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commit 4f7656fe8ed94d07f7de9a4274cd2a47675fb178
Author: Andrew Cooper <andrew.cooper3@citrix.com>
AuthorDate: Sun Apr 16 01:10:43 2023 +0100
Commit: Andrew Cooper <andrew.cooper3@citrix.com>
CommitDate: Tue Apr 9 12:56:55 2024 +0100

arm/alternatives: Rename alt_instr fields which are used in common code

Alternatives auditing for livepatches is currently broken. To fix it, the
livepatch code needs to inspect more fields of alt_instr.

Rename ARM's fields to match x86's, because:

* ARM already exposes alt_offset under the repl name via ALT_REPL_PTR().
* "alt" is ambiguous in a structure entirely about alternatives already.
* "repl", being the same width as orig leads to slightly neater code.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
(cherry picked from commit 418cf59c4e29451010d7efb3835b900690d19866)
---
xen/arch/arm/alternative.c | 6 +++---
xen/arch/arm/include/asm/alternative.h | 12 ++++++------
2 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/xen/arch/arm/alternative.c b/xen/arch/arm/alternative.c
index f03cd943c6..ef98f37417 100644
--- a/xen/arch/arm/alternative.c
+++ b/xen/arch/arm/alternative.c
@@ -55,7 +55,7 @@ static bool branch_insn_requires_update(const struct alt_instr *alt,
return true;

replptr = (unsigned long)ALT_REPL_PTR(alt);
- if ( pc >= replptr && pc <= (replptr + alt->alt_len) )
+ if ( pc >= replptr && pc <= (replptr + alt->repl_len) )
return false;

/*
@@ -139,9 +139,9 @@ static int __apply_alternatives(const struct alt_region *region,
continue;

if ( alt->cpufeature == ARM_CB_PATCH )
- BUG_ON(alt->alt_len != 0);
+ BUG_ON(alt->repl_len != 0);
else
- BUG_ON(alt->alt_len != alt->orig_len);
+ BUG_ON(alt->repl_len != alt->orig_len);

origptr = ALT_ORIG_PTR(alt);
updptr = (void *)origptr + update_offset;
diff --git a/xen/arch/arm/include/asm/alternative.h b/xen/arch/arm/include/asm/alternative.h
index 1eb4b60fbb..d3210e82f9 100644
--- a/xen/arch/arm/include/asm/alternative.h
+++ b/xen/arch/arm/include/asm/alternative.h
@@ -13,16 +13,16 @@

struct alt_instr {
s32 orig_offset; /* offset to original instruction */
- s32 alt_offset; /* offset to replacement instruction */
+ s32 repl_offset; /* offset to replacement instruction */
u16 cpufeature; /* cpufeature bit set for replacement */
u8 orig_len; /* size of original instruction(s) */
- u8 alt_len; /* size of new instruction(s), <= orig_len */
+ u8 repl_len; /* size of new instruction(s), <= orig_len */
};

/* Xen: helpers used by common code. */
#define __ALT_PTR(a,f) ((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)
+#define ALT_REPL_PTR(a) __ALT_PTR(a, repl_offset)

typedef void (*alternative_cb_t)(const struct alt_instr *alt,
const uint32_t *origptr, uint32_t *updptr,
@@ -90,12 +90,12 @@ int apply_alternatives(const struct alt_instr *start, const struct alt_instr *en
#include <asm/asm_defns.h>
#include <asm/macros.h>

-.macro altinstruction_entry orig_offset alt_offset feature orig_len alt_len
+.macro altinstruction_entry orig_offset repl_offset feature orig_len repl_len
.word \orig_offset - .
- .word \alt_offset - .
+ .word \repl_offset - .
.hword \feature
.byte \orig_len
- .byte \alt_len
+ .byte \repl_len
.endm

.macro alternative_insn insn1, insn2, cap, enable = 1
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.17