Re: [PATCH 05/12] perf tools: Read also the end of the kernel

Arnaldo Carvalho de Melo
2019-05-24T18:15:16Z

Em Wed, May 08, 2019 at 03:20:03PM +0200, Jiri Olsa escreveu:
> We mark the end of kernel based on the first module,
> but that could cover some bpf program maps. Reading
> _etext symbol if it's present to get precise kernel
> map end.

Investigating... Have you run 'perf test' before hitting the send
button? :-)

- Arnaldo

[root@quaco c]# perf test 1
1: vmlinux symtab matches kallsyms : FAILED!
[root@quaco c]# perf test -v 1
1: vmlinux symtab matches kallsyms :
--- start ---
test child forked, pid 17488
Looking at the vmlinux_path (8 entries long)
Using /lib/modules/5.2.0-rc1+/build/vmlinux for symbols
WARN: 0xffffffff8c001000: diff name v: hypercall_page k: xen_hypercall_set_trap_table
WARN: 0xffffffff8c0275c0: diff name v: __ia32_sys_rt_sigreturn k: __x64_sys_rt_sigreturn
WARN: 0xffffffff8c06ac31: diff name v: end_irq_irq_disable k: start_irq_irq_enable
WARN: 0xffffffff8c06ac32: diff name v: end_irq_irq_enable k: start_irq_restore_fl
WARN: 0xffffffff8c06ac34: diff name v: end_irq_restore_fl k: start_irq_save_fl
WARN: 0xffffffff8c06ac36: diff name v: end_irq_save_fl k: start_mmu_read_cr2
WARN: 0xffffffff8c06ac3c: diff name v: end_mmu_read_cr3 k: start_mmu_write_cr3
WARN: 0xffffffff8c06ac3f: diff name v: end_mmu_write_cr3 k: start_cpu_wbinvd
WARN: 0xffffffff8c06ac41: diff name v: end_cpu_wbinvd k: start_cpu_usergs_sysret64
WARN: 0xffffffff8c06ac47: diff name v: end_cpu_usergs_sysret64 k: start_cpu_swapgs
WARN: 0xffffffff8c06ac4a: diff name v: end_cpu_swapgs k: start__mov64
WARN: 0xffffffff8c0814b0: diff end addr for aesni_gcm_dec v: 0xffffffff8c083606 k: 0xffffffff8c0817c7
WARN: 0xffffffff8c083610: diff end addr for aesni_gcm_enc v: 0xffffffff8c0856f2 k: 0xffffffff8c083927
WARN: 0xffffffff8c085c00: diff end addr for aesni_gcm_enc_update v: 0xffffffff8c087556 k: 0xffffffff8c085c31
WARN: 0xffffffff8c087560: diff end addr for aesni_gcm_dec_update v: 0xffffffff8c088f2a k: 0xffffffff8c087591
WARN: 0xffffffff8c08b7c0: diff end addr for aesni_gcm_enc_update_avx_gen2 v: 0xffffffff8c09b13c k: 0xffffffff8c08b818
WARN: 0xffffffff8c08fac1: diff name v: _initial_blocks_done2259 k: _initial_blocks_encrypted15
WARN: 0xffffffff8c094943: diff name v: _initial_blocks_done4447 k: _initial_blocks_encrypted2497
WARN: 0xffffffff8c09a023: diff name v: _initial_blocks_done7187 k: _initial_blocks_encrypted4649
WARN: 0xffffffff8c09b140: diff end addr for aesni_gcm_dec_update_avx_gen2 v: 0xffffffff8c0ab05f k: 0xffffffff8c09b198
WARN: 0xffffffff8c09f5b6: diff name v: _initial_blocks_done9706 k: _initial_blocks_encrypted7462
WARN: 0xffffffff8c0a4619: diff name v: _initial_blocks_done11894 k: _initial_blocks_encrypted9944
WARN: 0xffffffff8c0a9eda: diff name v: _initial_blocks_done14634 k: _initial_blocks_encrypted12096
