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| author | Oleg Nesterov <oleg@redhat.com> | 2012-11-24 18:27:08 +0100 |
|---|---|---|
| committer | Oleg Nesterov <oleg@redhat.com> | 2013-02-08 17:47:06 +0100 |
| commit | bb929284be40cbbdb347690742557d708fd504a9 (patch) | |
| tree | 6f86aba2f415508fdccb88804bc03bdae3a0e160 /kernel | |
| parent | uprobes: Change filter_chain() to iterate ->consumers list (diff) | |
| download | linux-bb929284be40cbbdb347690742557d708fd504a9.tar.xz linux-bb929284be40cbbdb347690742557d708fd504a9.zip | |
uprobes: Kill UPROBE_RUN_HANDLER flag
Simply remove UPROBE_RUN_HANDLER and the corresponding code.
It can only help if uprobe has a single consumer, and in fact
it is no longer needed after handler_chain() was changed to use
->register_rwsem, we simply can not race with uprobe_register().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Diffstat (limited to '')
| -rw-r--r-- | kernel/events/uprobes.c | 23 |
1 files changed, 5 insertions, 18 deletions
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 4d0452363686..7ec2eb278634 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -83,10 +83,8 @@ static atomic_t uprobe_events = ATOMIC_INIT(0); /* Have a copy of original instruction */ #define UPROBE_COPY_INSN 0 -/* Dont run handlers when first register/ last unregister in progress*/ -#define UPROBE_RUN_HANDLER 1 /* Can skip singlestep */ -#define UPROBE_SKIP_SSTEP 2 +#define UPROBE_SKIP_SSTEP 1 struct uprobe { struct rb_node rb_node; /* node in the rb tree */ @@ -475,9 +473,6 @@ static void handler_chain(struct uprobe *uprobe, struct pt_regs *regs) { struct uprobe_consumer *uc; - if (!test_bit(UPROBE_RUN_HANDLER, &uprobe->flags)) - return; - down_read(&uprobe->register_rwsem); for (uc = uprobe->consumers; uc; uc = uc->next) uc->handler(uc, regs); @@ -825,13 +820,8 @@ static int register_for_each_vma(struct uprobe *uprobe, bool is_register) static int __uprobe_register(struct uprobe *uprobe, struct uprobe_consumer *uc) { - int err; - consumer_add(uprobe, uc); - err = register_for_each_vma(uprobe, true); - if (!err) /* TODO: pointless unless the first consumer */ - set_bit(UPROBE_RUN_HANDLER, &uprobe->flags); - return err; + return register_for_each_vma(uprobe, true); } static void __uprobe_unregister(struct uprobe *uprobe, struct uprobe_consumer *uc) @@ -842,12 +832,9 @@ static void __uprobe_unregister(struct uprobe *uprobe, struct uprobe_consumer *u return; err = register_for_each_vma(uprobe, false); - if (!uprobe->consumers) { - clear_bit(UPROBE_RUN_HANDLER, &uprobe->flags); - /* TODO : cant unregister? schedule a worker thread */ - if (!err) - delete_uprobe(uprobe); - } + /* TODO : cant unregister? schedule a worker thread */ + if (!uprobe->consumers && !err) + delete_uprobe(uprobe); } /* |