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| author | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2019-10-15 16:00:55 +0300 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2019-11-14 21:13:43 +0300 |
| commit | b83b43ffc6e4b514ca034a0fbdee01322e2f7022 (patch) | |
| tree | 8e8d830664e6faf98589f241bd0ccba44802f8c8 /arch/sh | |
| parent | 953ae45a0c25e09428d4a03d7654f97ab8a36647 (diff) | |
| download | linux-b83b43ffc6e4b514ca034a0fbdee01322e2f7022.tar.xz | |
fgraph: Fix function type mismatches of ftrace_graph_return using ftrace_stub
The C compiler is allowing more checks to make sure that function pointers
are assigned to the correct prototype function. Unfortunately, the function
graph tracer uses a special name with its assigned ftrace_graph_return
function pointer that maps to a stub function used by the function tracer
(ftrace_stub). The ftrace_graph_return variable is compared to the
ftrace_stub in some archs to know if the function graph tracer is enabled or
not. This means we can not just simply create a new function stub that
compares it without modifying all the archs.
Instead, have the linker script create a function_graph_stub that maps to
ftrace_stub, and this way we can define the prototype for it to match the
prototype of ftrace_graph_return, and make the compiler checks all happy!
Link: http://lkml.kernel.org/r/20191015090055.789a0aed@gandalf.local.home
Cc: linux-sh@vger.kernel.org
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Reported-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'arch/sh')
| -rw-r--r-- | arch/sh/boot/compressed/misc.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/sh/boot/compressed/misc.c b/arch/sh/boot/compressed/misc.c index c15cac9251b9..e69ec12cbbe6 100644 --- a/arch/sh/boot/compressed/misc.c +++ b/arch/sh/boot/compressed/misc.c @@ -111,6 +111,11 @@ void __stack_chk_fail(void) error("stack-protector: Kernel stack is corrupted\n"); } +/* Needed because vmlinux.lds.h references this */ +void ftrace_stub(void) +{ +} + #ifdef CONFIG_SUPERH64 #define stackalign 8 #else |