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[V3,0/3] riscv: Add perf callchain support

Message ID cover.1558081981.git.han_mao@c-sky.com (mailing list archive)
Headers show
Series riscv: Add perf callchain support | expand

Message

Mao Han May 17, 2019, 8:43 a.m. UTC
This patch set add perf callchain(FP/DWARF) support for RISC-V.
It comes from the csky version callchain support with some
slight modifications. The patchset base on Linux 5.1.

CC: Palmer Dabbelt <palmer@sifive.com>
CC: linux-riscv <linux-riscv@lists.infradead.org>
CC: Christoph Hellwig <hch@lst.de>
CC: Guo Ren <guoren@kernel.org>

Changes since v2:
  - fix inconsistent comment
  - force to build kernel with -fno-omit-frame-pointer if perf
    event is enabled

Changes since v1:
  - simplify implementation and code convention

Mao Han (3):
  riscv: Add perf callchain support
  riscv: Add support for perf registers sampling
  riscv: Add support for libdw

 arch/riscv/Kconfig                            |   2 +
 arch/riscv/Makefile                           |   3 +
 arch/riscv/include/uapi/asm/perf_regs.h       |  42 ++++++++++
 arch/riscv/kernel/Makefile                    |   4 +-
 arch/riscv/kernel/perf_callchain.c            | 113 ++++++++++++++++++++++++++
 arch/riscv/kernel/perf_regs.c                 |  44 ++++++++++
 tools/arch/riscv/include/uapi/asm/perf_regs.h |  42 ++++++++++
 tools/perf/Makefile.config                    |   6 +-
 tools/perf/arch/riscv/Build                   |   1 +
 tools/perf/arch/riscv/Makefile                |   3 +
 tools/perf/arch/riscv/include/perf_regs.h     |  96 ++++++++++++++++++++++
 tools/perf/arch/riscv/util/Build              |   2 +
 tools/perf/arch/riscv/util/dwarf-regs.c       |  72 ++++++++++++++++
 tools/perf/arch/riscv/util/unwind-libdw.c     |  57 +++++++++++++
 14 files changed, 485 insertions(+), 2 deletions(-)
 create mode 100644 arch/riscv/include/uapi/asm/perf_regs.h
 create mode 100644 arch/riscv/kernel/perf_callchain.c
 create mode 100644 arch/riscv/kernel/perf_regs.c
 create mode 100644 tools/arch/riscv/include/uapi/asm/perf_regs.h
 create mode 100644 tools/perf/arch/riscv/Build
 create mode 100644 tools/perf/arch/riscv/Makefile
 create mode 100644 tools/perf/arch/riscv/include/perf_regs.h
 create mode 100644 tools/perf/arch/riscv/util/Build
 create mode 100644 tools/perf/arch/riscv/util/dwarf-regs.c
 create mode 100644 tools/perf/arch/riscv/util/unwind-libdw.c

