summaryrefslogtreecommitdiff
path: root/tools/perf/util/bpf-prologue.h
blob: d94cbea128999aab4368404140b07a0755ba4439 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
/*
 * Copyright (C) 2015, He Kuang <hekuang@huawei.com>
 * Copyright (C) 2015, Huawei Inc.
 */
#ifndef __BPF_PROLOGUE_H
#define __BPF_PROLOGUE_H

#include <linux/compiler.h>
#include <linux/filter.h>
#include "probe-event.h"

#define BPF_PROLOGUE_MAX_ARGS 3
#define BPF_PROLOGUE_START_ARG_REG BPF_REG_3
#define BPF_PROLOGUE_FETCH_RESULT_REG BPF_REG_2

#ifdef HAVE_BPF_PROLOGUE
int bpf__gen_prologue(struct probe_trace_arg *args, int nargs,
		      struct bpf_insn *new_prog, size_t *new_cnt,
		      size_t cnt_space);
#else
static inline int
bpf__gen_prologue(struct probe_trace_arg *args __maybe_unused,
		  int nargs __maybe_unused,
		  struct bpf_insn *new_prog __maybe_unused,
		  size_t *new_cnt,
		  size_t cnt_space __maybe_unused)
{
	if (!new_cnt)
		return -EINVAL;
	*new_cnt = 0;
	return -ENOTSUP;
}
#endif
#endif /* __BPF_PROLOGUE_H */
tr>parent191e885a2e130e639bb0c8ee350d7047294f2ce6 (diff)
Drivers: hv: vmbus: finally fix hv_need_to_signal_on_read()
Commit a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in hv_need_to_signal_on_read()") added the proper mb(), but removed the test "prev_write_sz < pending_sz" when making the signal decision. As a result, the guest can signal the host unnecessarily, and then the host can throttle the guest because the host thinks the guest is buggy or malicious; finally the user running stress test can perceive intermittent freeze of the guest. This patch brings back the test, and properly handles the in-place consumption APIs used by NetVSC (see get_next_pkt_raw(), put_pkt_raw() and commit_rd_index()). Fixes: a389fcfd2cb5 ("Drivers: hv: vmbus: Fix signaling logic in hv_need_to_signal_on_read()") Signed-off-by: Dexuan Cui <decui@microsoft.com> Reported-by: Rolf Neugebauer <rolf.neugebauer@docker.com> Tested-by: Rolf Neugebauer <rolf.neugebauer@docker.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: <stable@vger.kernel.org> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools/perf/pmu-events/README')