From ad6561dffa17f17bb68d7207d422c26c381c4313 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Fri, 12 Jun 2009 21:47:03 -0600 Subject: module: trim exception table on init free. It's theoretically possible that there are exception table entries which point into the (freed) init text of modules. These could cause future problems if other modules get loaded into that memory and cause an exception as we'd see the wrong fixup. The only case I know of is kvm-intel.ko (when CONFIG_CC_OPTIMIZE_FOR_SIZE=n). Amerigo fixed this long-standing FIXME in the x86 version, but this patch is more general. This implements trim_init_extable(); most archs are simple since they use the standard lib/extable.c sort code. Alpha and IA64 use relative addresses in their fixups, so thier trimming is a slight variation. Sparc32 is unique; it doesn't seem to define ARCH_HAS_SORT_EXTABLE, yet it defines its own sort_extable() which overrides the one in lib. It doesn't sort, so we have to mark deleted entries instead of actually trimming them. Inspired-by: Amerigo Wang Signed-off-by: Rusty Russell Cc: linux-alpha@vger.kernel.org Cc: sparclinux@vger.kernel.org Cc: linux-ia64@vger.kernel.org --- include/linux/module.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index a8f2c0aa4c32..a7bc6e7b43a7 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -77,6 +77,7 @@ search_extable(const struct exception_table_entry *first, void sort_extable(struct exception_table_entry *start, struct exception_table_entry *finish); void sort_main_extable(void); +void trim_init_extable(struct module *m); #ifdef MODULE #define MODULE_GENERIC_TABLE(gtype,name) \ -- cgit v1.3-14-g43fede From 0d9c25dde878a636ee9a9b53923569171bf9a55b Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Tue, 16 Jun 2009 15:33:37 -0700 Subject: headers: move module_bug_finalize()/module_bug_cleanup() definitions into module.h They're in linux/bug.h at present, which causes include order tangles. In particular, linux/bug.h cannot be used by linux/atomic.h because, according to Nikanth: linux/bug.h pulls in linux/module.h => linux/spinlock.h => asm/spinlock.h (which uses atomic_inc) => asm/atomic.h. bug.h is a pretty low-level thing and module.h is a higher-level thing, IMO. Cc: Nikanth Karthikesan Cc: Rusty Russell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/bug.h | 12 ------------ include/linux/module.h | 17 +++++++++++++++++ 2 files changed, 17 insertions(+), 12 deletions(-) (limited to 'include/linux/module.h') diff --git a/include/linux/bug.h b/include/linux/bug.h index 54398d2c6d8d..d276b5510c83 100644 --- a/include/linux/bug.h +++ b/include/linux/bug.h @@ -1,7 +1,6 @@ #ifndef _LINUX_BUG_H #define _LINUX_BUG_H -#include #include enum bug_trap_type { @@ -24,10 +23,6 @@ const struct bug_entry *find_bug(unsigned long bugaddr); enum bug_trap_type report_bug(unsigned long bug_addr, struct pt_regs *regs); -int module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *, - struct module *); -void module_bug_cleanup(struct module *); - /* These are defined by the architecture */ int is_valid_bugaddr(unsigned long addr); @@ -38,13 +33,6 @@ static inline enum bug_trap_type report_bug(unsigned long bug_addr, { return BUG_TRAP_TYPE_BUG; } -static inline int module_bug_finalize(const Elf_Ehdr *hdr, - const Elf_Shdr *sechdrs, - struct module *mod) -{ - return 0; -} -static inline void module_bug_cleanup(struct module *mod) {} #endif /* CONFIG_GENERIC_BUG */ #endif /* _LINUX_BUG_H */ diff --git a/include/linux/module.h b/include/linux/module.h index a7bc6e7b43a7..505f20dcc1c7 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -697,4 +697,21 @@ static inline void module_remove_modinfo_attrs(struct module *mod) #define __MODULE_STRING(x) __stringify(x) + +#ifdef CONFIG_GENERIC_BUG +int module_bug_finalize(const Elf_Ehdr *, const Elf_Shdr *, + struct module *); +void module_bug_cleanup(struct module *); + +#else /* !CONFIG_GENERIC_BUG */ + +static inline int module_bug_finalize(const Elf_Ehdr *hdr, + const Elf_Shdr *sechdrs, + struct module *mod) +{ + return 0; +} +static inline void module_bug_cleanup(struct module *mod) {} +#endif /* CONFIG_GENERIC_BUG */ + #endif /* _LINUX_MODULE_H */ -- cgit v1.3-14-g43fede