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Date:   Tue, 24 Aug 2021 11:38:49 +0200
From:   Jiri Olsa <jolsa@redhat.com>
To:     Adrian Hunter <adrian.hunter@intel.com>
Cc:     Arnaldo Carvalho de Melo <acme@kernel.org>,
        linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
        Peter Zijlstra <peterz@infradead.org>
Subject: Re: intel_pt crash on alderlake
Message-ID: <YSS+KbILtcwomsN4@krava>
References: <YSPWCienSPEcvIbU@krava>
 <7e214d48-ff09-6fe0-f624-d82260ada786@intel.com>
 <YSPlmP4quB7N+qQE@krava>
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On Mon, Aug 23, 2021 at 08:14:48PM +0200, Jiri Olsa wrote:
> On Mon, Aug 23, 2021 at 08:53:32PM +0300, Adrian Hunter wrote:
> > On 23/08/21 8:08 pm, Jiri Olsa wrote:
> > > hi,
> > > should intel_pt work on alderlake? I'm getting strange crash:
> > > (cpuinfo and uname below)
> > >=20
> > > 	[root@intel-alderlake-m-02 perf]# ./perf record -e 'intel_pt//' --ov=
erwrite=20
> >=20
> > The segfault is related --overwrite not Alderlake.
>=20
> ok, now I see that failing also on other server.. was too fast sry

any idea of quick fix before I dive in? ;-)
seems like permissions changed on the first mmap page for some reason

thanks,
jirka

>=20
> >=20
> > Although I am not sure --overwrite make sense for Intel PT since we hav=
e snapshot mode i.e. --snapshot
>=20
> it's for kdump to get the inte_pt data after crash
>=20
> thanks,
> jirka
>=20
> >=20
> > > 	perf: Segmentation fault
> > > 	Obtained 16 stack frames.
> > > 	./perf() [0x53b6eb]
> > > 	./perf() [0x53b7cb]
> > > 	./perf() [0x429b30]
> > > 	/lib64/libc.so.6(+0x37400) [0x7f7b144db400]
> > > 	./perf() [0x5a6fc8]
> > > 	./perf() [0x505caa]
> > > 	./perf() [0x4f39ca]
> > > 	./perf() [0x646879]
> > > 	./perf() [0x646b57]
> > > 	./perf() [0x646da0]
> > > 	./perf() [0x4f3eec]
> > > 	./perf() [0x42a533]
> > > 	./perf() [0x42a644]
> > > 	./perf() [0x42aa72]
> > > 	./perf() [0x42c915]
> > > 	./perf() [0x42ecc3]
> > > 	Segmentation fault (core dumped)
> > >=20
> > >=20
> > > 	[root@intel-alderlake-m-02 perf]# gdb ./perf
> > > 	GNU gdb (GDB) Red Hat Enterprise Linux 8.2-15.el8
> > > 	Copyright (C) 2018 Free Software Foundation, Inc.
> > > 	License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/=
gpl.html>
> > > 	This is free software: you are free to change and redistribute it.
> > > 	There is NO WARRANTY, to the extent permitted by law.
> > > 	Type "show copying" and "show warranty" for details.
> > > 	This GDB was configured as "x86_64-redhat-linux-gnu".
> > > 	Type "show configuration" for configuration details.
> > > 	For bug reporting instructions, please see:
> > > 	<http://www.gnu.org/software/gdb/bugs/>.
> > > 	Find the GDB manual and other documentation resources online at:
> > > 	    <http://www.gnu.org/software/gdb/documentation/>.
> > >=20
> > > 	For help, type "help".
> > > 	Type "apropos word" to search for commands related to "word"...
> > > 	Reading symbols from ./perf...done.
> > > 	(gdb) r record -e 'intel_pt//' --overwrite
> > > 	Starting program: /root/linux/tools/perf/perf record -e 'intel_pt//'=
 --overwrite
> > > 	[Thread debugging using libthread_db enabled]
> > > 	Using host libthread_db library "/lib64/libthread_db.so.1".
> > >=20
> > > 	Program received signal SIGSEGV, Segmentation fault.
