--- v11
+++ v10
@@ -1,41 +1,66 @@
-Commit 74451e66d516 ("bpf: make jited programs visible in traces") added
-a default bpf_jit_free() implementation. Powerpc did not use the default
-bpf_jit_free() as powerpc did not set the images read-only. The default
-bpf_jit_free() called bpf_jit_binary_unlock_ro() is why it could not be
-used for powerpc.
+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.
-Commit d53d2f78cead ("bpf: Use vmalloc special flag") moved keeping
-track of read-only memory to vmalloc. This included removing
-bpf_jit_binary_unlock_ro(). Therefore there is no reason powerpc needs
-its own bpf_jit_free(). Remove it.
+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>
---
-v11: New to series
+v10: New to series
---
- arch/powerpc/net/bpf_jit_comp.c | 12 ------------
- 1 file changed, 12 deletions(-)
+ 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 798ac4350a82..6c8c268e4fe8 100644
+index e809cb5a1631..8015e4a7d2d4 100644
--- a/arch/powerpc/net/bpf_jit_comp.c
+++ b/arch/powerpc/net/bpf_jit_comp.c
-@@ -257,15 +257,3 @@ 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);
- return fp;
+ 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));
++ 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. */
--void bpf_jit_free(struct bpf_prog *fp)
--{
-- unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK;
-- struct bpf_binary_header *bpf_hdr = (void *)addr;
--
-- if (fp->jited)
-- bpf_jit_binary_free(bpf_hdr);
--
-- bpf_prog_unlock_free(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