Hello! On 3/13/21 9:41 AM, Huang Pei wrote: > From: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx> > > On some architectures, the DYNAMIC_FTRACE_WITH_REGS is implemented by > gcc's -fpatchable-function-entry option. Take arm64 for example, arm64 > makes use of GCC -fpatchable-function-entry=2 option to insert two > nops. When the function is traced, the first nop will be modified to > the LR saver, then the second nop to "bl <ftrace-entry>". we need to > update ftrace_location() to recognise these two instructions as being > part of ftrace. To do this, we introduce FTRACE_IP_EXTENSION to let > ftrace_location search IP, IP + FTRACE_IP_EXTENSION range. > > Signed-off-by: Jisheng Zhang <Jisheng.Zhang@xxxxxxxxxxxxx> > Suggested-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> > --- > include/linux/ftrace.h | 4 ++++ > kernel/trace/ftrace.c | 2 +- > 2 files changed, 5 insertions(+), 1 deletion(-) > > diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h > index 1bd3a0356ae4..c1e1fbde8a04 100644 > --- a/include/linux/ftrace.h > +++ b/include/linux/ftrace.h > @@ -20,6 +20,10 @@ > > #include <asm/ftrace.h> > > +#ifndef FTRACE_IP_EXTENSION > +#define FTRACE_IP_EXTENSION 0 Inconsistent spacing between #<directive> and the value? [...] MBR, Sergei
