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authorLinus Torvalds <[email protected]>2025-07-30 16:58:50 +0000
committerLinus Torvalds <[email protected]>2025-07-30 16:58:50 +0000
commitd9104cec3e8fe4b458b74709853231385779001f (patch)
tree1ffc3baa0e963d3301765a5d6cbd5410c8796ee4 /tools/testing/selftests/bpf/progs/verifier_map_in_map.c
parentMerge tag 'net-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ne... (diff)
parentMerge branch 'bpf-show-precise-rejected-function-when-attaching-to-__noreturn... (diff)
downloadkernel-d9104cec3e8fe4b458b74709853231385779001f.tar.gz
kernel-d9104cec3e8fe4b458b74709853231385779001f.zip
Merge tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov: - Remove usermode driver (UMD) framework (Thomas Weißschuh) - Introduce Strongly Connected Component (SCC) in the verifier to detect loops and refine register liveness (Eduard Zingerman) - Allow 'void *' cast using bpf_rdonly_cast() and corresponding '__arg_untrusted' for global function parameters (Eduard Zingerman) - Improve precision for BPF_ADD and BPF_SUB operations in the verifier (Harishankar Vishwanathan) - Teach the verifier that constant pointer to a map cannot be NULL (Ihor Solodrai) - Introduce BPF streams for error reporting of various conditions detected by BPF runtime (Kumar Kartikeya Dwivedi) - Teach the verifier to insert runtime speculation barrier (lfence on x86) to mitigate speculative execution instead of rejecting the programs (Luis Gerhorst) - Various improvements for 'veristat' (Mykyta Yatsenko) - For CONFIG_DEBUG_KERNEL config warn on internal verifier errors to improve bug detection by syzbot (Paul Chaignon) - Support BPF private stack on arm64 (Puranjay Mohan) - Introduce bpf_cgroup_read_xattr() kfunc to read xattr of cgroup's node (Song Liu) - Introduce kfuncs for read-only string opreations (Viktor Malik) - Implement show_fdinfo() for bpf_links (Tao Chen) - Reduce verifier's stack consumption (Yonghong Song) - Implement mprog API for cgroup-bpf programs (Yonghong Song) * tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (192 commits) selftests/bpf: Migrate fexit_noreturns case into tracing_failure test suite selftests/bpf: Add selftest for attaching tracing programs to functions in deny list bpf: Add log for attaching tracing programs to functions in deny list bpf: Show precise rejected function when attaching fexit/fmod_ret to __noreturn functions bpf: Fix various typos in verifier.c comments bpf: Add third round of bounds deduction selftests/bpf: Test invariants on JSLT crossing sign selftests/bpf: Test cross-sign 64bits range refinement selftests/bpf: Update reg_bound range refinement logic bpf: Improve bounds when s64 crosses sign boundary bpf: Simplify bounds refinement from s32 selftests/bpf: Enable private stack tests for arm64 bpf, arm64: JIT support for private stack bpf: Move bpf_jit_get_prog_name() to core.c bpf, arm64: Fix fp initialization for exception boundary umd: Remove usermode driver framework bpf/preload: Don't select USERMODE_DRIVER selftests/bpf: Fix test dynptr/test_dynptr_memset_xdp_chunks failure selftests/bpf: Fix test dynptr/test_dynptr_copy_xdp failure selftests/bpf: Increase xdp data size for arm64 64K page size ...
