mirror of
https://github.com/torvalds/linux.git
synced 2026-04-18 14:53:58 -04:00
63c49efc98
Replace bpf_strlcpy() in bpf_util.h with a sized_strscpy(), which is a simplified sized_strscpy() from the kernel (lib/string.c [1]). It: * takes a count (destination size) parameter * guarantees NULL-termination * returns the number of characters copied or -E2BIG Re-define strscpy macro similar to in-kernel implementation [2]: allow the count parameter to be optional. Add #ifdef-s to tools/include/linux/args.h, as they may be defined in other system headers (for example, __CONCAT in sys/cdefs.h). Fixup the single existing bpf_strlcpy() call in cgroup_helpers.c [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/lib/string.c?h=v6.19#n113 [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/string.h?h=v6.19#n91 Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev> Link: https://lore.kernel.org/r/20260223190736.649171-2-ihor.solodrai@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
97 lines
2.2 KiB
C
97 lines
2.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __BPF_UTIL__
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#define __BPF_UTIL__
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <errno.h>
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#include <syscall.h>
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#include <bpf/libbpf.h> /* libbpf_num_possible_cpus */
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#include <linux/args.h>
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static inline unsigned int bpf_num_possible_cpus(void)
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{
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int possible_cpus = libbpf_num_possible_cpus();
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if (possible_cpus < 0) {
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printf("Failed to get # of possible cpus: '%s'!\n",
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strerror(-possible_cpus));
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exit(1);
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}
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return possible_cpus;
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}
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/*
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* Simplified strscpy() implementation. The kernel one is in lib/string.c
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*/
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static inline ssize_t sized_strscpy(char *dest, const char *src, size_t count)
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{
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long res = 0;
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if (count == 0)
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return -E2BIG;
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while (count > 1) {
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char c;
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c = src[res];
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dest[res] = c;
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if (!c)
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return res;
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res++;
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count--;
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}
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/* Force NUL-termination. */
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dest[res] = '\0';
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/* Return E2BIG if the source didn't stop */
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return src[res] ? -E2BIG : res;
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}
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#define __strscpy0(dst, src, ...) \
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sized_strscpy(dst, src, sizeof(dst))
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#define __strscpy1(dst, src, size) \
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sized_strscpy(dst, src, size)
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#undef strscpy /* Redefine the placeholder from tools/include/linux/string.h */
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#define strscpy(dst, src, ...) \
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CONCATENATE(__strscpy, COUNT_ARGS(__VA_ARGS__))(dst, src, __VA_ARGS__)
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#define __bpf_percpu_val_align __attribute__((__aligned__(8)))
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#define BPF_DECLARE_PERCPU(type, name) \
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struct { type v; /* padding */ } __bpf_percpu_val_align \
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name[bpf_num_possible_cpus()]
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#define bpf_percpu(name, cpu) name[(cpu)].v
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#ifndef ARRAY_SIZE
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# define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
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#endif
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#ifndef sizeof_field
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#define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER))
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#endif
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#ifndef offsetofend
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#define offsetofend(TYPE, MEMBER) \
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(offsetof(TYPE, MEMBER) + sizeof_field(TYPE, MEMBER))
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#endif
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/* Availability of gettid across glibc versions is hit-and-miss, therefore
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* fallback to syscall in this macro and use it everywhere.
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*/
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#ifndef sys_gettid
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#define sys_gettid() syscall(SYS_gettid)
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#endif
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/* and poison usage to ensure it does not creep back in. */
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#pragma GCC poison gettid
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#ifndef ENOTSUPP
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#define ENOTSUPP 524
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#endif
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#endif /* __BPF_UTIL__ */
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