WARN: 0xffffffff8c0abcd0: diff end addr for aesni_gcm_enc_update_avx_gen4 v: 0xffffffff8c0ba4a6 k: 0xffffffff8c0abd28
WARN: 0xffffffff8c0afaa5: diff name v: _initial_blocks_done17291 k: _initial_blocks_encrypted15047
WARN: 0xffffffff8c0b4345: diff name v: _initial_blocks_done19479 k: _initial_blocks_encrypted17529
WARN: 0xffffffff8c0b9443: diff name v: _initial_blocks_done22219 k: _initial_blocks_encrypted19681
WARN: 0xffffffff8c0ba4b0: diff end addr for aesni_gcm_dec_update_avx_gen4 v: 0xffffffff8c0c9229 k: 0xffffffff8c0ba508
WARN: 0xffffffff8c0be3fa: diff name v: _initial_blocks_done24738 k: _initial_blocks_encrypted22494
WARN: 0xffffffff8c0c2e7b: diff name v: _initial_blocks_done26926 k: _initial_blocks_encrypted24976
WARN: 0xffffffff8c0c815a: diff name v: _initial_blocks_done29666 k: _initial_blocks_encrypted27128
WARN: 0xffffffff8c0dc2b0: diff name v: __ia32_sys_fork k: __x64_sys_fork
WARN: 0xffffffff8c0dc2d0: diff name v: __ia32_sys_vfork k: __x64_sys_vfork
WARN: 0xffffffff8c0e9eb0: diff name v: __ia32_sys_restart_syscall k: __x64_sys_restart_syscall
WARN: 0xffffffff8c0e9f30: diff name v: __ia32_sys_sgetmask k: __x64_sys_sgetmask
WARN: 0xffffffff8c0ea4b0: diff name v: __ia32_sys_pause k: __x64_sys_pause
WARN: 0xffffffff8c0f1610: diff name v: __ia32_sys_gettid k: __x64_sys_gettid
WARN: 0xffffffff8c0f1630: diff name v: __ia32_sys_getpid k: __x64_sys_getpid
WARN: 0xffffffff8c0f1650: diff name v: __ia32_sys_getppid k: __x64_sys_getppid
WARN: 0xffffffff8c0f1980: diff name v: __ia32_sys_getuid k: __x64_sys_getuid
WARN: 0xffffffff8c0f19b0: diff name v: __ia32_sys_geteuid k: __x64_sys_geteuid
WARN: 0xffffffff8c0f1b30: diff name v: __ia32_sys_getgid k: __x64_sys_getgid
WARN: 0xffffffff8c0f1b60: diff name v: __ia32_sys_getegid k: __x64_sys_getegid
WARN: 0xffffffff8c0f2130: diff name v: __ia32_sys_getpgrp k: __x64_sys_getpgrp
WARN: 0xffffffff8c0f52f0: diff name v: __ia32_sys_setsid k: __x64_sys_setsid
WARN: 0xffffffff8c1016d0: diff name v: sys_ni_syscall k: __x64_sys_vm86old
WARN: 0xffffffff8c10b400: diff name v: __ia32_sys_sched_yield k: __x64_sys_sched_yield
WARN: 0xffffffff8c1775a0: diff name v: __ia32_sys_getuid16 k: __x64_sys_getuid16
WARN: 0xffffffff8c1775f0: diff name v: __ia32_sys_geteuid16 k: __x64_sys_geteuid16
WARN: 0xffffffff8c177640: diff name v: __ia32_sys_getgid16 k: __x64_sys_getgid16
WARN: 0xffffffff8c177690: diff name v: __ia32_sys_getegid16 k: __x64_sys_getegid16
WARN: 0xffffffff8c1fa600: diff name v: mark_reg_not_init.part.48 k: mark_reg_unknown.part.51
WARN: 0xffffffff8c21c1f0: diff name v: perf_pmu_cancel_txn.part.104 k: perf_pmu_commit_txn.part.105
WARN: 0xffffffff8c23cad0: diff name v: __probe_kernel_read k: probe_kernel_read
WARN: 0xffffffff8c23cb50: diff name v: __probe_kernel_write k: probe_kernel_write
