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authorLinus Torvalds <torvalds@linux-foundation.org>2024-09-21 09:27:50 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2024-09-21 09:27:50 -0700
commit440b65232829fad69947b8de983c13a525cc8871 (patch)
tree3cab57fca48b43ba0e11804683b33b71743494c6 /samples
parent1ec6d097897a35dfb55c4c31fc8633cf5be46497 (diff)
parent5277d130947ba8c0d54c16eed89eb97f0b6d2e5a (diff)
downloadlwn-440b65232829fad69947b8de983c13a525cc8871.tar.gz
lwn-440b65232829fad69947b8de983c13a525cc8871.zip
Merge tag 'bpf-next-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov: - Introduce '__attribute__((bpf_fastcall))' for helpers and kfuncs with corresponding support in LLVM. It is similar to existing 'no_caller_saved_registers' attribute in GCC/LLVM with a provision for backward compatibility. It allows compilers generate more efficient BPF code assuming the verifier or JITs will inline or partially inline a helper/kfunc with such attribute. bpf_cast_to_kern_ctx, bpf_rdonly_cast, bpf_get_smp_processor_id are the first set of such helpers. - Harden and extend ELF build ID parsing logic. When called from sleepable context the relevants parts of ELF file will be read to find and fetch .note.gnu.build-id information. Also harden the logic to avoid TOCTOU, overflow, out-of-bounds problems. - Improvements and fixes for sched-ext: - Allow passing BPF iterators as kfunc arguments - Make the pointer returned from iter_next method trusted - Fix x86 JIT convergence issue due to growing/shrinking conditional jumps in variable length encoding - BPF_LSM related: - Introduce few VFS kfuncs and consolidate them in fs/bpf_fs_kfuncs.c - Enforce correct range of return values from certain LSM hooks - Disallow attaching to other LSM hooks - Prerequisite work for upcoming Qdisc in BPF: - Allow kptrs in program provided structs - Support for gen_epilogue in verifier_ops - Important fixes: - Fix uprobe multi pid filter check - Fix bpf_strtol and bpf_strtoul helpers - Track equal scalars history on per-instruction level - Fix tailcall hierarchy on x86 and arm64 - Fix signed division overflow to prevent INT_MIN/-1 trap on x86 - Fix get kernel stack in BPF progs attached to tracepoint:syscall - Selftests: - Add uprobe bench/stress tool - Generate file dependencies to drastically improve re-build time - Match JIT-ed and BPF asm with __xlated/__jited keywords - Convert older tests to test_progs framework - Add support for RISC-V - Few fixes when BPF programs are compiled with GCC-BPF backend (support for GCC-BPF in BPF CI is ongoing in parallel) - Add traffic monitor - Enable cross compile and musl libc * tag 'bpf-next-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (260 commits) btf: require pahole 1.21+ for DEBUG_INFO_BTF with default DWARF version btf: move pahole check in scripts/link-vmlinux.sh to lib/Kconfig.debug btf: remove redundant CONFIG_BPF test in scripts/link-vmlinux.sh bpf: Call the missed kfree() when there is no special field in btf bpf: Call the missed btf_record_free() when map creation fails selftests/bpf: Add a test case to write mtu result into .rodata selftests/bpf: Add a test case to write strtol result into .rodata selftests/bpf: Rename ARG_PTR_TO_LONG test description selftests/bpf: Fix ARG_PTR_TO_LONG {half-,}uninitialized test bpf: Zero former ARG_PTR_TO_{LONG,INT} args in case of error bpf: Improve check_raw_mode_ok test for MEM_UNINIT-tagged types bpf: Fix helper writes to read-only maps bpf: Remove truncation test in bpf_strtol and bpf_strtoul helpers bpf: Fix bpf_strtol and bpf_strtoul helpers for 32bit selftests/bpf: Add tests for sdiv/smod overflow cases bpf: Fix a sdiv overflow issue libbpf: Add bpf_object__token_fd accessor docs/bpf: Add missing BPF program types to docs docs/bpf: Add constant values for linkages bpf: Use fake pt_regs when doing bpf syscall tracepoint tracing ...
