61 lines
2.1 KiB
Diff
61 lines
2.1 KiB
Diff
From 9196accd36718701e49be67194b78de6af7fe699 Mon Sep 17 00:00:00 2001
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From: Jakub Bogusz <qboosh@pld-linux.org>
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Date: Thu, 9 Jul 2020 15:57:23 -0700
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Subject: [PATCH 042/201] libbpf: Fix libbpf hashmap on (I)LP32 architectures
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mainline inclusion
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from mainline-v5.8-rc5
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commit b2f9f1535bb93ee5fa2ea30ac1c26fa0d676154c
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category: bugfix
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bugzilla: https://gitee.com/openeuler/kernel/issues/I8C0CX
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Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b2f9f1535bb93ee5fa2ea30ac1c26fa0d676154c
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------------------------------------------------------------------------
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On ILP32, 64-bit result was shifted by value calculated for 32-bit long type
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and returned value was much outside hashmap capacity.
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As advised by Andrii Nakryiko, this patch uses different hashing variant for
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architectures with size_t shorter than long long.
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Fixes: e3b924224028 ("libbpf: add resizable non-thread safe internal hashmap")
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Signed-off-by: Jakub Bogusz <qboosh@pld-linux.org>
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Signed-off-by: Andrii Nakryiko <andriin@fb.com>
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Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Link: https://lore.kernel.org/bpf/20200709225723.1069937-1-andriin@fb.com
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Signed-off-by: hongrongxuan <hongrongxuan@huawei.com>
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---
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tools/lib/bpf/hashmap.h | 12 ++++++++----
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1 file changed, 8 insertions(+), 4 deletions(-)
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diff --git a/tools/lib/bpf/hashmap.h b/tools/lib/bpf/hashmap.h
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index df59fd4fc95b..e0af36b0e5d8 100644
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--- a/tools/lib/bpf/hashmap.h
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+++ b/tools/lib/bpf/hashmap.h
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@@ -11,14 +11,18 @@
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#include <stdbool.h>
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#include <stddef.h>
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#include <limits.h>
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-#ifndef __WORDSIZE
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-#define __WORDSIZE (__SIZEOF_LONG__ * 8)
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-#endif
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static inline size_t hash_bits(size_t h, int bits)
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{
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/* shuffle bits and return requested number of upper bits */
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- return (h * 11400714819323198485llu) >> (__WORDSIZE - bits);
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+#if (__SIZEOF_SIZE_T__ == __SIZEOF_LONG_LONG__)
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+ /* LP64 case */
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+ return (h * 11400714819323198485llu) >> (__SIZEOF_LONG_LONG__ * 8 - bits);
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+#elif (__SIZEOF_SIZE_T__ <= __SIZEOF_LONG__)
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+ return (h * 2654435769lu) >> (__SIZEOF_LONG__ * 8 - bits);
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+#else
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+# error "Unsupported size_t size"
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+#endif
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}
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typedef size_t (*hashmap_hash_fn)(const void *key, void *ctx);
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--
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2.27.0
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