Commit 1520e846 authored by Khem Raj's avatar Khem Raj Committed by Andrii Nakryiko
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libbpf: Fix build warning on ref_ctr_off for 32-bit architectures 



Clang warns on 32-bit ARM on this comparision:

libbpf.c:10497:18: error: result of comparison of constant 4294967296 with expression of type 'size_t' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare]
        if (ref_ctr_off >= (1ULL << PERF_UPROBE_REF_CTR_OFFSET_BITS))
            ~~~~~~~~~~~ ^  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Typecast ref_ctr_off to __u64 in the check conditional, it is false on
32bit anyways.

Signed-off-by: default avatarKhem Raj <raj.khem@gmail.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221219191526.296264-1-raj.khem@gmail.com
parent cafb92d7

tools/lib/bpf/libbpf.c

+1 −1
Original line number Diff line number Diff line
@@ -9903,7 +9903,7 @@ static int perf_event_open_probe(bool uprobe, bool retprobe, const char *name, 
	char errmsg[STRERR_BUFSIZE];

	int type, pfd;



	if (ref_ctr_off >= (1ULL << PERF_UPROBE_REF_CTR_OFFSET_BITS))

	if ((__u64)ref_ctr_off >= (1ULL << PERF_UPROBE_REF_CTR_OFFSET_BITS))

		return -EINVAL;



	memset(&attr, 0, attr_sz);