Re: [PATCH 5/6] ftrace: introduce FTRACE_IP_EXTENSION
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From: Sergei Shtylyov <hidden>
Date: 2021-03-13 09:49:57
Also in:
linux-mips, linux-mm
Hello! On 3/13/21 9:41 AM, Huang Pei wrote:
quoted hunk ↗ jump to hunk
From: Jisheng Zhang <redacted> 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 <redacted> Suggested-by: Steven Rostedt (VMware) <rostedt@goodmis.org> --- 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