78 lines
2.3 KiB
Diff
78 lines
2.3 KiB
Diff
From a5d75daa8c467a863ecf297982b70ed284adc0e9 Mon Sep 17 00:00:00 2001
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From: Douglas Raillard <douglas.raillard@arm.com>
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Date: Tue, 24 May 2022 10:44:47 +0100
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Subject: [PATCH] libbpf: Fix determine_ptr_size() guessing
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One strategy employed by libbpf to guess the pointer size is by finding
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the size of "unsigned long" type. This is achieved by looking for a type
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of with the expected name and checking its size.
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Unfortunately, the C syntax is friendlier to humans than to computers
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as there is some variety in how such a type can be named. Specifically,
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gcc and clang do not use the same names for integer types in debug info:
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- clang uses "unsigned long"
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- gcc uses "long unsigned int"
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Lookup all the names for such a type so that libbpf can hope to find the
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information it wants.
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Signed-off-by: Douglas Raillard <douglas.raillard@arm.com>
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Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
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Acked-by: Yonghong Song <yhs@fb.com>
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Link: https://lore.kernel.org/bpf/20220524094447.332186-1-douglas.raillard@arm.com
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---
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src/btf.c | 26 ++++++++++++++++++++------
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1 file changed, 20 insertions(+), 6 deletions(-)
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diff --git a/src/btf.c b/src/btf.c
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index bb1e06eb1..3d6c30d9a 100644
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--- a/src/btf.c
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+++ b/src/btf.c
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@@ -472,9 +472,22 @@ const struct btf_type *btf__type_by_id(const struct btf *btf, __u32 type_id)
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static int determine_ptr_size(const struct btf *btf)
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{
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+ static const char * const long_aliases[] = {
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+ "long",
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+ "long int",
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+ "int long",
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+ "unsigned long",
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+ "long unsigned",
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+ "unsigned long int",
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+ "unsigned int long",
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+ "long unsigned int",
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+ "long int unsigned",
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+ "int unsigned long",
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+ "int long unsigned",
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+ };
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const struct btf_type *t;
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const char *name;
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- int i, n;
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+ int i, j, n;
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if (btf->base_btf && btf->base_btf->ptr_sz > 0)
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return btf->base_btf->ptr_sz;
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@@ -485,15 +498,16 @@ static int determine_ptr_size(const struct btf *btf)
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if (!btf_is_int(t))
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continue;
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+ if (t->size != 4 && t->size != 8)
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+ continue;
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+
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name = btf__name_by_offset(btf, t->name_off);
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if (!name)
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continue;
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- if (strcmp(name, "long int") == 0 ||
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- strcmp(name, "long unsigned int") == 0) {
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- if (t->size != 4 && t->size != 8)
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- continue;
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- return t->size;
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+ for (j = 0; j < ARRAY_SIZE(long_aliases); j++) {
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+ if (strcmp(name, long_aliases[j]) == 0)
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+ return t->size;
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}
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}
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