Diffstat (limited to 'samples')
-rw-r--r--samples/bpf/Makefile9
-rw-r--r--samples/bpf/tracex2.bpf.c99
-rw-r--r--samples/bpf/tracex2_user.c187
-rw-r--r--samples/bpf/tracex4.bpf.c4
4 files changed, 7 insertions, 292 deletions
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 3e003dd6bea0..7afe040cf43b 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -13,7 +13,6 @@ tprogs-y += sockex1
tprogs-y += sockex2
tprogs-y += sockex3
tprogs-y += tracex1
-tprogs-y += tracex2
tprogs-y += tracex3
tprogs-y += tracex4
tprogs-y += tracex5
@@ -63,7 +62,6 @@ sockex1-objs := sockex1_user.o
sockex2-objs := sockex2_user.o
sockex3-objs := sockex3_user.o
tracex1-objs := tracex1_user.o $(TRACE_HELPERS)
-tracex2-objs := tracex2_user.o
tracex3-objs := tracex3_user.o
tracex4-objs := tracex4_user.o
tracex5-objs := tracex5_user.o $(TRACE_HELPERS)
@@ -105,7 +103,6 @@ always-y += sockex1_kern.o
always-y += sockex2_kern.o
always-y += sockex3_kern.o
always-y += tracex1.bpf.o
-always-y += tracex2.bpf.o
always-y += tracex3.bpf.o
always-y += tracex4.bpf.o
always-y += tracex5.bpf.o
@@ -169,6 +166,10 @@ BPF_EXTRA_CFLAGS += -I$(srctree)/arch/mips/include/asm/mach-generic
endif
endif
+ifeq ($(ARCH), x86)
+BPF_EXTRA_CFLAGS += -fcf-protection
+endif
+
TPROGS_CFLAGS += -Wall -O2
TPROGS_CFLAGS += -Wmissing-prototypes
TPROGS_CFLAGS += -Wstrict-prototypes
@@ -405,7 +406,7 @@ $(obj)/%.o: $(src)/%.c
-Wno-gnu-variable-sized-type-not-at-end \
-Wno-address-of-packed-member -Wno-tautological-compare \
-Wno-unknown-warning-option $(CLANG_ARCH_ARGS) \
- -fno-asynchronous-unwind-tables -fcf-protection \
+ -fno-asynchronous-unwind-tables \
-I$(srctree)/samples/bpf/ -include asm_goto_workaround.h \
-O2 -emit-llvm -Xclang -disable-llvm-passes -c $< -o - | \
$(OPT) -O2 -mtriple=bpf-pc-linux | $(LLVM_DIS) | \
diff --git a/samples/bpf/tracex2.bpf.c b/samples/bpf/tracex2.bpf.c
deleted file mode 100644
index 0a5c75b367be..000000000000
--- a/samples/bpf/tracex2.bpf.c
+++ /dev/null
@@ -1,99 +0,0 @@
-/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of version 2 of the GNU General Public
- * License as published by the Free Software Foundation.
- */
-#include "vmlinux.h"
-#include <linux/version.h>
-#include <bpf/bpf_helpers.h>
-#include <bpf/bpf_tracing.h>
-#include <bpf/bpf_core_read.h>
-
-struct {
- __uint(type, BPF_MAP_TYPE_HASH);
- __type(key, long);
- __type(value, long);
- __uint(max_entries, 1024);
-} my_map SEC(".maps");
-
-/* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe
- * example will no longer be meaningful
- */
-SEC("kprobe/kfree_skb_reason")
-int bpf_prog2(struct pt_regs *ctx)
-{
- long loc = 0;
- long init_val = 1;
- long *value;
-
- /* read ip of kfree_skb_reason caller.
