From 036b5560bebc72c61d955ae0b115e8e69da8a563 Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Thu, 20 May 2021 13:50:41 +0000 Subject: powerpc/inst: Avoid pointer dereferencing in ppc_inst_equal() Avoid casting/dereferencing ppc_inst() as u64* , check each member of the struct when relevant. And remove the 0xff initialisation of the suffix for non prefixed instruction. An instruction with 0xff as a suffix might be invalid, but still is a prefixed instruction and has to be considered as this. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/d8b155e930b7a9708ca110e8ff0ace6713a7af75.1621516826.git.christophe.leroy@csgroup.eu --- arch/powerpc/include/asm/inst.h | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) diff --git a/arch/powerpc/include/asm/inst.h b/arch/powerpc/include/asm/inst.h index dab26b0493d5..1ba65052ed21 100644 --- a/arch/powerpc/include/asm/inst.h +++ b/arch/powerpc/include/asm/inst.h @@ -61,7 +61,7 @@ static inline int ppc_inst_primary_opcode(struct ppc_inst x) } #ifdef CONFIG_PPC64 -#define ppc_inst(x) ((struct ppc_inst){ .val = (x), .suffix = 0xff }) +#define ppc_inst(x) ((struct ppc_inst){ .val = (x) }) #define ppc_inst_prefix(x, y) ((struct ppc_inst){ .val = (x), .suffix = (y) }) @@ -72,7 +72,7 @@ static inline u32 ppc_inst_suffix(struct ppc_inst x) static inline bool ppc_inst_prefixed(struct ppc_inst x) { - return ppc_inst_primary_opcode(x) == OP_PREFIX && ppc_inst_suffix(x) != 0xff; + return ppc_inst_primary_opcode(x) == OP_PREFIX; } static inline struct ppc_inst ppc_inst_swab(struct ppc_inst x) @@ -93,11 +93,6 @@ static inline struct ppc_inst ppc_inst_read(const struct ppc_inst *ptr) } } -static inline bool ppc_inst_equal(struct ppc_inst x, struct ppc_inst y) -{ - return *(u64 *)&x == *(u64 *)&y; -} - #else #define ppc_inst(x) ((struct ppc_inst){ .val = x }) @@ -124,13 +119,17 @@ static inline struct ppc_inst ppc_inst_read(const struct ppc_inst *ptr) return *ptr; } +#endif /* CONFIG_PPC64 */ + static inline bool ppc_inst_equal(struct ppc_inst x, struct ppc_inst y) { - return ppc_inst_val(x) == ppc_inst_val(y); + if (ppc_inst_val(x) != ppc_inst_val(y)) + return false; + if (!ppc_inst_prefixed(x)) + return true; + return ppc_inst_suffix(x) == ppc_inst_suffix(y); } -#endif /* CONFIG_PPC64 */ - static inline int ppc_inst_len(struct ppc_inst x) { return ppc_inst_prefixed(x) ? 8 : 4; -- cgit v1.2.3