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path: root/arch/csky/kernel/ftrace.c
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2019-04-22csky/ftrace: Add dynamic function tracer (include graph tracer)Guo Ren
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>
2018-12-31csky: ftrace call graph supported.Guo Ren
With csky-gcc -pg -mbacktrace, ftrace call graph supported. Signed-off-by: Guo Ren <ren_guo@c-sky.com>
2018-12-31csky: basic ftrace supportedGuo Ren
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>