Introduce bpf_arch_text_invalidate and use it to fill unused part of the bpf_prog_pack with illegal instructions when a BPF program is freed.
Showing the changes to kernel (1 of 3 files). Show all
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| @@ -968,6 +968,9 @@ static void bpf_prog_pack_free(struct bpf_binary_header *hdr) · 967 unmodified lines | |||
| 968 | nbits = BPF_PROG_SIZE_TO_NBITS(hdr->size); | 968 | nbits = BPF_PROG_SIZE_TO_NBITS(hdr->size); |
| 969 | pos = ((unsigned long)hdr - (unsigned long)pack_ptr) >> BPF_PROG_CHUNK_SHIFT; | 969 | pos = ((unsigned long)hdr - (unsigned long)pack_ptr) >> BPF_PROG_CHUNK_SHIFT; |
| 970 | 970 | ||
| 971 | WARN_ONCE(bpf_arch_text_invalidate(hdr, hdr->size), | ||
| 972 | "bpf_prog_pack bug: missing bpf_arch_text_invalidate?\n"); | ||
| 973 | |||
| 971 | bitmap_clear(pack->bitmap, pos, nbits); | 974 | bitmap_clear(pack->bitmap, pos, nbits); |
| 972 | if (bitmap_find_next_zero_area(pack->bitmap, bpf_prog_chunk_count(), 0, | 975 | if (bitmap_find_next_zero_area(pack->bitmap, bpf_prog_chunk_count(), 0, |
| 973 | bpf_prog_chunk_count(), 0) == 0) { | 976 | bpf_prog_chunk_count(), 0) == 0) { |
| @@ -2740,6 +2743,11 @@ void * __weak bpf_arch_text_copy(void *dst, void *src, size_t len) · 1766 unmodified lines | |||
| 2740 | return ERR_PTR(-ENOTSUPP); | 2743 | return ERR_PTR(-ENOTSUPP); |
| 2741 | } | 2744 | } |
| 2742 | 2745 | ||
| 2746 | int __weak bpf_arch_text_invalidate(void *dst, size_t len) | ||
| 2747 | { | ||
| 2748 | return -ENOTSUPP; | ||
| 2749 | } | ||
| 2750 | |||
| 2743 | DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key); | 2751 | DEFINE_STATIC_KEY_FALSE(bpf_stats_enabled_key); |
| 2744 | EXPORT_SYMBOL(bpf_stats_enabled_key); | 2752 | EXPORT_SYMBOL(bpf_stats_enabled_key); |
| 2745 | 2753 | ||