The prototype for prepare_ftrace_return() is architecture specific and
can't be in a global header. Since it's normally called from assembly,
it doesn't really need a prototype, but we get a warning if it's missing:
arch/csky/kernel/ftrace.c:147:6: error: no previous prototype for 'prepare_ftrace_return' [-Werror=missing-prototypes]
arch/microblaze/kernel/ftrace.c:22:6: error: no previous prototype for 'prepare_ftrace_return' [-Werror=missing-prototypes]
arch/mips/kernel/ftrace.c:305:6: error: no previous prototype for 'prepare_ftrace_return' [-Werror=missing-prototypes]
Add the prototypes for the three architectures that don't already have
one in asm/ftrace.h.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
: error: C++ style comments are not allowed in ISO C90
// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
^
error: (this will be reported only once per input file)
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
This patch implements FTRACE_WITH_REGS for csky, which allows a traced
function's arguments (and some other registers) to be captured into a
struct pt_regs, allowing these to be inspected and/or modified.
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Support dynamic ftrace including dynamic graph tracer. Gcc-csky with -pg
will produce call site in every function prologue and we can use these
call site to hook trace function.
gcc with -pg origin call site:
push lr
jbsr _mcount
nop32
nop32
If the (callee - caller)'s offset is in range of bsr instruction, we'll
modify code with:
push lr
bsr _mcount
nop32
nop32
Else if the (callee - caller)'s offset is out of bsr instrunction, we'll
modify code with:
push lr
movih r26, ...
ori r26, ...
jsr r26
(r26 is reserved for jsr link reg in csky abiv2 spec.)
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
When gcc with -pg, it'll add _mcount stub in every function. We need
implement the _mcount in kernel and ftrace depends on stackstrace.
To do: call-graph, dynamic ftrace
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