Comments

Mao Han June 3, 2019, 8:33 a.m. UTC | #1
PING?
On Fri, May 17, 2019 at 04:43:01PM +0800, Mao Han wrote:
> This patch set add perf callchain(FP/DWARF) support for RISC-V.
> It comes from the csky version callchain support with some
> slight modifications. The patchset base on Linux 5.1.
> 
> CC: Palmer Dabbelt <palmer@sifive.com>
> CC: linux-riscv <linux-riscv@lists.infradead.org>
> CC: Christoph Hellwig <hch@lst.de>
> CC: Guo Ren <guoren@kernel.org>
> 
> Changes since v2:
>   - fix inconsistent comment
>   - force to build kernel with -fno-omit-frame-pointer if perf
>     event is enabled
> 
> Changes since v1:
>   - simplify implementation and code convention
> 
> Mao Han (3):
>   riscv: Add perf callchain support
>   riscv: Add support for perf registers sampling
>   riscv: Add support for libdw
> 
>  arch/riscv/Kconfig                            |   2 +
>  arch/riscv/Makefile                           |   3 +
>  arch/riscv/include/uapi/asm/perf_regs.h       |  42 ++++++++++
>  arch/riscv/kernel/Makefile                    |   4 +-
>  arch/riscv/kernel/perf_callchain.c            | 113 ++++++++++++++++++++++++++
>  arch/riscv/kernel/perf_regs.c                 |  44 ++++++++++
>  tools/arch/riscv/include/uapi/asm/perf_regs.h |  42 ++++++++++
>  tools/perf/Makefile.config                    |   6 +-
>  tools/perf/arch/riscv/Build                   |   1 +
>  tools/perf/arch/riscv/Makefile                |   3 +
>  tools/perf/arch/riscv/include/perf_regs.h     |  96 ++++++++++++++++++++++
>  tools/perf/arch/riscv/util/Build              |   2 +
>  tools/perf/arch/riscv/util/dwarf-regs.c       |  72 ++++++++++++++++
>  tools/perf/arch/riscv/util/unwind-libdw.c     |  57 +++++++++++++
>  14 files changed, 485 insertions(+), 2 deletions(-)
>  create mode 100644 arch/riscv/include/uapi/asm/perf_regs.h
>  create mode 100644 arch/riscv/kernel/perf_callchain.c
>  create mode 100644 arch/riscv/kernel/perf_regs.c
>  create mode 100644 tools/arch/riscv/include/uapi/asm/perf_regs.h
>  create mode 100644 tools/perf/arch/riscv/Build
>  create mode 100644 tools/perf/arch/riscv/Makefile
>  create mode 100644 tools/perf/arch/riscv/include/perf_regs.h
>  create mode 100644 tools/perf/arch/riscv/util/Build
>  create mode 100644 tools/perf/arch/riscv/util/dwarf-regs.c
>  create mode 100644 tools/perf/arch/riscv/util/unwind-libdw.c
> 
> -- 
> 2.7.4
> 
> 
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv
Paul Walmsley Aug. 16, 2019, 5:14 p.m. UTC | #2
Hello Mao Han,

On Fri, 17 May 2019, Mao Han wrote:

> This patch set add perf callchain(FP/DWARF) support for RISC-V.
> It comes from the csky version callchain support with some
> slight modifications. The patchset base on Linux 5.1.
> 
> CC: Palmer Dabbelt <palmer@sifive.com>
> CC: linux-riscv <linux-riscv@lists.infradead.org>
> CC: Christoph Hellwig <hch@lst.de>
> CC: Guo Ren <guoren@kernel.org>

I tried these patches on v5.3-rc4, both on the HiFive Unleashed board 
with a Debian-based rootfs and QEMU rv64 with a Fedora-based rootfs.  For 
QEMU, I used defconfig, and for the HiFive Unleashed, I added a few more 
Kconfig directives; and on both, I enabled CONFIG_PERF_EVENTS.  I built 
the perf tools from the kernel tree.

Upon running "/root/bin/perf record -e cpu-clock --call-graph fp 
/bin/ls", I see the backtraces below.  The first is on the HiFive 
Unleashed, the second is on QEMU.  

Could you take a look and tell me if you see similar issues?  And if not, 
could you please walk me through your process for testing these patches on 
rv64, so I can reproduce it here?


