[PATCH] arm64: fix endianness annotation for 'struct jit_ctx' and friends

[PATCH] arm64: fix endianness annotation for 'struct jit_ctx' and friends

[Luc Van Oostenryck]

struct jit_ctx::image is used the store a pointer to the jitted
intructions, which are always little-endian. These instructions
are thus correctly converted from native order to little-endian
before being stored but the pointer 'image' is declared as for
native order values.

Fix this by declaring the field as __le32* instead of u32*.
Same for the pointer used in jit_fill_hole() to initialize
the image.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
---
 arch/arm64/net/bpf_jit_comp.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index c870d6f01..8860bb9c3 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -70,7 +70,7 @@ struct jit_ctx {
 	int idx;
 	int epilogue_offset;
 	int *offset;
-	u32 *image;
+	__le32 *image;
 };
 
 static inline void emit(const u32 insn, struct jit_ctx *ctx)
@@ -130,7 +130,7 @@ static inline int bpf2a64_offset(int bpf_to, int bpf_from,
 
 static void jit_fill_hole(void *area, unsigned int size)
 {
-	u32 *ptr;
+	__le32 *ptr;
 	/* We are guaranteed to have aligned memory. */
 	for (ptr = area; size >= sizeof(u32); size -= sizeof(u32))
 		*ptr++ = cpu_to_le32(AARCH64_BREAK_FAULT);
@@ -874,7 +874,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog)
 
 	/* 2. Now, the actual pass. */
 
-	ctx.image = (u32 *)image_ptr;
+	ctx.image = (__le32 *)image_ptr;
 	ctx.idx = 0;
 
 	build_prologue(&ctx);
-- 
2.13.0

[PATCH] arm64: fix endianness annotation for 'struct jit_ctx' and friends

[Will Deacon]

On Wed, Jun 28, 2017 at 04:58:03PM +0200, Luc Van Oostenryck wrote:
> struct jit_ctx::image is used the store a pointer to the jitted
> intructions, which are always little-endian. These instructions
> are thus correctly converted from native order to little-endian
> before being stored but the pointer 'image' is declared as for
> native order values.
> 
> Fix this by declaring the field as __le32* instead of u32*.
> Same for the pointer used in jit_fill_hole() to initialize
> the image.
> 
> Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
> ---
>  arch/arm64/net/bpf_jit_comp.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)

Happy to take this via the arm64 tree, along with the other sparse fixes
(modulo review comments).

Ok with you, David?

Will

[PATCH] arm64: fix endianness annotation for 'struct jit_ctx' and friends

[Luc Van Oostenryck]

On Thu, Jun 29, 2017 at 11:08:36AM +0100, Will Deacon wrote:
> Happy to take this via the arm64 tree, along with the other sparse fixes
> (modulo review comments).

For info, together with the other endianness fixes I sent, this
fixes all the 'easy to fix' endianness annotations.

It remains:
- 2 or 3 small issues, just needing a cast, maybe with __force.
- Problems with probes. Those could probably be fixed
  by redefining [k]probe_opcode_t as __le32 instead of u32
  but I didn't looked at the consequences.
- 3 or 4 'impossible to solve properly by design' where things
  like the following is done:
	if (kvm_vcpu_is_be(vcpu)) {
		switch (len) {
		case 1:
			return data & 0xff;
		case 2:
			return be16_to_cpu(data & 0xffff);
		case 4:
			return be32_to_cpu(data & 0xffffffff);
		default:
			return be64_to_cpu(data);
		}
	} else {
		...
  This is done for kvm emulate & the kvm vgics


Cheers,
-- Luc