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authorMauro Carvalho Chehab <mchehab@osg.samsung.com>2015-04-21 11:33:03 +0200
committerMauro Carvalho Chehab <mchehab@osg.samsung.com>2015-04-21 14:44:55 +0200
commit64131a87f2aae2ed9e05d8227c5b009ca6c50d98 (patch)
treefdea23fd59216120bf54a48c60ca24489a733f14 /samples/bpf/tracex1_kern.c
parentMerge branch 'patchwork' into v4l_for_linus (diff)
parentMerge Linus master into drm-next (diff)
downloadlinux-64131a87f2aae2ed9e05d8227c5b009ca6c50d98.tar.xz
linux-64131a87f2aae2ed9e05d8227c5b009ca6c50d98.zip
Merge branch 'drm-next-merged' of git://people.freedesktop.org/~airlied/linux into v4l_for_linus
* 'drm-next-merged' of git://people.freedesktop.org/~airlied/linux: (9717 commits) media-bus: Fixup RGB444_1X12, RGB565_1X16, and YUV8_1X24 media bus format hexdump: avoid warning in test function fs: take i_mutex during prepare_binprm for set[ug]id executables smp: Fix error case handling in smp_call_function_*() iommu-common: Fix PARISC compile-time warnings sparc: Make LDC use common iommu poll management functions sparc: Make sparc64 use scalable lib/iommu-common.c functions Break up monolithic iommu table/lock into finer graularity pools and lock sparc: Revert generic IOMMU allocator. tools/power turbostat: correct dumped pkg-cstate-limit value tools/power turbostat: calculate TSC frequency from CPUID(0x15) on SKL tools/power turbostat: correct DRAM RAPL units on recent Xeon processors tools/power turbostat: Initial Skylake support tools/power turbostat: Use $(CURDIR) instead of $(PWD) and add support for O= option in Makefile tools/power turbostat: modprobe msr, if needed tools/power turbostat: dump MSR_TURBO_RATIO_LIMIT2 tools/power turbostat: use new MSR_TURBO_RATIO_LIMIT names Bluetooth: hidp: Fix regression with older userspace and flags validation config: Enable NEED_DMA_MAP_STATE by default when SWIOTLB is selected perf/x86/intel/pt: Fix and clean up error handling in pt_event_add() ... That solves several merge conflicts: Documentation/DocBook/media/v4l/subdev-formats.xml Documentation/devicetree/bindings/vendor-prefixes.txt drivers/staging/media/mn88473/mn88473.c include/linux/kconfig.h include/uapi/linux/media-bus-format.h The ones at subdev-formats.xml and media-bus-format.h are not trivial. That's why we opted to merge from DRM.
Diffstat (limited to 'samples/bpf/tracex1_kern.c')
-rw-r--r--samples/bpf/tracex1_kern.c50
1 files changed, 50 insertions, 0 deletions
diff --git a/samples/bpf/tracex1_kern.c b/samples/bpf/tracex1_kern.c
new file mode 100644
index 000000000000..31620463701a
--- /dev/null
+++ b/samples/bpf/tracex1_kern.c
@@ -0,0 +1,50 @@
+/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <uapi/linux/bpf.h>
+#include <linux/version.h>
+#include "bpf_helpers.h"
+
+#define _(P) ({typeof(P) val = 0; bpf_probe_read(&val, sizeof(val), &P); val;})
+
+/* kprobe is NOT a stable ABI
+ * kernel functions can be removed, renamed or completely change semantics.
+ * Number of arguments and their positions can change, etc.
+ * In such case this bpf+kprobe example will no longer be meaningful
+ */
+SEC("kprobe/__netif_receive_skb_core")
+int bpf_prog1(struct pt_regs *ctx)
+{
+ /* attaches to kprobe netif_receive_skb,
+ * looks for packets on loobpack device and prints them
+ */
+ char devname[IFNAMSIZ] = {};
+ struct net_device *dev;
+ struct sk_buff *skb;
+ int len;
+
+ /* non-portable! works for the given kernel only */
+ skb = (struct sk_buff *) ctx->di;
+
+ dev = _(skb->dev);
+
+ len = _(skb->len);
+
+ bpf_probe_read(devname, sizeof(devname), dev->name);
+
+ if (devname[0] == 'l' && devname[1] == 'o') {
+ char fmt[] = "skb %p len %d\n";
+ /* using bpf_trace_printk() for DEBUG ONLY */
+ bpf_trace_printk(fmt, sizeof(fmt), skb, len);
+ }
+
+ return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;