The patch titled modules: make module_address_lookup safe has been removed from the -mm tree. Its filename was modules-make-module_address_lookup-safe.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: modules: make module_address_lookup safe From: Rusty Russell <rusty@xxxxxxxxxxxxxxx> module_address_lookup releases preemption then returns a pointer into the module space. The only user (kallsyms) copies the result, so just do that under the preempt disable. Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: Kyle McMartin <kyle@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/module.h | 22 +++++++++++++--------- kernel/kallsyms.c | 11 ++++------- kernel/module.c | 20 ++++++++++++-------- 3 files changed, 29 insertions(+), 24 deletions(-) diff -puN include/linux/module.h~modules-make-module_address_lookup-safe include/linux/module.h --- a/include/linux/module.h~modules-make-module_address_lookup-safe +++ a/include/linux/module.h @@ -446,11 +446,14 @@ static inline void __module_get(struct m __mod ? __mod->name : "kernel"; \ }) -/* For kallsyms to ask for address resolution. NULL means not found. */ -const char *module_address_lookup(unsigned long addr, - unsigned long *symbolsize, - unsigned long *offset, - char **modname); +/* For kallsyms to ask for address resolution. namebuf should be at + * least KSYM_NAME_LEN long: a pointer to namebuf is returned if + * found, otherwise NULL. */ +char *module_address_lookup(unsigned long addr, + unsigned long *symbolsize, + unsigned long *offset, + char **modname, + char *namebuf); int lookup_module_symbol_name(unsigned long addr, char *symname); int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name); @@ -516,10 +519,11 @@ static inline void module_put(struct mod #define module_name(mod) "kernel" /* For kallsyms to ask for address resolution. NULL means not found. */ -static inline const char *module_address_lookup(unsigned long addr, - unsigned long *symbolsize, - unsigned long *offset, - char **modname) +static inline char *module_address_lookup(unsigned long addr, + unsigned long *symbolsize, + unsigned long *offset, + char **modname, + char *namebuf) { return NULL; } diff -puN kernel/kallsyms.c~modules-make-module_address_lookup-safe kernel/kallsyms.c --- a/kernel/kallsyms.c~modules-make-module_address_lookup-safe +++ a/kernel/kallsyms.c @@ -224,10 +224,11 @@ static unsigned long get_symbol_pos(unsi int kallsyms_lookup_size_offset(unsigned long addr, unsigned long *symbolsize, unsigned long *offset) { + char namebuf[KSYM_NAME_LEN]; if (is_ksym_addr(addr)) return !!get_symbol_pos(addr, symbolsize, offset); - return !!module_address_lookup(addr, symbolsize, offset, NULL); + return !!module_address_lookup(addr, symbolsize, offset, NULL, namebuf); } /* @@ -242,8 +243,6 @@ const char *kallsyms_lookup(unsigned lon unsigned long *offset, char **modname, char *namebuf) { - const char *msym; - namebuf[KSYM_NAME_LEN - 1] = 0; namebuf[0] = 0; @@ -259,10 +258,8 @@ const char *kallsyms_lookup(unsigned lon } /* see if it's in a module */ - msym = module_address_lookup(addr, symbolsize, offset, modname); - if (msym) - return strncpy(namebuf, msym, KSYM_NAME_LEN - 1); - + return module_address_lookup(addr, symbolsize, offset, modname, + namebuf); return NULL; } diff -puN kernel/module.c~modules-make-module_address_lookup-safe kernel/module.c --- a/kernel/module.c~modules-make-module_address_lookup-safe +++ a/kernel/module.c @@ -2211,14 +2211,13 @@ static const char *get_ksymbol(struct mo return mod->strtab + mod->symtab[best].st_name; } -/* For kallsyms to ask for address resolution. NULL means not found. - We don't lock, as this is used for oops resolution and races are a - lesser concern. */ -/* FIXME: Risky: returns a pointer into a module w/o lock */ -const char *module_address_lookup(unsigned long addr, - unsigned long *size, - unsigned long *offset, - char **modname) +/* For kallsyms to ask for address resolution. NULL means not found. Careful + * not to lock to avoid deadlock on oopses, simply disable preemption. */ +char *module_address_lookup(unsigned long addr, + unsigned long *size, + unsigned long *offset, + char **modname, + char *namebuf) { struct module *mod; const char *ret = NULL; @@ -2233,6 +2232,11 @@ const char *module_address_lookup(unsign break; } } + /* Make a copy in here where it's safe */ + if (ret) { + strncpy(namebuf, ret, KSYM_NAME_LEN - 1); + ret = namebuf; + } preempt_enable(); return ret; } _ Patches currently in -mm which might be from rusty@xxxxxxxxxxxxxxx are origin.patch git-kvm.patch request_irq-always-returns-einval-with-a-null-handler.patch kallsyms-should-prefer-non-weak-symbols.patch virtio_net-remove-double-ether_setup.patch modules-handle-symbols-that-have-a-zero-value.patch modules-include-sectionsh-to-avoid-defining-linker-variables.patch modules-make-module_address_lookup-safe-fix.patch fixup-container_of-usage.patch aio-partial-write-should-not-return-error-code.patch aio-negative-offset-should-return-einval.patch reiser4.patch - To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html