WARN: 0xffffffff8c277720: diff name v: __ia32_sys_munlockall k: __x64_sys_munlockall
WARN: 0xffffffff8c2e9a70: diff name v: __ia32_sys_vhangup k: __x64_sys_vhangup
WARN: 0xffffffff8c325d30: diff name v: __ia32_sys_sync k: __x64_sys_sync
WARN: 0xffffffff8c33c310: diff name v: __ia32_sys_inotify_init k: __x64_sys_inotify_init
WARN: 0xffffffff8c42be70: diff name v: selinux_msg_queue_msgctl.part.37 k: selinux_shm_shmctl.part.36
WARN: 0xffffffff8c4574c0: diff name v: _rsa_dec.isra.2 k: _rsa_enc.isra.3
WARN: 0xffffffff8c4c84e0: diff name v: __crc32c_le_base k: __crc32c_le
WARN: 0xffffffff8c4c8630: diff name v: crc32_le_base k: crc32_le
WARN: 0xffffffff8c516041: diff name v: quirk_disable_msi.part.30 k: quirk_msi_ht_cap.part.43
WARN: 0xffffffff8c596c80: diff name v: clkdev_hw_create k: __clk_register_clkdev
WARN: 0xffffffff8c844430: diff name v: phys_switch_id_show.part.17 k: speed_show.part.22
WARN: 0xffffffff8c8578f0: diff name v: devlink_fmsg_arr_pair_nest_end.part.56 k: devlink_fmsg_u8_pair_put.part.60
WARN: 0xffffffff8c9961d0: diff name v: __memcpy k: memcpy
WARN: 0xffffffff8c996370: diff name v: __memmove k: memmove
WARN: 0xffffffff8c996510: diff name v: __memset k: memset
WARN: 0xffffffff8c996b90: diff end addr for csum_partial_copy_generic v: 0xffffffff8c996cf9 k: 0xffffffff8c999590
WARN: 0xffffffff8c9a6e50: diff name v: default_idle k: __cpuidle_text_start
WARN: 0xffffffff8ca00000: diff name v: native_usergs_sysret64 k: __entry_text_start
WARN: 0xffffffff8ca00a3b: diff name v: restore_regs_and_return_to_kernel k: retint_kernel
ERR : 0xffffffff8cc00e41: __indirect_thunk_end not on kallsyms
WARN: Maps only in vmlinux:
b000000-b02c000 1c00000 [kernel].data..percpu
ffffffff8cc00e44-ffffffff8cc01044 e00e44 [kernel].notes
ffffffff8ce00000-ffffffff8d1c9372 1000000 [kernel].rodata
ffffffff8d1cbfb0-ffffffff8d1cc028 13cbfb0 [kernel].tracedata
ffffffff8d1e04d0-ffffffff8d2123a0 13e04d0 [kernel]__ksymtab_strings
ffffffff8d2123a0-ffffffff8d2125d0 14123a0 [kernel]__init_rodata
ffffffff8d2125d0-ffffffff8d215bb8 14125d0 [kernel]__param
ffffffff8d215bb8-ffffffff8d216000 1415bb8 [kernel]__modver
ffffffff8d400000-ffffffff8d5679c0 1600000 [kernel].data
ffffffff8d933000-ffffffff8d934000 1b33000 [kernel].vvar
ffffffff8d960000-ffffffff8d9dcb2f 1d60000 [kernel].init.text
ffffffff8d9de000-ffffffff8db46590 1dde000 [kernel].init.data
ffffffff8db46590-ffffffff8db465b0 1f46590 [kernel].x86_cpu_dev.init
ffffffff8db5ded0-ffffffff8db5df98 1f5ded0 [kernel].iommu_table
ffffffff8db5df98-ffffffff8db5dfd8 1f5df98 [kernel].apicdrivers
ffffffff8db5dfd8-ffffffff8db5f85e 1f5dfd8 [kernel].exit.text
ffffffff8db69000-ffffffff8db6a000 1f69000 [kernel].data_nosave
ffffffff8db6a000-ffffffff8e000000 1f6a000 [kernel].bss
test child finished with -1
---- end ----
vmlinux symtab matches kallsyms: FAILED!
[root@quaco c]#

