| Message ID | 20170609102807.2992510-1-arnd@arndb.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Arnd, On Fri, Jun 09, 2017 at 12:27:06PM +0200, Arnd Bergmann wrote: > When CONFIG_MODULES is disabled, we cannot dereference a module pointer: > > arch/arm64/kernel/ftrace.c: In function 'ftrace_make_call': > arch/arm64/kernel/ftrace.c:107:36: error: dereferencing pointer to incomplete type 'struct module' > trampoline = (unsigned long *)mod->arch.ftrace_trampoline; > > Also, the within_module() function is not defined: > > arch/arm64/kernel/ftrace.c: In function 'ftrace_make_nop': > arch/arm64/kernel/ftrace.c:171:8: error: implicit declaration of function 'within_module'; did you mean 'init_module'? [-Werror=implicit-function-declaration] > > This addresses both by adding the appropriate stubs. > > Fixes: e71a4e1bebaf ("arm64: ftrace: add support for far branches to dynamic ftrace") > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > arch/arm64/include/asm/module.h | 6 ++++++ > arch/arm64/kernel/ftrace.c | 2 +- > include/linux/module.h | 5 +++++ > 3 files changed, 12 insertions(+), 1 deletion(-) I can't seem to reproduce this simply by disabling MODULES in defconfig. Could you share your .config, please? Will
On Fri, Jun 9, 2017 at 1:38 PM, Will Deacon <will.deacon@arm.com> wrote: > Hi Arnd, > > On Fri, Jun 09, 2017 at 12:27:06PM +0200, Arnd Bergmann wrote: >> When CONFIG_MODULES is disabled, we cannot dereference a module pointer: >> >> arch/arm64/kernel/ftrace.c: In function 'ftrace_make_call': >> arch/arm64/kernel/ftrace.c:107:36: error: dereferencing pointer to incomplete type 'struct module' >> trampoline = (unsigned long *)mod->arch.ftrace_trampoline; >> >> Also, the within_module() function is not defined: >> >> arch/arm64/kernel/ftrace.c: In function 'ftrace_make_nop': >> arch/arm64/kernel/ftrace.c:171:8: error: implicit declaration of function 'within_module'; did you mean 'init_module'? [-Werror=implicit-function-declaration] >> >> This addresses both by adding the appropriate stubs. >> >> Fixes: e71a4e1bebaf ("arm64: ftrace: add support for far branches to dynamic ftrace") >> Signed-off-by: Arnd Bergmann <arnd@arndb.de> >> --- >> arch/arm64/include/asm/module.h | 6 ++++++ >> arch/arm64/kernel/ftrace.c | 2 +- >> include/linux/module.h | 5 +++++ >> 3 files changed, 12 insertions(+), 1 deletion(-) > > I can't seem to reproduce this simply by disabling MODULES in defconfig. > Could you share your .config, please? This is the randconfig I used: https://pastebin.com/SfKBY7f8 Arnd
diff --git a/arch/arm64/include/asm/module.h b/arch/arm64/include/asm/module.h index 19bd97671bb8..ca5d024f4247 100644 --- a/arch/arm64/include/asm/module.h +++ b/arch/arm64/include/asm/module.h @@ -36,6 +36,12 @@ struct mod_arch_specific { }; #endif +#if defined(CONFIG_MODULES) && defined(CONFIG_ARM64_MODULE_PLTS) +#define module_ftrace_trampoline(mod) ((mod)->arch.ftrace_trampoline) +#else +#define module_ftrace_trampoline(mod) NULL +#endif + u64 module_emit_plt_entry(struct module *mod, void *loc, const Elf64_Rela *rela, Elf64_Sym *sym); diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c index 8a42be0693c9..7f5eb9939a55 100644 --- a/arch/arm64/kernel/ftrace.c +++ b/arch/arm64/kernel/ftrace.c @@ -104,7 +104,7 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) * is added in the future, but for now, the pr_err() below * deals with a theoretical issue only. */ - trampoline = (unsigned long *)mod->arch.ftrace_trampoline; + trampoline = module_ftrace_trampoline(mod); if (trampoline[0] != addr) { if (trampoline[0] != 0) { pr_err("ftrace: far branches to multiple entry points unsupported inside a single module\n"); diff --git a/include/linux/module.h b/include/linux/module.h index 21f56393602f..9196f532f158 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -671,6 +671,11 @@ static inline bool is_module_text_address(unsigned long addr) return false; } +static inline bool within_module(unsigned long addr, const struct module *mod) +{ + return false; +} + /* Get/put a kernel symbol (calls should be symmetric) */ #define symbol_get(x) ({ extern typeof(x) x __attribute__((weak)); &(x); }) #define symbol_put(x) do { } while (0)
When CONFIG_MODULES is disabled, we cannot dereference a module pointer: arch/arm64/kernel/ftrace.c: In function 'ftrace_make_call': arch/arm64/kernel/ftrace.c:107:36: error: dereferencing pointer to incomplete type 'struct module' trampoline = (unsigned long *)mod->arch.ftrace_trampoline; Also, the within_module() function is not defined: arch/arm64/kernel/ftrace.c: In function 'ftrace_make_nop': arch/arm64/kernel/ftrace.c:171:8: error: implicit declaration of function 'within_module'; did you mean 'init_module'? [-Werror=implicit-function-declaration] This addresses both by adding the appropriate stubs. Fixes: e71a4e1bebaf ("arm64: ftrace: add support for far branches to dynamic ftrace") Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- arch/arm64/include/asm/module.h | 6 ++++++ arch/arm64/kernel/ftrace.c | 2 +- include/linux/module.h | 5 +++++ 3 files changed, 12 insertions(+), 1 deletion(-)