Re: [PATCH v2 08/14] objtool: Fix JUMP_ENTRY_SIZE for bi-arch like powerpc
From: Peter Zijlstra <peterz@infradead.org>
Date: 2023-06-22 11:45:03
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lkml
On Thu, Jun 22, 2023 at 12:54:30PM +0200, Christophe Leroy wrote:
struct jump_entry {
s32 code;
s32 target;
long key;
};
It means that the size of the third argument depends on
whether we are building a 32 bits or 64 bits kernel.
Therefore JUMP_ENTRY_SIZE must depend on elf_class_addrsize(elf).
To allow that, entries[] table must be initialised at runtime. This is
easily done by moving it into its only user which is special_get_alts().
Signed-off-by: Christophe Leroy <redacted>Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> However, it doesn't apply to tip/objtool/core because Josh went and renamed a bunch of things including elf_class_addrsize(). It's now elf_addr_siize().
quoted hunk ↗ jump to hunk
--- .../arch/powerpc/include/arch/special.h | 2 +- tools/objtool/special.c | 55 +++++++++---------- 2 files changed, 28 insertions(+), 29 deletions(-)diff --git a/tools/objtool/arch/powerpc/include/arch/special.h b/tools/objtool/arch/powerpc/include/arch/special.h index ffef9ada7133..ede05633c2e4 100644 --- a/tools/objtool/arch/powerpc/include/arch/special.h +++ b/tools/objtool/arch/powerpc/include/arch/special.h@@ -6,7 +6,7 @@ #define EX_ORIG_OFFSET 0 #define EX_NEW_OFFSET 4 -#define JUMP_ENTRY_SIZE 16 +#define JUMP_ENTRY_SIZE (8 + elf_class_addrsize(elf)) /* 12 on PPC32, 16 on PPC64 */ #define JUMP_ORIG_OFFSET 0 #define JUMP_NEW_OFFSET 4 #define JUMP_KEY_OFFSET 8diff --git a/tools/objtool/special.c b/tools/objtool/special.c index baa85c31526b..4015c1cd0fe1 100644 --- a/tools/objtool/special.c +++ b/tools/objtool/special.c@@ -26,34 +26,6 @@ struct special_entry { unsigned char key; /* jump_label key */ }; -static const struct special_entry entries[] = { - { - .sec = ".altinstructions", - .group = true, - .size = ALT_ENTRY_SIZE, - .orig = ALT_ORIG_OFFSET, - .orig_len = ALT_ORIG_LEN_OFFSET, - .new = ALT_NEW_OFFSET, - .new_len = ALT_NEW_LEN_OFFSET, - .feature = ALT_FEATURE_OFFSET, - }, - { - .sec = "__jump_table", - .jump_or_nop = true, - .size = JUMP_ENTRY_SIZE, - .orig = JUMP_ORIG_OFFSET, - .new = JUMP_NEW_OFFSET, - .key = JUMP_KEY_OFFSET, - }, - { - .sec = "__ex_table", - .size = EX_ENTRY_SIZE, - .orig = EX_ORIG_OFFSET, - .new = EX_NEW_OFFSET, - }, - {}, -}; - void __weak arch_handle_alternative(unsigned short feature, struct special_alt *alt) { }@@ -144,6 +116,33 @@ int special_get_alts(struct elf *elf, struct list_head *alts) unsigned int nr_entries; struct special_alt *alt; int idx, ret; + const struct special_entry entries[] = { + { + .sec = ".altinstructions", + .group = true, + .size = ALT_ENTRY_SIZE, + .orig = ALT_ORIG_OFFSET, + .orig_len = ALT_ORIG_LEN_OFFSET, + .new = ALT_NEW_OFFSET, + .new_len = ALT_NEW_LEN_OFFSET, + .feature = ALT_FEATURE_OFFSET, + }, + { + .sec = "__jump_table", + .jump_or_nop = true, + .size = JUMP_ENTRY_SIZE, + .orig = JUMP_ORIG_OFFSET, + .new = JUMP_NEW_OFFSET, + .key = JUMP_KEY_OFFSET, + }, + { + .sec = "__ex_table", + .size = EX_ENTRY_SIZE, + .orig = EX_ORIG_OFFSET, + .new = EX_NEW_OFFSET, + }, + {}, + }; INIT_LIST_HEAD(alts);-- 2.40.1