Diffstat (limited to 'tools/testing/selftests/bpf/progs/verifier_map_in_map.c')
-rw-r--r--tools/testing/selftests/bpf/progs/verifier_map_in_map.c118
1 files changed, 118 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/verifier_map_in_map.c b/tools/testing/selftests/bpf/progs/verifier_map_in_map.c
index 7d088ba99ea5..16b761e510f0 100644
--- a/tools/testing/selftests/bpf/progs/verifier_map_in_map.c
+++ b/tools/testing/selftests/bpf/progs/verifier_map_in_map.c
@@ -139,4 +139,122 @@ __naked void on_the_inner_map_pointer(void)
: __clobber_all);
}
+SEC("socket")
+__description("map_ptr is never null")
+__success
+__naked void map_ptr_is_never_null(void)
+{
+ asm volatile (" \
+ r0 = 0; \
+ r1 = %[map_in_map] ll; \
+ if r1 != 0 goto l0_%=; \
+ r10 = 42; \
+l0_%=: exit; \
+" :
+ : __imm(bpf_map_lookup_elem),
+ __imm_addr(map_in_map)
+ : __clobber_all);
+}
+
+SEC("socket")
+__description("map_ptr is never null inner")
+__success
+__naked void map_ptr_is_never_null_inner(void)
+{
+ asm volatile (" \
+ r1 = 0; \
+ *(u32*)(r10 - 4) = r1; \
+ r2 = r10; \
+ r2 += -4; \
+ r1 = %[map_in_map] ll; \
+ call %[bpf_map_lookup_elem]; \
+ if r0 == 0 goto l0_%=; \
+ if r0 != 0 goto l0_%=; \
+ r10 = 42; \
+l0_%=: exit; \
+" :
+ : __imm(bpf_map_lookup_elem),
+ __imm_addr(map_in_map)
+ : __clobber_all);
+}
+
+SEC("socket")
+__description("map_ptr is never null inner spill fill")
+__success
+__naked void map_ptr_is_never_null_inner_spill_fill(void)
+{
+ asm volatile (" \
+ r1 = 0; \
+ *(u32*)(r10 - 4) = r1; \
+ r2 = r10; \
+ r2 += -4; \
+ r1 = %[map_in_map] ll; \
+ call %[bpf_map_lookup_elem]; \
+ if r0 != 0 goto l0_%=; \
+ exit; \
+l0_%=: *(u64 *)(r10 -16) = r0; \
+ r1 = *(u64 *)(r10 -16); \
+ if r1 == 0 goto l1_%=; \
+ exit; \
+l1_%=: r10 = 42; \
+ exit; \
+" :
+ : __imm(bpf_map_lookup_elem),
+ __imm_addr(map_in_map)
+ : __clobber_all);
+}
+
+struct {
+ __uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
+ __uint(max_entries, 1);
+ __type(key, int);
+ __type(value, int);
+ __array(values, struct {
+ __uint(type, BPF_MAP_TYPE_RINGBUF);
+ __uint(max_entries, 64 * 1024);
+ });
+} rb_in_map SEC(".maps");
+
+struct rb_ctx {
+ void *rb;
+ struct bpf_dynptr dptr;
+};
+
+static __always_inline struct rb_ctx __rb_event_reserve(__u32 sz)
+{
+ struct rb_ctx rb_ctx = {};
+ void *rb;
+ __u32 cpu = bpf_get_smp_processor_id();
+ __u32 rb_slot = cpu & 1;
+
+ rb = bpf_map_lookup_elem(&rb_in_map, &rb_slot);
+ if (!rb)
+ return rb_ctx;
+
+ rb_ctx.rb = rb;
+ bpf_ringbuf_reserve_dynptr(rb, sz, 0, &rb_ctx.dptr);
+
+ return rb_ctx;
+}
+
+static __noinline void __rb_event_submit(struct rb_ctx *ctx)
+{
+ if (!ctx->rb)
+ return;
+
+ /* If the verifier (incorrectly) concludes that ctx->rb can be
+ * NULL at this point, we'll get "BPF_EXIT instruction in main
+ * prog would lead to reference leak" error
+ */
+ bpf_ringbuf_submit_dynptr(&ctx->dptr, 0);
+}
+
+SEC("socket")
+int map_ptr_is_never_null_rb(void *ctx)
+{
+ struct rb_ctx event_ctx = __rb_event_reserve(256);
+ __rb_event_submit(&event_ctx);
+ return 0;
+}
+
char _license[] SEC("license") = "GPL";