jbaron@redhat.com> LKML-Reference: <e119fbd060c9452c56063ea6148ba1070e7434cc.1300299760.git.jbaron@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
43 lines
753 B
C
43 lines
753 B
C
#ifndef _ASM_X86_JUMP_LABEL_H
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#define _ASM_X86_JUMP_LABEL_H
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#ifdef __KERNEL__
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#include <linux/types.h>
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#include <asm/nops.h>
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#include <asm/asm.h>
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#define JUMP_LABEL_NOP_SIZE 5
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#define JUMP_LABEL_INITIAL_NOP ".byte 0xe9 \n\t .long 0\n\t"
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static __always_inline bool arch_static_branch(struct jump_label_key *key)
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{
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asm goto("1:"
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JUMP_LABEL_INITIAL_NOP
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".pushsection __jump_table, \"aw\" \n\t"
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_ASM_ALIGN "\n\t"
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_ASM_PTR "1b, %l[l_yes], %c0 \n\t"
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".popsection \n\t"
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: : "i" (key) : : l_yes);
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return false;
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l_yes:
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return true;
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}
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#endif /* __KERNEL__ */
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#ifdef CONFIG_X86_64
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typedef u64 jump_label_t;
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#else
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typedef u32 jump_label_t;
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#endif
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struct jump_entry {
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jump_label_t code;
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jump_label_t target;
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jump_label_t key;
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};
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#endif
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