Please check CONFIG_FRAME_POINTER 1 *frame = *((struct stackframe *)frame->fp - 1); This code is origionally from riscv/kernel/stacktrace.c: walk_stackframe In linux/Makefile it'll involve the options for gcc to definitely store ra & prev_fp in fp pointer. ifdef CONFIG_FRAME_POINTER KBUILD_CFLAGS += -fno-omit-frame-pointer -fno-optimize-sibling-calls So --call-graph fp need depends on CONFIG_FRAME_POINTER. On Fri, Aug 23, 2019 at 4:56 PM Greentime Hu <green.hu@xxxxxxxxx> wrote: > > Hi Mao, > > Mao Han <han_mao@xxxxxxxxx> 於 2019年8月23日 週五 下午2:16寫道： > > > > > This patch add support for perf callchain sampling on riscv platform. > > The return address of leaf function is retrieved from pt_regs as > > it is not saved in the outmost frame. > > > > Signed-off-by: Mao Han <han_mao@xxxxxxxxx> > > Cc: Paul Walmsley <paul.walmsley@xxxxxxxxxx> > > Cc: Greentime Hu <green.hu@xxxxxxxxx> > > Cc: Palmer Dabbelt <palmer@xxxxxxxxxx> > > Cc: linux-riscv <linux-riscv@xxxxxxxxxxxxxxxxxxx> > > Cc: Christoph Hellwig <hch@xxxxxx> > > Cc: Guo Ren <guoren@xxxxxxxxxx> > > --- > > arch/riscv/Makefile | 3 + > > arch/riscv/kernel/Makefile | 3 +- > > arch/riscv/kernel/perf_callchain.c | 115 +++++++++++++++++++++++++++++++++++++ > > 3 files changed, 120 insertions(+), 1 deletion(-) > > create mode 100644 arch/riscv/kernel/perf_callchain.c > > I just tested "./perf record -e cpu-clock --call-graph fp ls" on > Unleashed board and I got this failure. > I take a look at it. It seem failed in here. Do you have any idea? > It seems fine in Qemu. > > 1 *frame = *((struct stackframe *)frame->fp - 1); > ffffffe0001a198c: 00863a83 ld s5,8(a2) > ffffffe0001a1990: ff093903 ld s2,-16(s2) > > ./perf record -e cpu-clock --call-graph fp ls > [ 9619.423884] hrtimer: interrupt took 733000 ns > [ 9619.977017] Unable to handle kernel paging request at virtual > address ffffffffffffff94 > [ 9620.214736] Oops [#1] > [ 9620.289893] Modules linked in: > [ 9620.391378] CPU: 0 PID: 264 Comm: ls Not tainted > 5.3.0-rc5-00003-gb008f6bcd67c #4 > [ 9620.640176] sepc: ffffffe0001a198c ra : ffffffe0001a199a sp : > ffffffe000093720 > [ 9620.880366] gp : ffffffe00097dad8 tp : ffffffe000082e40 t0 : 0000000000046000 > [ 9621.120564] t1 : 0000000000000002 t2 : 0000000000000007 s0 : ffffffe000093760 > [ 9621.360768] s1 : ffffffe000093788 a0 : 0000000000000003 a1 : 0000000000000000 > [ 9621.600991] a2 : ffffffffffffff8c a3 : 0000000000001fa0 a4 : 0000000000000010 > [ 9621.841181] a5 : 0000000000000002 a6 : 0000000000000001 a7 : ffffffe079b34e10 > [ 9622.081400] s2 : ffffffffffffff9c s3 : ffffffe000000000 s4 : 0000000000001ff8 > [ 9622.321618] s5 : ffffffe000093da0 s6 : ffffffe00097d540 s7 : ffffffe07a1517a0 > [ 9622.561811] s8 : 000008bf01c7ff60 s9 : ffffffe000235b2a s10: 0000000200000120 > [ 9622.802015] s11: 0000000000000001 t3 : ffffffe079b34e00 t4 : 0000000000000001 > [ 9623.042194] t5 : 0000000000000008 t6 : ffffffe0009208d0 > [ 9623.218785] sstatus: 0000000200000100 sbadaddr: ffffffffffffff94 > scause: 000000000000000d > [ 9623.490850] ---[ end trace 49043f28e856d84d ]--- > [ 9623.644217] Kernel panic - not syncing: Fatal exception in interrupt > [ 9623.855470] SMP: stopping secondary CPUs > [ 9623.985955] ---[ end Kernel panic - not syncing: Fatal exception in > interrupt ]--- -- Best Regards Guo Ren ML: https://lore.kernel.org/linux-csky/