> > > 	0x00000000005a6fc8 in auxtrace_mmap__mmap (mm=3D0x7ffff7e9c060, mp=
=3D0x7fffffff7588, userpg=3D0x7ffff7e0b000, fd=3D5) at util/auxtrace.c:133
> > > 	133             pc->aux_offset =3D mp->offset;
> > > 	Missing separate debuginfos, use: yum debuginfo-install brotli-1.0.6=
-3.el8.x86_64 bzip2-libs-1.0.6-26.el8.x86_64 cyrus-sasl-lib-2.1.27-5.el8.x8=
6_64 elfutils-debuginfod-client-0.185-1.el8.x86_64 elfutils-libelf-0.185-1.=
el8.x86_64 elfutils-libs-0.185-1.el8.x86_64 glib2-2.56.4-156.el8.x86_64 gmp=
-6.1.2-10.el8.x86_64 gnutls-3.6.16-4.el8.x86_64 keyutils-libs-1.5.10-9.el8.=
x86_64 libbabeltrace-1.5.4-3.el8.x86_64 libbpf-0.3.0-1.el8.x86_64 libcap-2.=
26-4.el8.x86_64 libcom_err-1.45.6-2.el8.x86_64 libcurl-7.61.1-18.el8.x86_64=
 libffi-3.1-22.el8.x86_64 libidn2-2.2.0-1.el8.x86_64 libpsl-0.20.2-6.el8.x8=
6_64 libselinux-2.9-5.el8.x86_64 libssh-0.9.4-3.el8.x86_64 libtasn1-4.13-3.=
el8.x86_64 libunistring-0.9.9-3.el8.x86_64 libuuid-2.32.1-28.el8.x86_64 lib=
xcrypt-4.1.1-6.el8.x86_64 libzstd-1.4.4-1.el8.x86_64 numactl-libs-2.0.12-13=
=2Eel8.x86_64 openldap-2.4.46-17.el8.x86_64 openssl-libs-1.1.1k-4.el8.x86_6=
4 p11-kit-0.23.22-1.el8.x86_64 pcre-8.42-6.el8.x86_64 pcre2-10.32-2.el8.x86=
_64 perl-libs-5.26.3-420.el8.x86_64 popt-1.18-1.el8.x86_64 slang-2.3.2-3.el=
8.x86_64 xz-libs-5.2.4-3.el8.x86_64
> > > 	(gdb) bt
> > > 	#0  0x00000000005a6fc8 in auxtrace_mmap__mmap (mm=3D0x7ffff7e9c060, =
mp=3D0x7fffffff7588, userpg=3D0x7ffff7e0b000, fd=3D5) at util/auxtrace.c:133
> > > 	#1  0x0000000000505caa in mmap__mmap (map=3D0x7ffff7e8c010, mp=3D0x7=
fffffff7570, fd=3D5, cpu=3D0) at util/mmap.c:306
> > > 	#2  0x00000000004f39ca in perf_evlist__mmap_cb_mmap (_map=3D0x7ffff7=
e8c010, _mp=3D0x7fffffff7570, output=3D5, cpu=3D0) at util/evlist.c:807
> > > 	#3  0x0000000000646879 in mmap_per_evsel (evlist=3D0xf1c7d0, ops=3D0=
x7fffffff7550, idx=3D0, mp=3D0x7fffffff7570, cpu_idx=3D0, thread=3D0, _outp=
ut=3D0x7fffffff7480, _output_overwrite=3D0x7fffffff7484) at evlist.c:477
> > > 	#4  0x0000000000646b57 in mmap_per_cpu (evlist=3D0xf1c7d0, ops=3D0x7=
fffffff7550, mp=3D0x7fffffff7570) at evlist.c:550
> > > 	#5  0x0000000000646da0 in perf_evlist__mmap_ops (evlist=3D0xf1c7d0, =
ops=3D0x7fffffff7550, mp=3D0x7fffffff7570) at evlist.c:602
> > > 	#6  0x00000000004f3eec in evlist__mmap_ex (evlist=3D0xf1c7d0, pages=
=3D4294967295, auxtrace_pages=3D1024, auxtrace_overwrite=3Dfalse, nr_cblock=
s=3D0, affinity=3D0, flush=3D1, comp_level=3D0) at util/evlist.c:959
> > > 	#7  0x000000000042a533 in record__mmap_evlist (rec=3D0xc8b580 <recor=
d>, evlist=3D0xf1c7d0) at builtin-record.c:854
> > > 	#8  0x000000000042a644 in record__mmap (rec=3D0xc8b580 <record>) at =
builtin-record.c:881
> > > 	#9  0x000000000042aa72 in record__open (rec=3D0xc8b580 <record>) at =
builtin-record.c:963
> > > 	#10 0x000000000042c915 in __cmd_record (rec=3D0xc8b580 <record>, arg=
c=3D0, argv=3D0x7fffffffddf0) at builtin-record.c:1717
> > > 	#11 0x000000000042ecc3 in cmd_record (argc=3D0, argv=3D0x7fffffffddf=
0) at builtin-record.c:2897
> > > 	#12 0x00000000004d7143 in run_builtin (p=3D0xca33d8 <commands+216>, =
argc=3D4, argv=3D0x7fffffffddf0) at perf.c:313
> > > 	#13 0x00000000004d73b0 in handle_internal_command (argc=3D4, argv=3D=
0x7fffffffddf0) at perf.c:365
