Messages in this thread | | | From | Jordan Niethe <> | Date | Tue, 15 Jun 2021 13:38:06 +1000 | Subject | Re: [PATCH v2 04/12] powerpc/inst: Avoid pointer dereferencing in ppc_inst_equal() |
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On Thu, May 20, 2021 at 11:50 PM Christophe Leroy <christophe.leroy@csgroup.eu> wrote: > > 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 <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 fc6adef528a5..5a0740ebf132 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; > -- > 2.25.0 > Reviewed by: Jordan Niethe <jniethe5@gmail.com>
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