Messages in this thread | | | Date | Tue, 5 Oct 2021 15:08:07 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH][next] ftrace: Fix -Wcast-function-type warnings on powerpc64 |
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On Tue, 5 Oct 2021 11:50:27 -0500 "Gustavo A. R. Silva" <gustavoars@kernel.org> wrote:
> On Tue, Oct 05, 2021 at 12:35:22PM -0400, Steven Rostedt wrote: > > On Tue, 5 Oct 2021 11:18:12 -0500 > > "Gustavo A. R. Silva" <gustavoars@kernel.org> wrote: > > > > > On Tue, Oct 05, 2021 at 11:17:14AM -0400, Steven Rostedt wrote: > > > > On Tue, 5 Oct 2021 00:39:22 -0500 > > > > "Gustavo A. R. Silva" <gustavoars@kernel.org> wrote: > > > > > > > > > In order to make sure new function cast mismatches are not introduced > > > > > in the kernel (to avoid tripping CFI checking), the kernel should be > > > > > globally built with -Wcast-function-type. > > > > > > > > > > So, fix the following -Wcast-function-type warnings on powerpc64 > > > > > (ppc64_defconfig): > > > > > > > > I think I'll go back and add my linker magic. > > > > > > > > https://lore.kernel.org/all/20200617165616.52241bde@oasis.local.home/ > > > > > > > > I'll clean it up a bit too. I'll have a patch in a bit. > > > > > > Awesome. :) > > > > > > Thanks > > > -- > > > > Does this fix it for you? > > Nop; there are still some warnings (ppc64_defconfig):
Sure you applied it?
Because I tested it on powerpc64 with the defconfig, and without the patch, I get the error, but with it, I don't.
> > kernel/trace/ftrace.c: In function ‘ftrace_ops_get_list_func’: > kernel/trace/ftrace.c:171:10: error: returning ‘void (*)(long unsigned int, long unsigned int, struct ftrace_ops *, struct ftrace_regs *)’ from a function with incompatible return type ‘ftrace_func_t’ {aka ‘void (*)(long unsigned int, long unsigned int)’} [-Werror=incompatible-pointer-types] > 171 | return ftrace_ops_list_func; > | ^~~~~~~~~~~~~~~~~~~~
Or did you not remove your patch first?
Because, the above error shows:
return type ‘ftrace_func_t’ {aka ‘void (*)(long unsigned int, long unsigned int)’
But my code has:
typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs);
Which is not the same type, but your patch has:
+#if ARCH_SUPPORTS_FTRACE_OPS typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs); +#else +typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip); +#endif + +typedef void (*ftrace_func_base_t)(void); +#define CAST_FTRACE_FUNC(f) ((ftrace_func_t)((ftrace_func_base_t)(f)))
Which redefines ftrace_func_t.
-- Steve
> kernel/trace/ftrace.c: In function ‘update_ftrace_function’: > kernel/trace/ftrace.c:204:8: error: assignment to ‘ftrace_func_t’ {aka ‘void (*)(long unsigned int, long unsigned int)’} from incompatible pointer type ‘void (*)(long unsigned int, long unsigned int, struct ftrace_ops *, struct ftrace_regs *)’ [-Werror=incompatible-pointer-types] > 204 | func = ftrace_ops_list_func; > | ^ > kernel/trace/ftrace.c:217:11: warning: comparison of distinct pointer types lacks a cast > 217 | if (func == ftrace_ops_list_func) { > | ^~ > kernel/trace/ftrace.c: In function ‘ftrace_modify_all_code’: > kernel/trace/ftrace.c:2695:35: error: passing argument 1 of ‘ftrace_update_ftrace_func’ from incompatible pointer type [-Werror=incompatible-pointer-types] > 2695 | err = ftrace_update_ftrace_func(ftrace_ops_list_func); > | ^~~~~~~~~~~~~~~~~~~~ > | | > | void (*)(long unsigned int, long unsigned int, struct ftrace_ops *, struct ftrace_regs *) > In file included from kernel/trace/ftrace.c:29: > ./include/linux/ftrace.h:585:52: note: expected ‘ftrace_func_t’ {aka ‘void (*)(long unsigned int, long unsigned int)’} but argument is of type ‘void (*)(long unsigned int, long unsigned int, struct ftrace_ops *, struct ftrace_regs *)’ > 585 | extern int ftrace_update_ftrace_func(ftrace_func_t func); > | ~~~~~~~~~~~~~~^~~~ > kernel/trace/ftrace.c:2705:38: warning: comparison of distinct pointer types lacks a cast > 2705 | if (update && ftrace_trace_function != ftrace_ops_list_func) { > | ^~ > > -- > Gustavo
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