[v2,03/20] x86/arm64: Expose the ALT_[ORIG|REPL]_PTR macros to header files.

Commit Message

Konrad Rzeszutek Wilk Aug. 25, 2016, 1:37 p.m. UTC

That way common code can use the same macro to access
the most common attributes without much #ifdef.

Take advantage of it right away in the livepatch code.

Note: on ARM we use tabs to conform to the style of the file.

Acked-by: Jan Beulich <[e-mail]>
Signed-off-by: Konrad Rzeszutek Wilk <[e-mail]>

---
Cc: Stefano Stabellini <[e-mail]>
Cc: Julien Grall <[e-mail]>
Cc: Jan Beulich <[e-mail]>
Cc: Andrew Cooper <[e-mail]>

v1: First submission
v2: Added Jan's Ack
    Added extra set of paranetheses for __ALT_PTR (x86 & ARM)
    Used tabs instead of spaces on ARM header file.
---
 xen/arch/arm/alternative.c        | 4 ----
 xen/common/livepatch.c            | 4 ++--
 xen/include/asm-arm/alternative.h | 5 +++++
 xen/include/asm-x86/alternative.h | 4 ++++
 4 files changed, 11 insertions(+), 6 deletions(-)

Comments

Julien Grall Aug. 31, 2016, 3:43 p.m. UTC | #1

Hi Konrad,

On 25/08/16 14:37, Konrad Rzeszutek Wilk wrote:
> That way common code can use the same macro to access
> the most common attributes without much #ifdef.
>
> Take advantage of it right away in the livepatch code.
>
> Note: on ARM we use tabs to conform to the style of the file.
>
> Acked-by: Jan Beulich <[e-mail]>
> Signed-off-by: Konrad Rzeszutek Wilk <[e-mail]>

Acked-by: Julien Grall <[e-mail]>

Regards,

Patch

diff --git a/xen/arch/arm/alternative.c b/xen/arch/arm/alternative.c
index 8ee5a11..bf4101c 100644
--- a/xen/arch/arm/alternative.c
+++ b/xen/arch/arm/alternative.c
@@ -32,10 +32,6 @@ 
 #include <asm/insn.h>
 #include <asm/page.h>
 
-#define __ALT_PTR(a,f)      (u32 *)((void *)&(a)->f + (a)->f)
-#define ALT_ORIG_PTR(a)     __ALT_PTR(a, orig_offset)
-#define ALT_REPL_PTR(a)     __ALT_PTR(a, alt_offset)
-
 extern const struct alt_instr __alt_instructions[], __alt_instructions_end[];
 
 struct alt_region {
diff --git a/xen/common/livepatch.c b/xen/common/livepatch.c
index 528c0c9..774a51d 100644
--- a/xen/common/livepatch.c
+++ b/xen/common/livepatch.c
@@ -702,8 +702,8 @@  static int prepare_payload(struct payload *payload,
 
         for ( a = start; a < end; a++ )
         {
-            const void *instr = &a->instr_offset + a->instr_offset;
-            const void *replacement = &a->repl_offset + a->repl_offset;
+            const void *instr = ALT_ORIG_PTR(a);
+            const void *replacement = ALT_REPL_PTR(a);
 
             if ( (instr < region->start && instr >= region->end) ||
                  (replacement < region->start && replacement >= region->end) )
diff --git a/xen/include/asm-arm/alternative.h b/xen/include/asm-arm/alternative.h
index 4287bac..f25d3a7 100644
--- a/xen/include/asm-arm/alternative.h
+++ b/xen/include/asm-arm/alternative.h
@@ -21,6 +21,11 @@  struct alt_instr {
 	u8  alt_len;		/* size of new instruction(s), <= orig_len */
 };
 
+/* Xen: helpers used by common code. */
+#define __ALT_PTR(a,f)		((u32 *)((void *)&(a)->f + (a)->f))
+#define ALT_ORIG_PTR(a)		__ALT_PTR(a, orig_offset)
+#define ALT_REPL_PTR(a)		__ALT_PTR(a, alt_offset)
+
 void __init apply_alternatives_all(void);
 int apply_alternatives(void *start, size_t length);
 
diff --git a/xen/include/asm-x86/alternative.h b/xen/include/asm-x86/alternative.h
index acaeded..de807c8 100644
--- a/xen/include/asm-x86/alternative.h
+++ b/xen/include/asm-x86/alternative.h
@@ -23,6 +23,10 @@  struct alt_instr {
     u8  replacementlen;     /* length of new instruction, <= instrlen */
 };
 
+#define __ALT_PTR(a,f)      ((u8 *)((void *)&(a)->f + (a)->f))
+#define ALT_ORIG_PTR(a)     __ALT_PTR(a, instr_offset)
+#define ALT_REPL_PTR(a)     __ALT_PTR(a, repl_offset)
+
 extern void add_nops(void *insns, unsigned int len);
 /* Similar to apply_alternatives except it can be run with IRQs enabled. */
 extern void apply_alternatives_nocheck(struct alt_instr *start,