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From a1ca3c314c8269850db5f1417ea2dfd9a254e10b Mon Sep 17 00:00:00 2001 |
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From: Masami Hiramatsu <mhiramat@kernel.org> |
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Date: Tue, 11 Sep 2018 19:20:40 +0900 |
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Subject: [PATCH 059/145] kprobes: Return error if we fail to reuse kprobe |
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instead of BUG_ON() |
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|
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[ Upstream commit 819319fc93461c07b9cdb3064f154bd8cfd48172 ] |
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|
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Make reuse_unused_kprobe() to return error code if |
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it fails to reuse unused kprobe for optprobe instead |
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of calling BUG_ON(). |
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|
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Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> |
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Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> |
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Cc: David S . Miller <davem@davemloft.net> |
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Cc: Linus Torvalds <torvalds@linux-foundation.org> |
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Cc: Naveen N . Rao <naveen.n.rao@linux.vnet.ibm.com> |
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Cc: Peter Zijlstra <peterz@infradead.org> |
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Cc: Thomas Gleixner <tglx@linutronix.de> |
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Link: http://lkml.kernel.org/r/153666124040.21306.14150398706331307654.stgit@devbox |
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Signed-off-by: Ingo Molnar <mingo@kernel.org> |
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Signed-off-by: Sasha Levin <sashal@kernel.org> |
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--- |
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kernel/kprobes.c | 27 ++++++++++++++++++++------- |
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1 file changed, 20 insertions(+), 7 deletions(-) |
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|
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diff --git a/kernel/kprobes.c b/kernel/kprobes.c |
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index ab257be4d924..4344381664cc 100644 |
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--- a/kernel/kprobes.c |
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+++ b/kernel/kprobes.c |
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@@ -700,9 +700,10 @@ static void unoptimize_kprobe(struct kprobe *p, bool force) |
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} |
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|
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/* Cancel unoptimizing for reusing */ |
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-static void reuse_unused_kprobe(struct kprobe *ap) |
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+static int reuse_unused_kprobe(struct kprobe *ap) |
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{ |
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struct optimized_kprobe *op; |
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+ int ret; |
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|
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BUG_ON(!kprobe_unused(ap)); |
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/* |
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@@ -714,8 +715,12 @@ static void reuse_unused_kprobe(struct kprobe *ap) |
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/* Enable the probe again */ |
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ap->flags &= ~KPROBE_FLAG_DISABLED; |
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/* Optimize it again (remove from op->list) */ |
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- BUG_ON(!kprobe_optready(ap)); |
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+ ret = kprobe_optready(ap); |
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+ if (ret) |
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+ return ret; |
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+ |
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optimize_kprobe(ap); |
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+ return 0; |
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} |
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|
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/* Remove optimized instructions */ |
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@@ -940,11 +945,16 @@ static void __disarm_kprobe(struct kprobe *p, bool reopt) |
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#define kprobe_disarmed(p) kprobe_disabled(p) |
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#define wait_for_kprobe_optimizer() do {} while (0) |
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|
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-/* There should be no unused kprobes can be reused without optimization */ |
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-static void reuse_unused_kprobe(struct kprobe *ap) |
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+static int reuse_unused_kprobe(struct kprobe *ap) |
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{ |
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+ /* |
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+ * If the optimized kprobe is NOT supported, the aggr kprobe is |
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+ * released at the same time that the last aggregated kprobe is |
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+ * unregistered. |
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+ * Thus there should be no chance to reuse unused kprobe. |
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+ */ |
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printk(KERN_ERR "Error: There should be no unused kprobe here.\n"); |
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- BUG_ON(kprobe_unused(ap)); |
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+ return -EINVAL; |
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} |
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|
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static void free_aggr_kprobe(struct kprobe *p) |
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@@ -1318,9 +1328,12 @@ static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p) |
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goto out; |
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} |
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init_aggr_kprobe(ap, orig_p); |
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- } else if (kprobe_unused(ap)) |
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+ } else if (kprobe_unused(ap)) { |
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/* This probe is going to die. Rescue it */ |
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- reuse_unused_kprobe(ap); |
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+ ret = reuse_unused_kprobe(ap); |
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+ if (ret) |
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+ goto out; |
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+ } |
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|
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if (kprobe_gone(ap)) { |
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/* |
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-- |
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2.19.1 |
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