thanks,

- Paul


# /root/bin/perf record -e cpu-clock --call-graph fp /bin/ls
[  213.258888] Unable to handle kernel paging request at virtual address ffffffd2d979000c
[  213.266025] Oops [#1]
[  213.268278] Modules linked in:
[  213.271323] CPU: 2 PID: 165 Comm: ls Not tainted 5.3.0-rc4-00006-g2615b94055fc #164
[  213.278961] sepc: ffffffe0005bde76 ra : ffffffe0005bde84 sp : ffffffe1f609d870
[  213.286166]  gp : ffffffe000dbe6c0 tp : ffffffe1f60fa600 t0 : 0000000000046000
[  213.293372]  t1 : 0000000000000002 t2 : 0000002aaaac4890 s0 : ffffffe1f609d8b0
[  213.300579]  s1 : ffffffe1f609d8d8 a0 : 0000000000000004 a1 : 0000000000000000
[  213.307785]  a2 : 10ef8552d9790004 a3 : 0000000000000018 a4 : 0000000000000018
[  213.314991]  a5 : 0000000000000003 a6 : 0000000000000001 a7 : ffffffe1f7b685e0
[  213.322198]  s2 : 10ef8552d9790014 s3 : 0000003fffffffff s4 : 0000000000001ff8
[  213.329404]  s5 : b7e9595db7f9e15f s6 : ffffffe000dbe128 s7 : ffffffe1f8d6f820
[  213.336610]  s8 : 00000031a394a3e8 s9 : ffffffe000656150 s10: 0000000200000120
[  213.343816]  s11: 0000002aaaabc938 t3 : ffffffe1f7b685c0 t4 : 0000000000000001
[  213.351021]  t5 : 0000000000000008 t6 : 0000000000000000
[  213.356319] sstatus: 0000000200000100 sbadaddr: ffffffd2d979000c scause: 000000000000000d
[  213.364482] ---[ end trace f325867b8e0786aa ]---
[  213.369083] Kernel panic - not syncing: Fatal exception in interrupt
[  213.375421] SMP: stopping secondary CPUs
[  213.379336] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---


# /root/bin/perf record -e cpu-clock --call-graph fp /bin/ls
[ 3465.349655] Unable to handle kernel paging request at virtual address d9bfd43b47718688
[ 3465.352356] Oops [#1]
[ 3465.353375] Modules linked in:
[ 3465.354496] CPU: 0 PID: 9501 Comm: ls Not tainted 5.3.0-rc4-00004-g3bfea1b43363 #165
[ 3465.355904] sepc: ffffffe000039a0a ra : ffffffe000039a18 sp : ffffffe078c5b5e0
[ 3465.361041]  gp : ffffffe000837760 tp : ffffffe078d88940 t0 : 0000000000046000
[ 3465.366104]  t1 : 0000000000000002 t2 : 000000004387194a s0 : ffffffe078c5b620
[ 3465.366839]  s1 : ffffffe078c5b648 a0 : 0000000000000004 a1 : 0000000000000000
[ 3465.369101]  a2 : d9bfd43b47718680 a3 : 0000000000000690 a4 : 0000000000000018
[ 3465.370949]  a5 : 0000000000000003 a6 : 0000000000000001 a7 : ffffffe0743b16d0
[ 3465.371650]  s2 : d9bfd43b47718690 s3 : 0000003fffffffff s4 : 0000000000001ff8
[ 3465.372658]  s5 : e85970cf9e9fbbc8 s6 : ffffffe0008371c8 s7 : ffffffe07a1527a0
[ 3465.373570]  s8 : 00000326c7b3d418 s9 : ffffffe0000d3326 s10: 0000000000000120
[ 3465.377102]  s11: ffffffe078cb4880 t3 : ffffffe0743b16c0 t4 : 0000000000000001
[ 3465.378125]  t5 : 0000000000000008 t6 : ffffffe078c5bd60
[ 3465.380603] sstatus: 0000000000000100 sbadaddr: d9bfd43b47718688 scause: 000000000000000d
[ 3465.382872] ---[ end trace f0ff9969d564eb82 ]---
[ 3465.383998] Kernel panic - not syncing: Fatal exception in interrupt
[ 3465.385812] SMP: stopping secondary CPUs
[ 3465.394408] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---
Mao Han Aug. 19, 2019, 8:18 a.m. UTC | #3
Hi Paul,
On Fri, Aug 16, 2019 at 10:14:01AM -0700, Paul Walmsley wrote:
> Hello Mao Han,
> 
> On Fri, 17 May 2019, Mao Han wrote:
> 
> > This patch set add perf callchain(FP/DWARF) support for RISC-V.
> > It comes from the csky version callchain support with some
> > slight modifications. The patchset base on Linux 5.1.
> > 
> > CC: Palmer Dabbelt <palmer@sifive.com>
> > CC: linux-riscv <linux-riscv@lists.infradead.org>
> > CC: Christoph Hellwig <hch@lst.de>
> > CC: Guo Ren <guoren@kernel.org>
> 
> I tried these patches on v5.3-rc4, both on the HiFive Unleashed board 
> with a Debian-based rootfs and QEMU rv64 with a Fedora-based rootfs.  For 
> QEMU, I used defconfig, and for the HiFive Unleashed, I added a few more 
> Kconfig directives; and on both, I enabled CONFIG_PERF_EVENTS.  I built 
> the perf tools from the kernel tree.
> 
> Upon running "/root/bin/perf record -e cpu-clock --call-graph fp 
> /bin/ls", I see the backtraces below.  The first is on the HiFive 
> Unleashed, the second is on QEMU.  
> 
> Could you take a look and tell me if you see similar issues?  And if not, 
> could you please walk me through your process for testing these patches on 
> rv64, so I can reproduce it here?
>

