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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id k14sm7556115pgt.8.2021.10.13.00.02.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 13 Oct 2021 00:02:13 -0700 (PDT) Date: Wed, 13 Oct 2021 00:02:12 -0700 From: Kees Cook To: Christophe Leroy Cc: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Andrew Morton , "James E.J. Bottomley" , Helge Deller , Arnd Bergmann , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v1 06/10] asm-generic: Refactor dereference_[kernel]_function_descriptor() Message-ID: <202110130002.A7C0A86@keescook> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 11, 2021 at 05:25:33PM +0200, Christophe Leroy wrote: > dereference_function_descriptor() and > dereference_kernel_function_descriptor() are identical on the > three architectures implementing them. > > Make it common. > > Signed-off-by: Christophe Leroy > --- > arch/ia64/include/asm/sections.h | 19 ------------------- > arch/parisc/include/asm/sections.h | 9 --------- > arch/parisc/kernel/process.c | 21 --------------------- > arch/powerpc/include/asm/sections.h | 23 ----------------------- > include/asm-generic/sections.h | 18 ++++++++++++++++++ > 5 files changed, 18 insertions(+), 72 deletions(-) A diffstat to love. :) Reviewed-by: Kees Cook > > diff --git a/arch/ia64/include/asm/sections.h b/arch/ia64/include/asm/sections.h > index 929b5c535620..d9addaea8339 100644 > --- a/arch/ia64/include/asm/sections.h > +++ b/arch/ia64/include/asm/sections.h > @@ -30,23 +30,4 @@ extern char __start_gate_brl_fsys_bubble_down_patchlist[], __end_gate_brl_fsys_b > extern char __start_unwind[], __end_unwind[]; > extern char __start_ivt_text[], __end_ivt_text[]; > > -#undef dereference_function_descriptor > -static inline void *dereference_function_descriptor(void *ptr) > -{ > - struct fdesc *desc = ptr; > - void *p; > - > - if (!get_kernel_nofault(p, (void *)&desc->addr)) > - ptr = p; > - return ptr; > -} > - > -#undef dereference_kernel_function_descriptor > -static inline void *dereference_kernel_function_descriptor(void *ptr) > -{ > - if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd) > - return ptr; > - return dereference_function_descriptor(ptr); > -} > - > #endif /* _ASM_IA64_SECTIONS_H */ > diff --git a/arch/parisc/include/asm/sections.h b/arch/parisc/include/asm/sections.h > index 329e80f7af0a..b041fb32a300 100644 > --- a/arch/parisc/include/asm/sections.h > +++ b/arch/parisc/include/asm/sections.h > @@ -12,13 +12,4 @@ typedef Elf64_Fdesc funct_descr_t; > > extern char __alt_instructions[], __alt_instructions_end[]; > > -#ifdef CONFIG_64BIT > - > -#undef dereference_function_descriptor > -void *dereference_function_descriptor(void *); > - > -#undef dereference_kernel_function_descriptor > -void *dereference_kernel_function_descriptor(void *); > -#endif > - > #endif > diff --git a/arch/parisc/kernel/process.c b/arch/parisc/kernel/process.c > index 38ec4ae81239..7382576b52a8 100644 > --- a/arch/parisc/kernel/process.c > +++ b/arch/parisc/kernel/process.c > @@ -266,27 +266,6 @@ get_wchan(struct task_struct *p) > return 0; > } > > -#ifdef CONFIG_64BIT > -void *dereference_function_descriptor(void *ptr) > -{ > - Elf64_Fdesc *desc = ptr; > - void *p; > - > - if (!get_kernel_nofault(p, (void *)&desc->addr)) > - ptr = p; > - return ptr; > -} > - > -void *dereference_kernel_function_descriptor(void *ptr) > -{ > - if (ptr < (void *)__start_opd || > - ptr >= (void *)__end_opd) > - return ptr; > - > - return dereference_function_descriptor(ptr); > -} > -#endif > - > static inline unsigned long brk_rnd(void) > { > return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT; > diff --git a/arch/powerpc/include/asm/sections.h b/arch/powerpc/include/asm/sections.h > index d0d5287fa568..8f8e95f234e2 100644 > --- a/arch/powerpc/include/asm/sections.h > +++ b/arch/powerpc/include/asm/sections.h > @@ -72,29 +72,6 @@ static inline int overlaps_kernel_text(unsigned long start, unsigned long end) > (unsigned long)_stext < end; > } > > -#ifdef PPC64_ELF_ABI_v1 > - > -#undef dereference_function_descriptor > -static inline void *dereference_function_descriptor(void *ptr) > -{ > - struct ppc64_opd_entry *desc = ptr; > - void *p; > - > - if (!get_kernel_nofault(p, (void *)&desc->addr)) > - ptr = p; > - return ptr; > -} > - > -#undef dereference_kernel_function_descriptor > -static inline void *dereference_kernel_function_descriptor(void *ptr) > -{ > - if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd) > - return ptr; > - > - return dereference_function_descriptor(ptr); > -} > -#endif /* PPC64_ELF_ABI_v1 */ > - > #endif > > #endif /* __KERNEL__ */ > diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h > index 436412d94054..5baaf9d7c671 100644 > --- a/include/asm-generic/sections.h > +++ b/include/asm-generic/sections.h > @@ -60,6 +60,24 @@ extern __visible const void __nosave_begin, __nosave_end; > > /* Function descriptor handling (if any). Override in asm/sections.h */ > #ifdef HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR > +static inline void *dereference_function_descriptor(void *ptr) > +{ > + funct_descr_t *desc = ptr; > + void *p; > + > + if (!get_kernel_nofault(p, (void *)&desc->addr)) > + ptr = p; > + return ptr; > +} > + > +static inline void *dereference_kernel_function_descriptor(void *ptr) > +{ > + if (ptr < (void *)__start_opd || ptr >= (void *)__end_opd) > + return ptr; > + > + return dereference_function_descriptor(ptr); > +} > + > #else > #define dereference_function_descriptor(p) ((void *)(p)) > #define dereference_kernel_function_descriptor(p) ((void *)(p)) > -- > 2.31.1 > -- Kees Cook