91bad2f8d3
register_kprobe() downs the 'text_mutex' and then calls jump_label_text_reserved(), which downs the 'jump_label_mutex'. However, the jump label code takes those mutexes in the reverse order. Fix by requiring the caller of jump_label_text_reserved() to do the jump label locking via the newly added: jump_label_lock(), jump_label_unlock(). Currently, kprobes is the only user of jump_label_text_reserved(). Reported-by: Ingo Molnar <mingo@elte.hu> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Jason Baron <jbaron@redhat.com> LKML-Reference: <759032c48d5e30c27f0bba003d09bffa8e9f28bb.1285965957.git.jbaron@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
79 lines
1.7 KiB
C
79 lines
1.7 KiB
C
#ifndef _LINUX_JUMP_LABEL_H
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#define _LINUX_JUMP_LABEL_H
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#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_HAVE_ARCH_JUMP_LABEL)
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# include <asm/jump_label.h>
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# define HAVE_JUMP_LABEL
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#endif
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enum jump_label_type {
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JUMP_LABEL_ENABLE,
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JUMP_LABEL_DISABLE
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};
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struct module;
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#ifdef HAVE_JUMP_LABEL
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extern struct jump_entry __start___jump_table[];
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extern struct jump_entry __stop___jump_table[];
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extern void jump_label_lock(void);
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extern void jump_label_unlock(void);
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extern void arch_jump_label_transform(struct jump_entry *entry,
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enum jump_label_type type);
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extern void arch_jump_label_text_poke_early(jump_label_t addr);
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extern void jump_label_update(unsigned long key, enum jump_label_type type);
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extern void jump_label_apply_nops(struct module *mod);
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extern int jump_label_text_reserved(void *start, void *end);
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#define jump_label_enable(key) \
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jump_label_update((unsigned long)key, JUMP_LABEL_ENABLE);
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#define jump_label_disable(key) \
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jump_label_update((unsigned long)key, JUMP_LABEL_DISABLE);
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#else
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#define JUMP_LABEL(key, label) \
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do { \
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if (unlikely(*key)) \
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goto label; \
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} while (0)
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#define jump_label_enable(cond_var) \
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do { \
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*(cond_var) = 1; \
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} while (0)
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#define jump_label_disable(cond_var) \
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do { \
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*(cond_var) = 0; \
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} while (0)
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static inline int jump_label_apply_nops(struct module *mod)
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{
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return 0;
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}
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static inline int jump_label_text_reserved(void *start, void *end)
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{
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return 0;
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}
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static inline void jump_label_lock(void) {}
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static inline void jump_label_unlock(void) {}
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#endif
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#define COND_STMT(key, stmt) \
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do { \
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__label__ jl_enabled; \
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JUMP_LABEL(key, jl_enabled); \
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if (0) { \
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jl_enabled: \
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stmt; \
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} \
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} while (0)
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#endif
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