I'v tried the command line above and got similar issues with probability.
unwind_frame_kernel can not stop unwind when fp is a quite large
value(like 0x70aac93ff0eff584) which can pass the simple stack check.
        if (kstack_end((void *)frame->fp))
                return -EPERM;
        if (frame->fp & 0x3 || frame->fp < TASK_SIZE)
                return -EPERM;
handle_exception from arch/riscv/kernel/entry.S will use s0(fp) as temp
register. The context for this frame is unpredictable. We may add more
strict check in unwind_frame_kernel or keep s0 always 0 in handle_exception
to fix this issue.

Breakpoint 1, unwind_frame_kernel (frame=0xffffffe0000057a0 <rcu_init+118>)
    at arch/riscv/kernel/perf_callchain.c:14
14      {
1: /x *frame = {fp = 0xffffffe000005ee0, ra = 0xffffffe000124c90}
(gdb)
Continuing.

Breakpoint 1, unwind_frame_kernel (frame=0xffffffe0000057a0 <rcu_init+118>)
    at arch/riscv/kernel/perf_callchain.c:14
14      {
1: /x *frame = {fp = 0xffffffe000124c74, ra = 0xffffffe000036cba}
(gdb)
Continuing.

Breakpoint 1, unwind_frame_kernel (frame=0xffffffe0000057a0 <rcu_init+118>)
    at arch/riscv/kernel/perf_callchain.c:14
14      {
1: /x *frame = {fp = 0x70aac57ff0eff584, ra = 0x8082614d64ea740a}
(gdb)

Some time perf record can output perf.data correct. something like:
# perf record -e cpu-clock --call-graph fp ls

perf.data
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.012 MB perf.data (102 samples) ]
# 
# perf report
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 102  of event 'cpu-clock'
# Event count (approx.): 25500000
#
# Children      Self  Command  Shared Object      Symbol                           
# ........  ........  .......  .................  .................................
#
    30.39%     0.00%  ls       [kernel.kallsyms]  [k] ret_from_exception
            |
            ---ret_from_exception
               |          
               |--16.67%--do_page_fault
               |          handle_mm_fault
               |          __handle_mm_fault
               |          |          
               |          |--9.80%--filemap_map_pages
               |          |          |          
               |          |          |--3.92%--alloc_set_pte
               |          |          |          page_add_file_rmap
               |          |          |          
               |          |           --3.92%--filemap_map_pages
               |          |          
               |           --0.98%--__do_fault
               |          
               |--8.82%--schedule
               |          __sched_text_start
               |          finish_task_switch
               |          
                --4.90%--__kprobes_text_start
                          irq_exit
                          irq_exit

    28.43%     0.00%  ls       [kernel.kallsyms]  [k] ret_from_syscall
            |
            ---ret_from_syscall
               |          
               |--15.69%--__se_sys_execve
               |          __do_execve_file
               |          search_binary_handler.part.7

I previous tested these patch with a program(callchain_test.c) mostly
running in userspace, so I didn't got this issues.

