summaryrefslogtreecommitdiff
path: root/include/linux/perf_event.h
diff options
context:
space:
mode:
authorDaniel Borkmann <daniel@iogearbox.net>2016-07-22 02:19:42 +0300
committerDavid S. Miller <davem@davemloft.net>2016-07-25 20:34:11 +0300
commitaa7145c16d6bf086538ad7eb20c807513bfa5efc (patch)
treedbaccc895163a74c9b87c71eeff8c1f59d4f2a9e /include/linux/perf_event.h
parenta1b43eddaec5a3fea55e1581caf217abda2d3147 (diff)
downloadlinux-aa7145c16d6bf086538ad7eb20c807513bfa5efc.tar.xz
bpf, events: fix offset in skb copy handler
This patch fixes the __output_custom() routine we currently use with bpf_skb_copy(). I missed that when len is larger than the size of the current handle, we can issue multiple invocations of copy_func, and __output_custom() advances destination but also source buffer by the written amount of bytes. When we have __output_custom(), this is actually wrong since in that case the source buffer points to a non-linear object, in our case an skb, which the copy_func helper is supposed to walk. Therefore, since this is non-linear we thus need to pass the offset into the helper, so that copy_func can use it for extracting the data from the source object. Therefore, adjust the callback signatures properly and pass offset into the skb_header_pointer() invoked from bpf_skb_copy() callback. The __DEFINE_OUTPUT_COPY_BODY() is adjusted to accommodate for two things: i) to pass in whether we should advance source buffer or not; this is a compile-time constant condition, ii) to pass in the offset for __output_custom(), which we do with help of __VA_ARGS__, so everything can stay inlined as is currently. Both changes allow for adapting the __output_* fast-path helpers w/o extra overhead. Fixes: 555c8a8623a3 ("bpf: avoid stack copy and use skb ctx for event output") Fixes: 7e3f977edd0b ("perf, events: add non-linear data support for raw records") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/perf_event.h')
-rw-r--r--include/linux/perf_event.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index e79e6c6fed89..15e55b7ee096 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -70,7 +70,7 @@ struct perf_callchain_entry_ctx {
};
typedef unsigned long (*perf_copy_f)(void *dst, const void *src,
- unsigned long len);
+ unsigned long off, unsigned long len);
struct perf_raw_frag {
union {