[PATCH 7/9] riscv: bpf: Avoid breaking W^X
From: Jisheng Zhang <hidden>
Date: 2021-03-29 18:31:17
Also in:
bpf, linux-riscv, lkml
Subsystem:
bpf jit for risc-v (32-bit), bpf jit for risc-v (64-bit), bpf [general] (safe dynamic programs and tools), risc-v architecture, the rest · Maintainers:
Luke Nelson, Xi Wang, Björn Töpel, Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Paul Walmsley, Palmer Dabbelt, Albert Ou, Linus Torvalds
From: Jisheng Zhang <jszhang@kernel.org> 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> --- arch/riscv/net/bpf_jit_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/riscv/net/bpf_jit_core.c b/arch/riscv/net/bpf_jit_core.c
index d8da819290b7..0d5099f0dac8 100644
--- a/arch/riscv/net/bpf_jit_core.c
+++ b/arch/riscv/net/bpf_jit_core.c@@ -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); if (!prog->is_func || extra_pass) { + bpf_jit_binary_lock_ro(header); out_offset: kfree(ctx->offset); 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, BPF_JIT_REGION_END, GFP_KERNEL, - PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE, + PAGE_KERNEL, 0, NUMA_NO_NODE, __builtin_return_address(0)); }
--
2.31.0