Thanks,
Mao Han
Mao Han Aug. 19, 2019, 10:56 a.m. UTC | #4
On Mon, Aug 19, 2019 at 04:18:01PM +0800, Mao Han wrote:
> Hi Paul,
> On Fri, Aug 16, 2019 at 10:14:01AM -0700, Paul Walmsley wrote:
> > Hello Mao Han,
> > 
> > On Fri, 17 May 2019, Mao Han wrote:
> > 
> > > This patch set add perf callchain(FP/DWARF) support for RISC-V.
> > > It comes from the csky version callchain support with some
> > > slight modifications. The patchset base on Linux 5.1.
> > > 
> > > CC: Palmer Dabbelt <palmer@sifive.com>
> > > CC: linux-riscv <linux-riscv@lists.infradead.org>
> > > CC: Christoph Hellwig <hch@lst.de>
> > > CC: Guo Ren <guoren@kernel.org>
> > 
> > I tried these patches on v5.3-rc4, both on the HiFive Unleashed board 
> > with a Debian-based rootfs and QEMU rv64 with a Fedora-based rootfs.  For 
> > QEMU, I used defconfig, and for the HiFive Unleashed, I added a few more 
> > Kconfig directives; and on both, I enabled CONFIG_PERF_EVENTS.  I built 
> > the perf tools from the kernel tree.
> > 
> > Upon running "/root/bin/perf record -e cpu-clock --call-graph fp 
> > /bin/ls", I see the backtraces below.  The first is on the HiFive 
> > Unleashed, the second is on QEMU.  
> > 
> > Could you take a look and tell me if you see similar issues?  And if not, 
> > could you please walk me through your process for testing these patches on 
> > rv64, so I can reproduce it here?
> >
> 
> I'v tried the command line above and got similar issues with probability.
> unwind_frame_kernel can not stop unwind when fp is a quite large
> value(like 0x70aac93ff0eff584) which can pass the simple stack check.
>         if (kstack_end((void *)frame->fp))
>                 return -EPERM;
>         if (frame->fp & 0x3 || frame->fp < TASK_SIZE)
>                 return -EPERM;
> handle_exception from arch/riscv/kernel/entry.S will use s0(fp) as temp
> register. The context for this frame is unpredictable. We may add more
> strict check in unwind_frame_kernel or keep s0 always 0 in handle_exception
> to fix this issue.
> 

perf record -e cpu-clock --call-graph fp /bin/ls seems can work stably
with this change applied.
diff --git a/arch/riscv/kernel/perf_callchain.c b/arch/riscv/kernel/perf_callchain.c
index 8b57903..dd27c67 100644
--- a/arch/riscv/kernel/perf_callchain.c
+++ b/arch/riscv/kernel/perf_callchain.c
@@ -16,6 +16,8 @@ static int unwind_frame_kernel(struct stackframe *frame)
                return -EPERM;
        if (frame->fp & 0x3 || frame->fp < TASK_SIZE)
                return -EPERM;
+        if (frame->fp < CONFIG_PAGE_OFFSET)
+                return -EPERM;
 
        *frame = *((struct stackframe *)frame->fp - 1);
        if (__kernel_text_address(frame->ra)) {


PS: I got some compile error while compiling glibc 2.30 with linux
v5.3-rc4 header. vfork.S include linux/sched.h(./include/uapi/linux/sched.h)
which has a struct clone_args inside, added by
7f192e3cd316ba58c88dfa26796cf77789dd9872.
Paul Walmsley Aug. 24, 2019, 2:12 a.m. UTC | #5
On Mon, 19 Aug 2019, Mao Han wrote:

> PS: I got some compile error while compiling glibc 2.30 with linux
> v5.3-rc4 header. vfork.S include linux/sched.h(./include/uapi/linux/sched.h)
> which has a struct clone_args inside, added by
> 7f192e3cd316ba58c88dfa26796cf77789dd9872.

Noticed that also.  Probably the sched.h uapi kernel header file needs an 
"#ifndef __ASSEMBLY__" around the struct clone_args...


- Paul