* [PATCH] arm64: ftrace: fix building without CONFIG_MODULES
@ 2017-06-09 10:27 Arnd Bergmann
2017-06-09 11:38 ` Will Deacon
0 siblings, 1 reply; 6+ messages in thread
From: Arnd Bergmann @ 2017-06-09 10:27 UTC (permalink / raw)
To: linux-arm-kernel
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(-)
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)
--
2.9.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* [PATCH] arm64: ftrace: fix building without CONFIG_MODULES 2017-06-09 10:27 [PATCH] arm64: ftrace: fix building without CONFIG_MODULES Arnd Bergmann @ 2017-06-09 11:38 ` Will Deacon 2017-06-09 18:57 ` Arnd Bergmann 0 siblings, 1 reply; 6+ messages in thread From: Will Deacon @ 2017-06-09 11:38 UTC (permalink / raw) To: linux-arm-kernel 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 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] arm64: ftrace: fix building without CONFIG_MODULES 2017-06-09 11:38 ` Will Deacon @ 2017-06-09 18:57 ` Arnd Bergmann 2017-06-12 12:48 ` Will Deacon 0 siblings, 1 reply; 6+ messages in thread From: Arnd Bergmann @ 2017-06-09 18:57 UTC (permalink / raw) To: linux-arm-kernel 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 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] arm64: ftrace: fix building without CONFIG_MODULES 2017-06-09 18:57 ` Arnd Bergmann @ 2017-06-12 12:48 ` Will Deacon 2017-06-12 13:01 ` Ard Biesheuvel 2017-06-12 14:22 ` Arnd Bergmann 0 siblings, 2 replies; 6+ messages in thread From: Will Deacon @ 2017-06-12 12:48 UTC (permalink / raw) To: linux-arm-kernel On Fri, Jun 09, 2017 at 08:57:31PM +0200, Arnd Bergmann wrote: > On Fri, Jun 9, 2017 at 1:38 PM, Will Deacon <will.deacon@arm.com> wrote: > > 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 Thanks, I was forgetting to enable ftrace. I think a simpler patch (and one that I can just apply via arm64) is switching the IS_ENABLEDs out for #ifdefs. See below. Will --->8 diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c index 8a42be0693c9..401aa27808a4 100644 --- a/arch/arm64/kernel/ftrace.c +++ b/arch/arm64/kernel/ftrace.c @@ -71,11 +71,12 @@ int ftrace_update_ftrace_func(ftrace_func_t func) int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) { unsigned long pc = rec->ip; - long offset = (long)pc - (long)addr; u32 old, new; - if (IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) && - (offset < -SZ_128M || offset >= SZ_128M)) { +#ifdef CONFIG_ARM64_MODULE_PLTS + long offset = (long)pc - (long)addr; + + if (offset < -SZ_128M || offset >= SZ_128M) { unsigned long *trampoline; struct module *mod; @@ -121,6 +122,7 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) } addr = (unsigned long)&trampoline[1]; } +#endif /* CONFIG_ARM64_MODULE_PLTS */ old = aarch64_insn_gen_nop(); new = aarch64_insn_gen_branch_imm(pc, addr, AARCH64_INSN_BRANCH_LINK); @@ -135,12 +137,13 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr) { unsigned long pc = rec->ip; - long offset = (long)pc - (long)addr; bool validate = true; u32 old = 0, new; - if (IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) && - (offset < -SZ_128M || offset >= SZ_128M)) { +#ifdef CONFIG_ARM64_MODULE_PLTS + long offset = (long)pc - (long)addr; + + if (offset < -SZ_128M || offset >= SZ_128M) { u32 replaced; /* @@ -177,6 +180,7 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, old = aarch64_insn_gen_branch_imm(pc, addr, AARCH64_INSN_BRANCH_LINK); } +#endif /* CONFIG_ARM64_MODULE_PLTS */ new = aarch64_insn_gen_nop(); ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH] arm64: ftrace: fix building without CONFIG_MODULES 2017-06-12 12:48 ` Will Deacon @ 2017-06-12 13:01 ` Ard Biesheuvel 2017-06-12 14:22 ` Arnd Bergmann 1 sibling, 