From 456d53554ca7e93d7e5e8eb7fe8c906d5ec6e7d0 Mon Sep 17 00:00:00 2001 From: "Daniel T. Lee" Date: Fri, 18 Aug 2023 18:01:19 +0900 Subject: samples/bpf: simplify spintest with kprobe.multi With the introduction of kprobe.multi, it is now possible to attach multiple kprobes to a single BPF program without the need for multiple definitions. Additionally, this method supports wildcard-based matching, allowing for further simplification of BPF programs. In here, an asterisk (*) wildcard is used to map to all symbols relevant to spin_{lock|unlock}. Furthermore, since kprobe.multi handles symbol matching, this commit eliminates the need for the previous logic of reading the ksym table to verify the existence of symbols. Signed-off-by: Daniel T. Lee Link: https://lore.kernel.org/r/20230818090119.477441-10-danieltimlee@gmail.com Signed-off-by: Alexei Starovoitov --- samples/bpf/spintest.bpf.c | 17 +++-------------- samples/bpf/spintest_user.c | 22 +++++++--------------- 2 files changed, 10 insertions(+), 29 deletions(-) (limited to 'samples') diff --git a/samples/bpf/spintest.bpf.c b/samples/bpf/spintest.bpf.c index 15740b16a3f7..cba5a9d50783 100644 --- a/samples/bpf/spintest.bpf.c +++ b/samples/bpf/spintest.bpf.c @@ -47,20 +47,9 @@ int foo(struct pt_regs *ctx) \ } /* add kprobes to all possible *spin* functions */ -SEC("kprobe/spin_unlock")PROG(p1) -SEC("kprobe/spin_lock")PROG(p2) -SEC("kprobe/mutex_spin_on_owner")PROG(p3) -SEC("kprobe/rwsem_spin_on_owner")PROG(p4) -SEC("kprobe/spin_unlock_irqrestore")PROG(p5) -SEC("kprobe/_raw_spin_unlock_irqrestore")PROG(p6) -SEC("kprobe/_raw_spin_unlock_bh")PROG(p7) -SEC("kprobe/_raw_spin_unlock")PROG(p8) -SEC("kprobe/_raw_spin_lock_irqsave")PROG(p9) -SEC("kprobe/_raw_spin_trylock_bh")PROG(p10) -SEC("kprobe/_raw_spin_lock_irq")PROG(p11) -SEC("kprobe/_raw_spin_trylock")PROG(p12) -SEC("kprobe/_raw_spin_lock")PROG(p13) -SEC("kprobe/_raw_spin_lock_bh")PROG(p14) +SEC("kprobe.multi/spin_*lock*")PROG(spin_lock) +SEC("kprobe.multi/*_spin_on_owner")PROG(spin_on_owner) +SEC("kprobe.multi/_raw_spin_*lock*")PROG(raw_spin_lock) /* and to inner bpf helpers */ SEC("kprobe/htab_map_update_elem")PROG(p15) diff --git a/samples/bpf/spintest_user.c b/samples/bpf/spintest_user.c index 8c77600776fb..55971edb1088 100644 --- a/samples/bpf/spintest_user.c +++ b/samples/bpf/spintest_user.c @@ -9,13 +9,12 @@ int main(int ac, char **argv) { - char filename[256], symbol[256]; struct bpf_object *obj = NULL; struct bpf_link *links[20]; long key, next_key, value; struct bpf_program *prog; int map_fd, i, j = 0; - const char *section; + char filename[256]; struct ksym *sym; if (load_kallsyms()) { @@ -44,20 +43,13 @@ int main(int ac, char **argv) } bpf_object__for_each_program(prog, obj) { - section = bpf_program__section_name(prog); - if (sscanf(section, "kprobe/%s", symbol) != 1) - continue; - - /* Attach prog only when symbol exists */ - if (ksym_get_addr(symbol)) { - links[j] = bpf_program__attach(prog); - if (libbpf_get_error(links[j])) { - fprintf(stderr, "bpf_program__attach failed\n"); - links[j] = NULL; - goto cleanup; - } - j++; + links[j] = bpf_program__attach(prog); + if (libbpf_get_error(links[j])) { + fprintf(stderr, "bpf_program__attach failed\n"); + links[j] = NULL; + goto cleanup; } + j++; } for (i = 0; i < 5; i++) { -- cgit v1.2.3-58-ga151