| Message ID | 20211013181658.1020262-7-samitolvanen@google.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | x86: Add support for Clang CFI | expand |
On Wed, Oct 13, 2021 at 11:16:49AM -0700, Sami Tolvanen wrote: > With CONFIG_CFI_CLANG, the compiler changes function references to > point to the CFI jump table. As ftrace_call, ftrace_regs_call, and > mcount_call are not called by C code, but are trampolines injected > as calls replacing the nops at the start of functions added by the > compiler, use DECLARE_NOT_CALLED_FROM_C to declare them. > > Signed-off-by: Sami Tolvanen <samitolvanen@google.com> Looks right to me... Reviewed-by: Kees Cook <keescook@chromium.org>
On Wed, 13 Oct 2021 11:16:49 -0700 Sami Tolvanen <samitolvanen@google.com> wrote: > With CONFIG_CFI_CLANG, the compiler changes function references to > point to the CFI jump table. As ftrace_call, ftrace_regs_call, and > mcount_call are not called by C code, but are trampolines injected > as calls replacing the nops at the start of functions added by the > compiler, use DECLARE_NOT_CALLED_FROM_C to declare them. > > Signed-off-by: Sami Tolvanen <samitolvanen@google.com> > Tested-by: Nick Desaulniers <ndesaulniers@google.com> > Tested-by: Sedat Dilek <sedat.dilek@gmail.com> > --- > include/linux/ftrace.h | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h > index 832e65f06754..c53a00b96ba9 100644 > --- a/include/linux/ftrace.h > +++ b/include/linux/ftrace.h > @@ -578,9 +578,10 @@ extern void ftrace_replace_code(int enable); > extern int ftrace_update_ftrace_func(ftrace_func_t func); > extern void ftrace_caller(void); > extern void ftrace_regs_caller(void); > -extern void ftrace_call(void); > -extern void ftrace_regs_call(void); > -extern void mcount_call(void); > + > +DECLARE_NOT_CALLED_FROM_C(ftrace_call); > +DECLARE_NOT_CALLED_FROM_C(ftrace_regs_call); > +DECLARE_NOT_CALLED_FROM_C(mcount_call); > > void ftrace_modify_all_code(int command); > Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> -- Steve
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 832e65f06754..c53a00b96ba9 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -578,9 +578,10 @@ extern void ftrace_replace_code(int enable); extern int ftrace_update_ftrace_func(ftrace_func_t func); extern void ftrace_caller(void); extern void ftrace_regs_caller(void); -extern void ftrace_call(void); -extern void ftrace_regs_call(void); -extern void mcount_call(void); + +DECLARE_NOT_CALLED_FROM_C(ftrace_call); +DECLARE_NOT_CALLED_FROM_C(ftrace_regs_call); +DECLARE_NOT_CALLED_FROM_C(mcount_call); void ftrace_modify_all_code(int command);