bcc/SOURCES/bcc-0.25.0-tools-nfsslower.py-Fix-uninitialized-struct-pad-erro.patch

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From 1d8419056e128ae49107d27e5f55d1bfa8134e3a Mon Sep 17 00:00:00 2001
From: Rong Tao <rongtao@cestc.cn>
Date: Fri, 10 Feb 2023 22:16:56 +0800
Subject: [PATCH] tools/nfsslower.py: Fix uninitialized struct pad error
The verifier is unhappy, if data struct _pad_ is not initialized, see [0][1].
$ sudo ./nfsslower.py
...
; bpf_perf_event_output(ctx, (void *)bpf_pseudo_fd(1, -2), CUR_CPU_IDENTIFIER, &data, sizeof(data));
83: (79) r1 = *(u64 *)(r10 -144) ; R1_w=ctx(off=0,imm=0) R10=fp0
84: (18) r3 = 0xffffffff ; R3_w=4294967295
86: (b7) r5 = 96 ; R5_w=96
87: (85) call bpf_perf_event_output#25
invalid indirect read from stack R4 off -136+92 size 96
processed 84 insns (limit 1000000) max_states_per_insn 0 total_states 4 peak_states 4 mark_read 4
...
raise Exception("Failed to load BPF program %s: %s" %
Exception: Failed to load BPF program b'raw_tracepoint__nfs_commit_done': Permission denied
[0] https://github.com/iovisor/bcc/issues/2623
[1] https://github.com/iovisor/bcc/pull/4453
Signed-off-by: Rong Tao <rongtao@cestc.cn>
---
tools/nfsslower.py | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/tools/nfsslower.py b/tools/nfsslower.py
index b5df8f19..c2c243b3 100755
--- a/tools/nfsslower.py
+++ b/tools/nfsslower.py
@@ -179,8 +179,11 @@ static int trace_exit(struct pt_regs *ctx, int type)
// populate output struct
u32 size = PT_REGS_RC(ctx);
- struct data_t data = {.type = type, .size = size, .delta_us = delta_us,
- .pid = pid};
+ struct data_t data = {};
+ data.type = type;
+ data.size = size;
+ data.delta_us = delta_us;
+ data.pid = pid;
data.ts_us = ts / 1000;
data.offset = valp->offset;
bpf_get_current_comm(&data.task, sizeof(data.task));
--
2.40.1