jump_label: Rename JUMP_LABEL_{EN,DIS}ABLE to JUMP_LABEL_{JMP,NOP}
Since we've already stepped away from ENABLE is a JMP and DISABLE is a
NOP with the branch_default bits, and are going to make it even worse,
rename it to make it all clearer.
This way we don't mix multiple levels of logic attributes, but have a
plain 'physical' name for what the current instruction patching status
of a jump label is.
This is a first step in removing the naming confusion that has led to
a stream of avoidable bugs such as:
a833581e37
("x86, perf: Fix static_key bug in load_mm_cr4()")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
[ Beefed up the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
parent
f320ead76a
commit
76b235c6bc
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@ -12,7 +12,7 @@ static void __arch_jump_label_transform(struct jump_entry *entry,
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void *addr = (void *)entry->code;
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void *addr = (void *)entry->code;
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unsigned int insn;
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unsigned int insn;
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if (type == JUMP_LABEL_ENABLE)
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if (type == JUMP_LABEL_JMP)
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insn = arm_gen_branch(entry->code, entry->target);
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insn = arm_gen_branch(entry->code, entry->target);
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else
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else
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insn = arm_gen_nop();
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insn = arm_gen_nop();
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@ -28,7 +28,7 @@ void arch_jump_label_transform(struct jump_entry *entry,
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void *addr = (void *)entry->code;
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void *addr = (void *)entry->code;
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u32 insn;
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u32 insn;
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if (type == JUMP_LABEL_ENABLE) {
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if (type == JUMP_LABEL_JMP) {
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insn = aarch64_insn_gen_branch_imm(entry->code,
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insn = aarch64_insn_gen_branch_imm(entry->code,
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entry->target,
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entry->target,
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AARCH64_INSN_BRANCH_NOLINK);
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AARCH64_INSN_BRANCH_NOLINK);
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@ -51,7 +51,7 @@ void arch_jump_label_transform(struct jump_entry *e,
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/* Target must have the right alignment and ISA must be preserved. */
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/* Target must have the right alignment and ISA must be preserved. */
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BUG_ON((e->target & J_ALIGN_MASK) != J_ISA_BIT);
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BUG_ON((e->target & J_ALIGN_MASK) != J_ISA_BIT);
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if (type == JUMP_LABEL_ENABLE) {
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if (type == JUMP_LABEL_JMP) {
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insn.j_format.opcode = J_ISA_BIT ? mm_j32_op : j_op;
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insn.j_format.opcode = J_ISA_BIT ? mm_j32_op : j_op;
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insn.j_format.target = e->target >> J_RANGE_SHIFT;
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insn.j_format.target = e->target >> J_RANGE_SHIFT;
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} else {
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} else {
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@ -17,7 +17,7 @@ void arch_jump_label_transform(struct jump_entry *entry,
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{
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{
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u32 *addr = (u32 *)(unsigned long)entry->code;
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u32 *addr = (u32 *)(unsigned long)entry->code;
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if (type == JUMP_LABEL_ENABLE)
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if (type == JUMP_LABEL_JMP)
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patch_branch(addr, entry->target, 0);
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patch_branch(addr, entry->target, 0);
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else
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else
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patch_instruction(addr, PPC_INST_NOP);
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patch_instruction(addr, PPC_INST_NOP);
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@ -64,7 +64,7 @@ static void __jump_label_transform(struct jump_entry *entry,
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{
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{
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struct insn old, new;
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struct insn old, new;
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if (type == JUMP_LABEL_ENABLE) {
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if (type == JUMP_LABEL_JMP) {
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jump_label_make_nop(entry, &old);
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jump_label_make_nop(entry, &old);
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jump_label_make_branch(entry, &new);
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jump_label_make_branch(entry, &new);
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} else {
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} else {
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@ -16,7 +16,7 @@ void arch_jump_label_transform(struct jump_entry *entry,
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u32 val;
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u32 val;
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u32 *insn = (u32 *) (unsigned long) entry->code;
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u32 *insn = (u32 *) (unsigned long) entry->code;
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if (type == JUMP_LABEL_ENABLE) {
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if (type == JUMP_LABEL_JMP) {
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s32 off = (s32)entry->target - (s32)entry->code;
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s32 off = (s32)entry->target - (s32)entry->code;
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#ifdef CONFIG_SPARC64
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#ifdef CONFIG_SPARC64
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@ -45,7 +45,7 @@ static void __jump_label_transform(struct jump_entry *entry,
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const unsigned char default_nop[] = { STATIC_KEY_INIT_NOP };
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const unsigned char default_nop[] = { STATIC_KEY_INIT_NOP };
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const unsigned char *ideal_nop = ideal_nops[NOP_ATOMIC5];
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const unsigned char *ideal_nop = ideal_nops[NOP_ATOMIC5];
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if (type == JUMP_LABEL_ENABLE) {
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if (type == JUMP_LABEL_JMP) {
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if (init) {
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if (init) {
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/*
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/*
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* Jump label is enabled for the first time.
