51 lines
2.0 KiB
Diff
51 lines
2.0 KiB
Diff
From 3f7b59660037c0d5dea785d115df25d9b95f07dc Mon Sep 17 00:00:00 2001
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From: Xiaozhou Liu <liuxiaozhou@bytedance.com>
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Date: Mon, 21 Jan 2019 11:23:42 +0800
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Subject: [PATCH] print_log2_hist(): check and skip possible paddings (#2155)
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Address issue 2154.
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When a struct S is used as key to a BPF_HISTOGRAM, it is assumed that the second
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member of S holds the slot. But when S is converted to python from bpf C,
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a padding may be inserted as a second member. This breaks print_log2_hist().
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root@debian:~/bcc/tools# ./softirqs.py -d
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Tracing soft irq event time... Hit Ctrl-C to end.
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^C
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Traceback (most recent call last):
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File "./softirqs.py", line 144, in <module>
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dist.print_log2_hist(label, "softirq", section_print_fn=vec_to_name)
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File "/usr/local/lib/python2.7/dist-packages/bcc/table.py", line 326, in print_log2_hist
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vals[slot] = v.value
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TypeError: list indices must be integers, not str
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Fix it by skipping the possible padding. Future work would be fixing/working
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around in the library where the padding is introduced.
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---
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src/python/bcc/table.py | 9 +++++++++
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1 file changed, 9 insertions(+)
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diff --git a/src/python/bcc/table.py b/src/python/bcc/table.py
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index 6f598353..f6449de7 100644
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--- a/src/python/bcc/table.py
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+++ b/src/python/bcc/table.py
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@@ -317,6 +317,15 @@ linear_index_max = 1025
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tmp = {}
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f1 = self.Key._fields_[0][0]
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f2 = self.Key._fields_[1][0]
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+
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+ # The above code assumes that self.Key._fields_[1][0] holds the
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+ # slot. But a padding member may have been inserted here, which
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+ # breaks the assumption and leads to chaos.
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+ # TODO: this is a quick fix. Fixing/working around in the BCC
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+ # internal library is the right thing to do.
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+ if f2 == '__pad_1' and len(self.Key._fields_) == 3:
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+ f2 = self.Key._fields_[2][0]
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+
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for k, v in self.items():
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bucket = getattr(k, f1)
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if bucket_fn:
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--
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2.20.1
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