- * non-portable version of __builtin_return_address(0)
- */
- BPF_KPROBE_READ_RET_IP(loc, ctx);
-
- value = bpf_map_lookup_elem(&my_map, &loc);
- if (value)
- *value += 1;
- else
- bpf_map_update_elem(&my_map, &loc, &init_val, BPF_ANY);
- return 0;
-}
-
-static unsigned int log2(unsigned int v)
-{
- unsigned int r;
- unsigned int shift;
-
- r = (v > 0xFFFF) << 4; v >>= r;
- shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
- shift = (v > 0xF) << 2; v >>= shift; r |= shift;
- shift = (v > 0x3) << 1; v >>= shift; r |= shift;
- r |= (v >> 1);
- return r;
-}
-
-static unsigned int log2l(unsigned long v)
-{
- unsigned int hi = v >> 32;
- if (hi)
- return log2(hi) + 32;
- else
- return log2(v);
-}
-
-struct hist_key {
- char comm[16];
- u64 pid_tgid;
- u64 uid_gid;
- u64 index;
-};
-
-struct {
- __uint(type, BPF_MAP_TYPE_PERCPU_HASH);
- __uint(key_size, sizeof(struct hist_key));
- __uint(value_size, sizeof(long));
- __uint(max_entries, 1024);
-} my_hist_map SEC(".maps");
-
-SEC("ksyscall/write")
-int BPF_KSYSCALL(bpf_prog3, unsigned int fd, const char *buf, size_t count)
-{
- long init_val = 1;
- long *value;
- struct hist_key key;
-
- key.index = log2l(count);
- key.pid_tgid = bpf_get_current_pid_tgid();
- key.uid_gid = bpf_get_current_uid_gid();
- bpf_get_current_comm(&key.comm, sizeof(key.comm));
-
- value = bpf_map_lookup_elem(&my_hist_map, &key);
- if (value)
- __sync_fetch_and_add(value, 1);
- else
- bpf_map_update_elem(&my_hist_map, &key, &init_val, BPF_ANY);
- return 0;
-}
-char _license[] SEC("license") = "GPL";
-u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/tracex2_user.c b/samples/bpf/tracex2_user.c
deleted file mode 100644
index 2131f1648cf1..000000000000
--- a/samples/bpf/tracex2_user.c
+++ /dev/null
@@ -1,187 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-#include <stdio.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <signal.h>
-#include <string.h>
-
-#include <bpf/bpf.h>
-#include <bpf/libbpf.h>
-#include "bpf_util.h"
-
-#define MAX_INDEX 64
-#define MAX_STARS 38
-
-/* my_map, my_hist_map */
-static int map_fd[2];
-
-static void stars(char *str, long val, long max, int width)
-{
- int i;
-
- for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++)
- str[i] = '*';
- if (val > max)
- str[i - 1] = '+';
- str[i] = '\0';
-}
-
-struct task {
- char comm[16];
- __u64 pid_tgid;
- __u64 uid_gid;
-};
-
-struct hist_key {
- struct task t;
- __u32 index;
-};
-
-#define SIZE sizeof(struct task)
-
-static void print_hist_for_pid(int fd, void *task)
-{
- unsigned int nr_cpus = bpf_num_possible_cpus();
- struct hist_key key = {}, next_key;
- long values[nr_cpus];
- char starstr[MAX_STARS];
- long value;
- long data[MAX_INDEX] = {};
- int max_ind = -1;
- long max_value = 0;
- int i, ind;
-
- while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
- if (memcmp(&next_key, task, SIZE)) {
- key = next_key;
- continue;
- }
- bpf_map_lookup_elem(fd, &next_key, values);
- value = 0;
- for (i = 0; i < nr_cpus; i++)
- value += values[i];
- ind = next_key.index;
- data[ind] = value;
- if (value && ind > max_ind)
- max_ind = ind;
- if (value > max_value)
- max_value = value;
- key = next_key;
- }
-
- printf(" syscall write() stats\n");
- printf(" byte_size : count distribution\n");
