From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-x242.google.com (mail-pf0-x242.google.com [IPv6:2607:f8b0:400e:c00::242]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3yY0KS75BszDrKr for ; Fri, 10 Nov 2017 10:50:36 +1100 (AEDT) Received: by mail-pf0-x242.google.com with SMTP id n89so5420011pfk.11 for ; Thu, 09 Nov 2017 15:50:36 -0800 (PST) From: Sergey Senozhatsky To: Tony Luck , Fenghua Yu , Helge Deller , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , James Bottomley Cc: Andrew Morton , Jessica Yu , Petr Mladek , Steven Rostedt , linux-ia64@vger.kernel.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Sergey Senozhatsky , Sergey Senozhatsky Subject: [PATCHv4 2/6] ia64: Add .opd based function descriptor dereference Date: Fri, 10 Nov 2017 08:48:26 +0900 Message-Id: <20171109234830.5067-3-sergey.senozhatsky@gmail.com> In-Reply-To: <20171109234830.5067-1-sergey.senozhatsky@gmail.com> References: <20171109234830.5067-1-sergey.senozhatsky@gmail.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , We are moving towards separate kernel and module function descriptor dereference callbacks. This patch enables it for IA64. For pointers that belong to the kernel - Added __start_opd and __end_opd pointers, to track the kernel .opd section address range; - Added dereference_kernel_function_descriptor(). Now we will dereference only function pointers that are within [__start_opd, __end_opd); For pointers that belong to a module - Added dereference_module_function_descriptor() to handle module function descriptor dereference. Now we will dereference only pointers that are within [module->opd.start, module->opd.end). Signed-off-by: Sergey Senozhatsky --- arch/ia64/include/asm/sections.h | 10 +++++++++- arch/ia64/kernel/module.c | 12 ++++++++++++ arch/ia64/kernel/vmlinux.lds.S | 2 ++ 3 files changed, 23 insertions(+), 1 deletion(-) diff --git a/arch/ia64/include/asm/sections.h b/arch/ia64/include/asm/sections.h index f3481408594e..cea15f2dd38d 100644 --- a/arch/ia64/include/asm/sections.h +++ b/arch/ia64/include/asm/sections.h @@ -27,6 +27,8 @@ 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[]; +#define HAVE_DEREFERENCE_FUNCTION_DESCRIPTOR 1 + #undef dereference_function_descriptor static inline void *dereference_function_descriptor(void *ptr) { @@ -38,6 +40,12 @@ static inline void *dereference_function_descriptor(void *ptr) 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/ia64/kernel/module.c b/arch/ia64/kernel/module.c index 853b5611a894..326448f9df16 100644 --- a/arch/ia64/kernel/module.c +++ b/arch/ia64/kernel/module.c @@ -36,6 +36,7 @@ #include #include +#include #define ARCH_MODULE_DEBUG 0 @@ -918,3 +919,14 @@ module_arch_cleanup (struct module *mod) if (mod->arch.core_unw_table) unw_remove_unwind_table(mod->arch.core_unw_table); } + +void *dereference_module_function_descriptor(struct module *mod, void *ptr) +{ + Elf64_Shdr *opd = mod->arch.opd; + + if (ptr < (void *)opd->sh_addr || + ptr >= (void *)(opd->sh_addr + opd->sh_size)) + return ptr; + + return dereference_function_descriptor(ptr); +} diff --git a/arch/ia64/kernel/vmlinux.lds.S b/arch/ia64/kernel/vmlinux.lds.S index 58db59da0bd8..31e688981b4b 100644 --- a/arch/ia64/kernel/vmlinux.lds.S +++ b/arch/ia64/kernel/vmlinux.lds.S @@ -108,7 +108,9 @@ SECTIONS { RODATA .opd : AT(ADDR(.opd) - LOAD_OFFSET) { + __start_opd = .; *(.opd) + __end_opd = .; } /* -- 2.15.0