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author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2018-11-24 01:18:03 +0300 |
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committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-12-05 18:36:28 +0300 |
commit | dc002bb62f10c5905420f8b8a7d5ec0da567fc82 (patch) | |
tree | 2d5b812a9cb024a671bcda37431505d6dded1c47 | |
parent | 2a95471c3397734ba6869ca3fa084490fb35b40b (diff) | |
download | linux-dc002bb62f10c5905420f8b8a7d5ec0da567fc82.tar.xz |
bpf: add __weak hook for allocating executable memory
By default, BPF uses module_alloc() to allocate executable memory,
but this is not necessary on all arches and potentially undesirable
on some of them.
So break out the module_alloc() and module_memfree() calls into __weak
functions to allow them to be overridden in arch code.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
-rw-r--r-- | kernel/bpf/core.c | 14 |
1 files changed, 12 insertions, 2 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index f93ed667546f..86817ab204e8 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -623,6 +623,16 @@ static void bpf_jit_uncharge_modmem(u32 pages) atomic_long_sub(pages, &bpf_jit_current); } +void *__weak bpf_jit_alloc_exec(unsigned long size) +{ + return module_alloc(size); +} + +void __weak bpf_jit_free_exec(void *addr) +{ + module_memfree(addr); +} + struct bpf_binary_header * bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, unsigned int alignment, @@ -640,7 +650,7 @@ bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, if (bpf_jit_charge_modmem(pages)) return NULL; - hdr = module_alloc(size); + hdr = bpf_jit_alloc_exec(size); if (!hdr) { bpf_jit_uncharge_modmem(pages); return NULL; @@ -664,7 +674,7 @@ void bpf_jit_binary_free(struct bpf_binary_header *hdr) { u32 pages = hdr->pages; - module_memfree(hdr); + bpf_jit_free_exec(hdr); bpf_jit_uncharge_modmem(pages); } |