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* Jump label is enabled for the first time.
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@ -86,8 +86,8 @@ struct static_key {
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#ifndef __ASSEMBLY__
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#ifndef __ASSEMBLY__
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enum jump_label_type {
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enum jump_label_type {
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JUMP_LABEL_DISABLE = 0,
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JUMP_LABEL_NOP = 0,
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JUMP_LABEL_ENABLE,
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JUMP_LABEL_JMP,
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};
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};
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struct module;
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struct module;
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@ -65,9 +65,9 @@ void static_key_slow_inc(struct static_key *key)
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jump_label_lock();
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jump_label_lock();
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if (atomic_read(&key->enabled) == 0) {
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if (atomic_read(&key->enabled) == 0) {
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if (!jump_label_get_branch_default(key))
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if (!jump_label_get_branch_default(key))
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jump_label_update(key, JUMP_LABEL_ENABLE);
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jump_label_update(key, JUMP_LABEL_JMP);
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else
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else
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jump_label_update(key, JUMP_LABEL_DISABLE);
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jump_label_update(key, JUMP_LABEL_NOP);
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}
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}
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atomic_inc(&key->enabled);
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atomic_inc(&key->enabled);
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jump_label_unlock();
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jump_label_unlock();
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@ -88,9 +88,9 @@ static void __static_key_slow_dec(struct static_key *key,
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schedule_delayed_work(work, rate_limit);
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schedule_delayed_work(work, rate_limit);
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} else {
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} else {
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if (!jump_label_get_branch_default(key))
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if (!jump_label_get_branch_default(key))
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jump_label_update(key, JUMP_LABEL_DISABLE);
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jump_label_update(key, JUMP_LABEL_NOP);
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else
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else
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jump_label_update(key, JUMP_LABEL_ENABLE);
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jump_label_update(key, JUMP_LABEL_JMP);
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}
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}
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jump_label_unlock();
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jump_label_unlock();
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}
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}
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@ -184,9 +184,9 @@ static enum jump_label_type jump_label_type(struct static_key *key)
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bool state = static_key_enabled(key);
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bool state = static_key_enabled(key);
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if ((!true_branch && state) || (true_branch && !state))
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if ((!true_branch && state) || (true_branch && !state))
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return JUMP_LABEL_ENABLE;
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return JUMP_LABEL_JMP;
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return JUMP_LABEL_DISABLE;
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return JUMP_LABEL_NOP;
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}
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}
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void __init jump_label_init(void)
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void __init jump_label_init(void)
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@ -276,7 +276,7 @@ void jump_label_apply_nops(struct module *mod)
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return;
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return;
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for (iter = iter_start; iter < iter_stop; iter++) {
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for (iter = iter_start; iter < iter_stop; iter++) {
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arch_jump_label_transform_static(iter, JUMP_LABEL_DISABLE);
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arch_jump_label_transform_static(iter, JUMP_LABEL_NOP);
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}
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}
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}
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}
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@ -318,8 +318,8 @@ static int jump_label_add_module(struct module *mod)
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jlm->next = key->next;
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jlm->next = key->next;
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key->next = jlm;
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key->next = jlm;
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if (jump_label_type(key) == JUMP_LABEL_ENABLE)
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if (jump_label_type(key) == JUMP_LABEL_JMP)
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__jump_label_update(key, iter, iter_stop, JUMP_LABEL_ENABLE);
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__jump_label_update(key, iter, iter_stop, JUMP_LABEL_JMP);
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}
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}
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return 0;
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return 0;
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