0 replies; 6+ messages in thread From: Ard Biesheuvel @ 2017-06-12 13:01 UTC (permalink / raw) To: linux-arm-kernel On 12 June 2017 at 14:48, Will Deacon <will.deacon@arm.com> wrote: > On Fri, Jun 09, 2017 at 08:57:31PM +0200, Arnd Bergmann wrote: >> On Fri, Jun 9, 2017 at 1:38 PM, Will Deacon <will.deacon@arm.com> wrote: >> > 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 > > Thanks, I was forgetting to enable ftrace. I think a simpler patch (and one > that I can just apply via arm64) is switching the IS_ENABLEDs out for > #ifdefs. I agree that this makes more sense in this particular case. Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Interestingly, ARM64_MODULE_PLTS does not depend on CONFIG_MODULES, but I can't remember whether that was deliberate or an oversight. > See below. > > --->8 > > diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c > index 8a42be0693c9..401aa27808a4 100644 > --- a/arch/arm64/kernel/ftrace.c > +++ b/arch/arm64/kernel/ftrace.c > @@ -71,11 +71,12 @@ int ftrace_update_ftrace_func(ftrace_func_t func) > int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > { > unsigned long pc = rec->ip; > - long offset = (long)pc - (long)addr; > u32 old, new; > > - if (IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) && > - (offset < -SZ_128M || offset >= SZ_128M)) { > +#ifdef CONFIG_ARM64_MODULE_PLTS > + long offset = (long)pc - (long)addr; > + > + if (offset < -SZ_128M || offset >= SZ_128M) { > unsigned long *trampoline; > struct module *mod; > > @@ -121,6 +122,7 @@ int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr) > } > addr = (unsigned long)&trampoline[1]; > } > +#endif /* CONFIG_ARM64_MODULE_PLTS */ > > old = aarch64_insn_gen_nop(); > new = aarch64_insn_gen_branch_imm(pc, addr, AARCH64_INSN_BRANCH_LINK); > @@ -135,12 +137,13 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, > unsigned long addr) > { > unsigned long pc = rec->ip; > - long offset = (long)pc - (long)addr; > bool validate = true; > u32 old = 0, new; > > - if (IS_ENABLED(CONFIG_ARM64_MODULE_PLTS) && > - (offset < -SZ_128M || offset >= SZ_128M)) { > +#ifdef CONFIG_ARM64_MODULE_PLTS > + long offset = (long)pc - (long)addr; > + > + if (offset < -SZ_128M || offset >= SZ_128M) { > u32 replaced; > > /* > @@ -177,6 +180,7 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, > old = aarch64_insn_gen_branch_imm(pc, addr, > AARCH64_INSN_BRANCH_LINK); > } > +#endif /* CONFIG_ARM64_MODULE_PLTS */ > > new = aarch64_insn_gen_nop(); > ^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH] arm64: ftrace: fix building without CONFIG_MODULES 2017-06-12 12:48 ` Will Deacon 2017-06-12 13:01 ` Ard Biesheuvel @ 2017-06-12 14:22 ` Arnd Bergmann 1 sibling, 0 replies; 6+ messages in thread From: Arnd Bergmann @ 2017-06-12 14:22 UTC (permalink / raw) To: linux-arm-kernel On Mon, Jun 12, 2017 at 2:48 PM, Will Deacon <will.deacon@arm.com> wrote: > On Fri, Jun 09, 2017 at 08:57:31PM +0200, Arnd Bergmann wrote: >> On Fri, Jun 9, 2017 at 1:38 PM, Will Deacon <will.deacon@arm.com> wrote: >> > 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 > > Thanks, I was forgetting to enable ftrace. I think a simpler patch (and one > that I can just apply via arm64) is switching the IS_ENABLEDs out for > #ifdefs. See below. Yes, good idea. Arnd ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-06-12 14:22 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2017-06-09 10:27 [PATCH] arm64: ftrace: fix building without CONFIG_MODULES Arnd Bergmann 2017-06-09 11:38 ` Will Deacon 2017-06-09 18:57 ` Arnd Bergmann 2017-06-12 12:48 ` Will Deacon 2017-06-12 13:01 ` Ard Biesheuvel 2017-06-12 14:22 ` Arnd Bergmann
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