[acme@quaco perf]$ git bisect good
7d98e1a73bd7dae6cb321ec8b0b97b9fed7c0e1b is the first bad commit
commit 7d98e1a73bd7dae6cb321ec8b0b97b9fed7c0e1b
Author: Jiri Olsa <jolsa@kernel.org>
Date: Wed May 8 15:20:03 2019 +0200

perf machine: Read also the end of the kernel

We mark the end of kernel based on the first module, but that could
cover some bpf program maps. Reading _etext symbol if it's present to
get precise kernel map end.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stanislav Fomichev <sdf@google.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Link: http://lkml.kernel.org/r/20190508132010.14512-6-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

:040000 040000 4ca5fa4c6f15fd8cf9a0eee870efbd01e9fe309d 8311b30f94e9cf9a863dc9619b0499863f64960e M tools
[acme@quaco perf]$

> Link: http://lkml.kernel.org/n/tip-ynut991ttyyhvo1sbhlm4c42@git.kernel.org
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---
> tools/perf/util/machine.c | 27 ++++++++++++++++++---------
> 1 file changed, 18 insertions(+), 9 deletions(-)
>
> diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
> index 3c520baa198c..ad0205fbb506 100644
> --- a/tools/perf/util/machine.c
> +++ b/tools/perf/util/machine.c
> @@ -924,7 +924,8 @@ const char *ref_reloc_sym_names[] = {"_text", "_stext", NULL};
> * symbol_name if it's not that important.
> */
> static int machine__get_running_kernel_start(struct machine *machine,
> - const char **symbol_name, u64 *start)
> + const char **symbol_name,
> + u64 *start, u64 *end)
> {
> char filename[PATH_MAX];
> int i, err = -1;
> @@ -949,6 +950,11 @@ static int machine__get_running_kernel_start(struct machine *machine,
> *symbol_name = name;
>
> *start = addr;
> +
> + err = kallsyms__get_function_start(filename, "_etext", &addr);
> + if (!err)
> + *end = addr;
> +
> return 0;
> }
>
> @@ -1440,7 +1446,7 @@ int machine__create_kernel_maps(struct machine *machine)
> struct dso *kernel = machine__get_kernel(machine);
> const char *name = NULL;
> struct map *map;
> - u64 addr = 0;
> + u64 start = 0, end = ~0ULL;
> int ret;
>
> if (kernel == NULL)
> @@ -1459,9 +1465,9 @@ int machine__create_kernel_maps(struct machine *machine)
> "continuing anyway...\n", machine->pid);
> }
>
> - if (!machine__get_running_kernel_start(machine, &name, &addr)) {
> + if (!machine__get_running_kernel_start(machine, &name, &start, &end)) {
> if (name &&
> - map__set_kallsyms_ref_reloc_sym(machine->vmlinux_map, name, addr)) {
> + map__set_kallsyms_ref_reloc_sym(machine->vmlinux_map, name, start)) {
> machine__destroy_kernel_maps(machine);
> ret = -1;
> goto out_put;
> @@ -1471,16 +1477,19 @@ int machine__create_kernel_maps(struct machine *machine)
> * we have a real start address now, so re-order the kmaps
> * assume it's the last in the kmaps
> */
> - machine__update_kernel_mmap(machine, addr, ~0ULL);
> + machine__update_kernel_mmap(machine, start, end);
> }
>
> if (machine__create_extra_kernel_maps(machine, kernel))
> pr_debug("Problems creating extra kernel maps, continuing anyway...\n");
>
> - /* update end address of the kernel map using adjacent module address */
> - map = map__next(machine__kernel_map(machine));
> - if (map)
> - machine__set_kernel_mmap(machine, addr, map->start);
> + if (end == ~0ULL) {
> + /* update end address of the kernel map using adjacent module address */
> + map = map__next(machine__kernel_map(machine));
> + if (map)
> + machine__set_kernel_mmap(machine, start, map->start);
> + }
> +
> out_put:
> dso__put(kernel);
> return ret;
> --
> 2.20.1

--

- Arnaldo