From: Michael Tirado <mtirado418@gmail.com>
To: Kees Cook <keescook@chromium.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: Re: eBPF / seccomp globals?
Date: Thu, 10 Sep 2015 23:22:23 +0000 [thread overview]
Message-ID: <CAMkWEXMm=vRoxyzfODQsg9kvMfYs9ENw=dn+2cvPMP-i7_WzZg@mail.gmail.com> (raw)
In-Reply-To: <CAMkWEXM2pyuOx8VhGLQUQU=7jLuB4ifNydu4egK2k-HnWf6h1w@mail.gmail.com>
Sorry for spamming you guys with my ugly, poorly formatted hack.
I had to change something due to my shallow knowledge of how
multiprocessors / multiple threads sharing a filter would behave.
There may have been a possibility for the deferred integer to rollover
and ruin everything? just in case someone tries to use it....
From: Michael R Tirado <mtirado418@gmail.com>
Date: Thu, 10 Sep 2015 23:06:55 +0000
Subject: [PATCH 2/2] changed to signed integer, due to multiprocesor
uncertainty.
---
kernel/seccomp.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index dc2a5af..e39e8c2 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -58,7 +58,7 @@ struct seccomp_filter {
atomic_t usage;
struct seccomp_filter *prev;
struct bpf_prog *prog;
- unsigned int deferred;
+ int deferred;
};
/* Limit any path through the tree to 256KB worth of instructions. */
@@ -198,7 +198,7 @@ static u32 seccomp_run_filters(struct seccomp_data *sd)
*/
for (; f; f = f->prev) {
u32 cur_ret;
- if (unlikely(f->deferred)) {
+ if (unlikely(f->deferred > 0)) {
--f->deferred;
continue;
}
--
1.8.4
next prev parent reply other threads:[~2015-09-10 23:22 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-04 1:01 eBPF / seccomp globals? Michael Tirado
2015-09-04 3:17 ` Alexei Starovoitov
2015-09-04 14:03 ` Tycho Andersen
2015-09-04 4:01 ` Kees Cook
2015-09-04 20:29 ` Michael Tirado
2015-09-04 20:37 ` Kees Cook
2015-09-10 21:55 ` Michael Tirado
2015-09-10 23:22 ` Michael Tirado [this message]
2015-09-29 23:44 ` Kees Cook
2015-09-30 0:07 ` Andy Lutomirski
2015-10-06 16:00 ` Michael Tirado
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