--- v12
+++ v10
@@ -1,30 +1,66 @@
-Add the necessary call to bpf_jit_binary_lock_ro() to remove write and
-add exec permissions to the JIT image after it has finished being
-written.
+Once CONFIG_STRICT_MODULE_RWX is enabled there will be no need to
+override bpf_jit_free() because it is now possible to set images
+read-only. So use the default implementation.
-Without CONFIG_STRICT_MODULE_RWX the image will be writable and
-executable until the call to bpf_jit_binary_lock_ro().
+Also add the necessary call to bpf_jit_binary_lock_ro() which will
+remove write protection and add exec protection to the JIT image after
+it has finished being written.
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
---
v10: New to series
-v11: Remove CONFIG_STRICT_MODULE_RWX conditional
---
- arch/powerpc/net/bpf_jit_comp.c | 1 +
- 1 file changed, 1 insertion(+)
+ arch/powerpc/net/bpf_jit_comp.c | 5 ++++-
+ arch/powerpc/net/bpf_jit_comp64.c | 4 ++++
+ 2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
-index 6c8c268e4fe8..53aefee3fe70 100644
+index e809cb5a1631..8015e4a7d2d4 100644
--- a/arch/powerpc/net/bpf_jit_comp.c
+++ b/arch/powerpc/net/bpf_jit_comp.c
-@@ -237,6 +237,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
+@@ -659,12 +659,15 @@ void bpf_jit_compile(struct bpf_prog *fp)
+ bpf_jit_dump(flen, proglen, pass, code_base);
+
+ bpf_flush_icache(code_base, code_base + (proglen/4));
+-
+ #ifdef CONFIG_PPC64
+ /* Function descriptor nastiness: Address + TOC */
+ ((u64 *)image)[0] = (u64)code_base;
+ ((u64 *)image)[1] = local_paca->kernel_toc;
+ #endif
++ if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX)) {
++ set_memory_ro((unsigned long)image, alloclen >> PAGE_SHIFT);
++ set_memory_x((unsigned long)image, alloclen >> PAGE_SHIFT);
++ }
+
+ fp->bpf_func = (void *)image;
+ fp->jited = 1;
+diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c
+index aaf1a887f653..1484ad588685 100644
+--- a/arch/powerpc/net/bpf_jit_comp64.c
++++ b/arch/powerpc/net/bpf_jit_comp64.c
+@@ -1240,6 +1240,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
fp->jited_len = alloclen;
bpf_flush_icache(bpf_hdr, (u8 *)bpf_hdr + (bpf_hdr->pages * PAGE_SIZE));
-+ bpf_jit_binary_lock_ro(bpf_hdr);
++ if (IS_ENABLED(CONFIG_STRICT_MODULE_RWX))
++ bpf_jit_binary_lock_ro(bpf_hdr);
if (!fp->is_func || extra_pass) {
bpf_prog_fill_jited_linfo(fp, addrs);
out_addrs:
+@@ -1262,6 +1264,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp)
+ }
+
+ /* Overriding bpf_jit_free() as we don't set images read-only. */
++#ifndef CONFIG_STRICT_MODULE_RWX
+ void bpf_jit_free(struct bpf_prog *fp)
+ {
+ unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK;
+@@ -1272,3 +1275,4 @@ void bpf_jit_free(struct bpf_prog *fp)
+
+ bpf_prog_unlock_free(fp);
+ }
++#endif
--
2.25.1