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riscv: bpf: Avoid breaking W^X

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We allocate Non-executable pages, then call bpf_jit_binary_lock_ro()
to enable executable permission after mapping them read-only. This is
to prepare for STRICT_MODULE_RWX in following patch.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
This commit is contained in:
Jisheng Zhang 2021-03-30 02:25:21 +08:00 committed by Palmer Dabbelt
parent 1d27d85442
commit fc8504765e
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1 changed files with 2 additions and 1 deletions
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arch/riscv/net/bpf_jit_core.c
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@ -152,6 +152,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
bpf_flush_icache(jit_data->header, ctx->insns + ctx->ninsns); bpf_flush_icache(jit_data->header, ctx->insns + ctx->ninsns);
if (!prog->is_func || extra_pass) { if (!prog->is_func || extra_pass) {
bpf_jit_binary_lock_ro(jit_data->header);
out_offset: out_offset:
kfree(ctx->offset); kfree(ctx->offset);
kfree(jit_data); kfree(jit_data);
@ -169,7 +170,7 @@ void *bpf_jit_alloc_exec(unsigned long size)
{ {
return __vmalloc_node_range(size, PAGE_SIZE, BPF_JIT_REGION_START, return __vmalloc_node_range(size, PAGE_SIZE, BPF_JIT_REGION_START,
BPF_JIT_REGION_END, GFP_KERNEL, BPF_JIT_REGION_END, GFP_KERNEL,
PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE, PAGE_KERNEL, 0, NUMA_NO_NODE,
__builtin_return_address(0)); __builtin_return_address(0));
} }