- for (i = 1; i <= max_ind + 1; i++) {
- stars(starstr, data[i - 1], max_value, MAX_STARS);
- printf("%8ld -> %-8ld : %-8ld |%-*s|\n",
- (1l << i) >> 1, (1l << i) - 1, data[i - 1],
- MAX_STARS, starstr);
- }
-}
-
-static void print_hist(int fd)
-{
- struct hist_key key = {}, next_key;
- static struct task tasks[1024];
- int task_cnt = 0;
- int i;
-
- while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
- int found = 0;
-
- for (i = 0; i < task_cnt; i++)
- if (memcmp(&tasks[i], &next_key, SIZE) == 0)
- found = 1;
- if (!found)
- memcpy(&tasks[task_cnt++], &next_key, SIZE);
- key = next_key;
- }
-
- for (i = 0; i < task_cnt; i++) {
- printf("\npid %d cmd %s uid %d\n",
- (__u32) tasks[i].pid_tgid,
- tasks[i].comm,
- (__u32) tasks[i].uid_gid);
- print_hist_for_pid(fd, &tasks[i]);
- }
-
-}
-
-static void int_exit(int sig)
-{
- print_hist(map_fd[1]);
- exit(0);
-}
-
-int main(int ac, char **argv)
-{
- long key, next_key, value;
- struct bpf_link *links[2];
- struct bpf_program *prog;
- struct bpf_object *obj;
- char filename[256];
- int i, j = 0;
- FILE *f;
-
- snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
- obj = bpf_object__open_file(filename, NULL);
- if (libbpf_get_error(obj)) {
- fprintf(stderr, "ERROR: opening BPF object file failed\n");
- return 0;
- }
-
- /* load BPF program */
- if (bpf_object__load(obj)) {
- fprintf(stderr, "ERROR: loading BPF object file failed\n");
- goto cleanup;
- }
-
- map_fd[0] = bpf_object__find_map_fd_by_name(obj, "my_map");
- map_fd[1] = bpf_object__find_map_fd_by_name(obj, "my_hist_map");
- if (map_fd[0] < 0 || map_fd[1] < 0) {
- fprintf(stderr, "ERROR: finding a map in obj file failed\n");
- goto cleanup;
- }
-
- signal(SIGINT, int_exit);
- signal(SIGTERM, int_exit);
-
- /* start 'ping' in the background to have some kfree_skb_reason
- * events */
- f = popen("ping -4 -c5 localhost", "r");
- (void) f;
-
- /* start 'dd' in the background to have plenty of 'write' syscalls */
- f = popen("dd if=/dev/zero of=/dev/null count=5000000", "r");
- (void) f;
-
- bpf_object__for_each_program(prog, obj) {
- links[j] = bpf_program__attach(prog);
- if (libbpf_get_error(links[j])) {
- fprintf(stderr, "ERROR: bpf_program__attach failed\n");
- links[j] = NULL;
- goto cleanup;
- }
- j++;
- }
-
- for (i = 0; i < 5; i++) {
- key = 0;
- while (bpf_map_get_next_key(map_fd[0], &key, &next_key) == 0) {
- bpf_map_lookup_elem(map_fd[0], &next_key, &value);
- printf("location 0x%lx count %ld\n", next_key, value);
- key = next_key;
- }
- if (key)
- printf("\n");
- sleep(1);
- }
- print_hist(map_fd[1]);
-
-cleanup:
- for (j--; j >= 0; j--)
- bpf_link__destroy(links[j]);
-
- bpf_object__close(obj);
- return 0;
-}
diff --git a/samples/bpf/tracex4.bpf.c b/samples/bpf/tracex4.bpf.c
index ca826750901a..d786492fd926 100644
--- a/samples/bpf/tracex4.bpf.c
+++ b/samples/bpf/tracex4.bpf.c
@@ -33,13 +33,13 @@ int bpf_prog1(struct pt_regs *ctx)
return 0;
}
-SEC("kretprobe/kmem_cache_alloc_node")
+SEC("kretprobe/kmem_cache_alloc_node_noprof")
int bpf_prog2(struct pt_regs *ctx)
{
long ptr = PT_REGS_RC(ctx);
long ip = 0;
- /* get ip address of kmem_cache_alloc_node() caller */
+ /* get ip address of kmem_cache_alloc_node_noprof() caller */
BPF_KRETPROBE_READ_RET_IP(ip, ctx);
struct pair v = {