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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-12 14:21:15 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-12 14:21:15 -0700 |
commit | 1c6890707eb1438b0fb4e0a10d4afe48a217628b (patch) | |
tree | f600dc002e5076353efb005727d2fa3c47560dd4 /arch/arc | |
parent | 3bff6112c80cecb76af5fe485506f96e8adb6122 (diff) | |
parent | bcb53209be5cb32d485507452edda19b78f31d84 (diff) | |
download | linux-1c6890707eb1438b0fb4e0a10d4afe48a217628b.tar.gz linux-1c6890707eb1438b0fb4e0a10d4afe48a217628b.tar.bz2 linux-1c6890707eb1438b0fb4e0a10d4afe48a217628b.zip |
Merge tag 'perf-kprobes-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf/kprobes updates from Ingo Molnar:
"This prepares to unify the kretprobe trampoline handler and make
kretprobe lockless (those patches are still work in progress)"
* tag 'perf-kprobes-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
kprobes: Fix to check probe enabled before disarm_kprobe_ftrace()
kprobes: Make local functions static
kprobes: Free kretprobe_instance with RCU callback
kprobes: Remove NMI context check
sparc: kprobes: Use generic kretprobe trampoline handler
sh: kprobes: Use generic kretprobe trampoline handler
s390: kprobes: Use generic kretprobe trampoline handler
powerpc: kprobes: Use generic kretprobe trampoline handler
parisc: kprobes: Use generic kretprobe trampoline handler
mips: kprobes: Use generic kretprobe trampoline handler
ia64: kprobes: Use generic kretprobe trampoline handler
csky: kprobes: Use generic kretprobe trampoline handler
arc: kprobes: Use generic kretprobe trampoline handler
arm64: kprobes: Use generic kretprobe trampoline handler
arm: kprobes: Use generic kretprobe trampoline handler
x86/kprobes: Use generic kretprobe trampoline handler
kprobes: Add generic kretprobe trampoline handler
Diffstat (limited to 'arch/arc')
-rw-r--r-- | arch/arc/kernel/kprobes.c | 54 |
1 files changed, 2 insertions, 52 deletions
diff --git a/arch/arc/kernel/kprobes.c b/arch/arc/kernel/kprobes.c index 7d3efe83cba7..cabef45f11df 100644 --- a/arch/arc/kernel/kprobes.c +++ b/arch/arc/kernel/kprobes.c @@ -388,6 +388,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, { ri->ret_addr = (kprobe_opcode_t *) regs->blink; + ri->fp = NULL; /* Replace the return addr with trampoline addr */ regs->blink = (unsigned long)&kretprobe_trampoline; @@ -396,58 +397,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, static int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { - struct kretprobe_instance *ri = NULL; - struct hlist_head *head, empty_rp; - struct hlist_node *tmp; - unsigned long flags, orig_ret_address = 0; - unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline; - - INIT_HLIST_HEAD(&empty_rp); - kretprobe_hash_lock(current, &head, &flags); - - /* - * It is possible to have multiple instances associated with a given - * task either because an multiple functions in the call path - * have a return probe installed on them, and/or more than one return - * return probe was registered for a target function. - * - * We can handle this because: - * - instances are always inserted at the head of the list - * - when multiple return probes are registered for the same - * function, the first instance's ret_addr will point to the - * real return address, and all the rest will point to - * kretprobe_trampoline - */ - hlist_for_each_entry_safe(ri, tmp, head, hlist) { - if (ri->task != current) - /* another task is sharing our hash bucket */ - continue; - - if (ri->rp && ri->rp->handler) - ri->rp->handler(ri, regs); - - orig_ret_address = (unsigned long)ri->ret_addr; - recycle_rp_inst(ri, &empty_rp); - - if (orig_ret_address != trampoline_address) { - /* - * This is the real return address. Any other - * instances associated with this task are for - * other calls deeper on the call stack - */ - break; - } - } - - kretprobe_assert(ri, orig_ret_address, trampoline_address); - regs->ret = orig_ret_address; - - kretprobe_hash_unlock(current, &flags); - - hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { - hlist_del(&ri->hlist); - kfree(ri); - } + regs->ret = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); /* By returning a non zero value, we are telling the kprobe handler * that we don't want the post_handler to run |