> > > 	#14 0x00000000004d74f7 in run_argv (argcp=3D0x7fffffffdc4c, argv=3D0=
x7fffffffdc40) at perf.c:409
> > > 	#15 0x00000000004d78c3 in main (argc=3D4, argv=3D0x7fffffffddf0) at =
perf.c:539
> > > 	(gdb) p *pc
> > > 	$1 =3D {version =3D 0, compat_version =3D 0, lock =3D 2, index =3D 0=
, offset =3D 0, time_enabled =3D 0, time_running =3D 0, {capabilities =3D 2=
6, {cap_bit0 =3D 0, cap_bit0_is_deprecated =3D 1, cap_user_rdpmc =3D 0, cap=
_user_time =3D 1,=20
> > > 	      cap_user_time_zero =3D 1, cap_user_time_short =3D 0, cap_____r=
es =3D 0}}, pmc_width =3D 48, time_shift =3D 31, time_mult =3D 2663050159, =
time_offset =3D 18446743875728538161, time_zero =3D 18446743981699475147,=
=20
> > > 	  size =3D 96, __reserved_1 =3D 0, time_cycles =3D 0, time_mask =3D =
0, __reserved =3D '\000' <repeats 927 times>, data_head =3D 0, data_tail =
=3D 0, data_offset =3D 4096, data_size =3D 524288, aux_head =3D 0, aux_tail=
 =3D 0,=20
> > > 	  aux_offset =3D 0, aux_size =3D 0}
> > > 	(gdb) p *mp
> > > 	$2 =3D {mask =3D 4194303, offset =3D 528384, len =3D 4194304, prot =
=3D 3, idx =3D 0, tid =3D -1, cpu =3D 0}
> > > 	(gdb)=20
> > >=20
> > >=20
> > > any idea? thanks,
> > > jirka
> > >=20
> > >=20
> > > ----
> > > [jolsa@krava linus-pure]$ cat /proc/cpuinfo=20
> > > processor       : 0
> > > vendor_id       : GenuineIntel
> > > cpu family      : 6
> > > model           : 142
> > > model name      : Intel(R) Core(TM) i7-8650U CPU @ 1.90GHz
> > > stepping        : 10
> > > microcode       : 0xea
> > > cpu MHz         : 2100.000
> > > cache size      : 8192 KB
> > > physical id     : 0
> > > siblings        : 8
> > > core id         : 0
> > > cpu cores       : 4
> > > apicid          : 0
> > > initial apicid  : 0
> > > fpu             : yes
> > > fpu_exception   : yes
> > > cpuid level     : 22
> > > wp              : yes
> > > flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pg=
e mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscal=
l nx pdpe1gb rdtscp lm constant_tsc art arch_perfmon pebs bts rep_good nopl=
 xtopology nonstop_tsc cpuid aperfmperf pni pclmulqdq dtes64 monitor ds_cpl=
 vmx smx est tm2 ssse3 sdbg fma cx16 xtpr pdcm pcid sse4_1 sse4_2 x2apic mo=
vbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm abm 3dnowpr=
efetch cpuid_fault epb invpcid_single pti ssbd ibrs ibpb stibp tpr_shadow v=
nmi flexpriority ept vpid ept_ad fsgsbase tsc_adjust bmi1 hle avx2 smep bmi=
2 erms invpcid rtm mpx rdseed adx smap clflushopt intel_pt xsaveopt xsavec =
xgetbv1 xsaves dtherm ida arat pln pts hwp hwp_notify hwp_act_window hwp_ep=
p md_clear flush_l1d
> > > vmx flags       : vnmi preemption_timer invvpid ept_x_only ept_ad ept=
_1gb flexpriority tsc_offset vtpr mtf vapic ept vpid unrestricted_guest ple=
 shadow_vmcs pml ept_mode_based_exec
> > > bugs            : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypas=
s l1tf mds swapgs taa itlb_multihit srbds
> > > bogomips        : 4199.88
> > > clflush size    : 64
> > > cache_alignment : 64
> > > address sizes   : 39 bits physical, 48 bits virtual
> > > power management:
> > >=20
> > > [root@intel-alderlake-m-02 linux]# uname -a
> > > Linux intel-alderlake-m-02.ml3.eng.bos.redhat.com 5.14.0-rc6+ #1 SMP =
Fri Aug 20 09:27:39 EDT 2021 x86_64 x86_64 x86_64 GNU/Linux
> > >=20
> >=20