tcon can not be null in SMB2_tcon function so the check
is not relevant and removing it makes Coverity happy.
Acked-by: NRonnie Sahlberg <lsahlber@redhat.com>
Addresses-Coverity: 13250131 ("Dereference before null check")
Signed-off-by: NSteve French <stfrench@microsoft.com>

Add SPDX license identifier and replace license boilerplate.
Corrects various checkpatch errors with the older format for
noting the LGPL license.
Signed-off-by: NSteve French <stfrench@microsoft.com>

convert list_for_each() to list_for_each_entry() where
applicable.
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NBaokun Li <libaokun1@huawei.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

convert list_for_each() to list_for_each_entry() where
applicable.
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NBaokun Li <libaokun1@huawei.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

In posix_info_parse() we call posix_info_sid_size twice for each of the owner and the group
sid. The first time to check that it is valid, i.e. >= 0 and the second time
to just pass it in as a length to memcpy().
As this is a pure function we know that it can not be negative the second time and this
is technically a false warning in coverity.
However, as it is a pure function we are just wasting cycles by calling it a second time.
Record the length from the first time we call it and save some cycles as well as make
Coverity happy.

Addresses-Coverity-ID: 1491379 ("Argument can not be negative")
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

According to the investigation performed by Jacob Shivers at Red Hat,
cifs_lookup and cifs_readdir leak EAGAIN when the user session is
deleted on the server. Fix this issue by implementing a retry with
limits, as is implemented in cifs_revalidate_dentry_attr.

Reproducer based on the work by Jacob Shivers:

  ~~~
  $ cat readdir-cifs-test.sh
  #!/bin/bash

  # Install and configure powershell and sshd on the windows
  #  server as descibed in
  # https://docs.microsoft.com/en-us/windows-server/administration/openssh/openssh_overview
  # This script uses expect(1)

  USER=dude
  SERVER=192.168.0.2
  RPATH=root
  PASS='password'

  function debug_funcs {
  	for line in $@ ; do
  		echo "func $line +p" > /sys/kernel/debug/dynamic_debug/control
  	done
  }

  function setup {
  	echo 1 > /proc/fs/cifs/cifsFYI
  	debug_funcs wait_for_compound_request \
                smb2_query_dir_first cifs_readdir \
                compound_send_recv cifs_reconnect_tcon \
                generic_ip_connect cifs_reconnect \
                smb2_reconnect_server smb2_reconnect \
                cifs_readv_from_socket cifs_readv_receive
  	tcpdump -i eth0 -w cifs.pcap host 192.168.2.182 & sleep 5
  	dmesg -C
  }

  function test_call {
  	if [[ $1 == 1 ]] ; then
  		tracer="strace -tt -f -s 4096 -o trace-$(date -Iseconds).txt"
  	fi
        # Change the command here to anything appropriate
  	$tracer ls $2 > /dev/null
  	res=$?
  	if [[ $1 == 1 ]] ; then
  		if [[ $res == 0 ]] ; then
  			1>&2 echo success
  		else
  			1>&2 echo "failure ($res)"
  		fi
  	fi
  }

  mountpoint /mnt > /dev/null || mount -t cifs -o username=$USER,pass=$PASS //$SERVER/$RPATH /mnt

  test_call 0 /mnt/

  /usr/bin/expect << EOF
  	set timeout 60

  	spawn ssh $USER@$SERVER

  	expect "yes/no" {
  		send "yes\r"
  		expect "*?assword" { send "$PASS\r" }
  	} "*?assword" { send "$PASS\r" }

  	expect ">" { send "powershell close-smbsession -force\r" }
  	expect ">" { send "exit\r" }
  	expect eof
  EOF

  sysctl -w vm.drop_caches=2 > /dev/null
  sysctl -w vm.drop_caches=2 > /dev/null

  setup

  test_call 1 /mnt/
  ~~~
Signed-off-by: NThiago Rafael Becker <trbecker@gmail.com>
Acked-by: NRonnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Interlink is a special type of DFS link that resolves to a different
DFS domain-based namespace.  To determine whether it is an interlink
or not, check if ReferralServers and StorageServers bits are set to 1
and 0 respectively in ReferralHeaderFlags, as specified in MS-DFSC
3.1.5.4.5 Determining Whether a Referral Response is an Interlink.
Signed-off-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Decode negTokenInit with lib/asn1_decoder. For that,
add OIDs in linux/oid_registry.h and a negTokenInit
ASN1 file, "spnego_negtokeninit.asn1".
And define decoder's callback functions, which
are the gssapi_this_mech for checking SPENGO oid and
the neg_token_init_mech_type for getting authentication
mechanisms supported by a server.
Signed-off-by: NHyunchul Lee <hyc.lee@gmail.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Reviewed-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: NSteve French <stfrench@microsoft.com>

When refreshing the DFS cache, keep SMB2 IOCTL calls as much outside
critical sections as possible and avoid read/write starvation when
getting new DFS referrals by using broken or slow connections.
Signed-off-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

CONFIG_CIFS_STATS2 can be very useful since it shows
latencies by command, and allows enabling the slow response
dynamic tracepoint which can be useful to identify
performance problems.

For example:

Total time spent processing by command. Time units are jiffies (1000 per second)
  SMB3 CMD	Number	Total Time	Fastest	Slowest
  --------	------	----------	-------	-------
  0		1	2		2	2
  1		2	6		2	4
  2		0	0		0	0
  3		4	11		2	4
  4		2	16		5	11
  5		4546	34104		2	487
  6		4421	32901		2	487
  7		0	0		0	0
  8		695	2781		2	39
  9		391	1708		2	27
  10		0	0		0	0
  11		4	6		1	2
  12		0	0		0	0
  13		0	0		0	0
  14		3887	17696		0	128
  15		0	0		0	0
  16		1471	9950		1	487
  17		169	2695		9	116
  18		80	381		2	10
  1		2	6		2	4
  2		0	0		0	0
  3		4	11		2	4
  4		2	16		5	11
  5		4546	34104		2	487
  6		4421	32901		2	487
  7		0	0		0	0
  8		695	2781		2	39
  9		391	1708		2	27
  10		0	0		0	0
  11		4	6		1	2
  12		0	0		0	0
  13		0	0		0	0
  14		3887	17696		0	128
  15		0	0		0	0
  16		1471	9950		1	487
  17		169	2695		9	116
  18		80	381		2	10
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Reviewed-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: NSteve French <stfrench@microsoft.com>

When we lookup an smb session based on session id,
we did not up the ref-count for the session. This can
potentially cause issues if the session is freed from under us.
Signed-off-by: NShyam Prasad N <sprasad@microsoft.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Reviewed-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: NSteve French <stfrench@microsoft.com>

It isn't enough to have unshared tcons because multiple DFS mounts can
connect to same target server and failover to different servers, so we
can't use a single tcp server for such cases.

For the simplest solution, use nosharesock option to achieve that.
Signed-off-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

We don't want to refresh the dfs cache in very short intervals, so
setting a minimum interval of 2 minutes is OK.

If it needs to be refreshed immediately, one could have the cache
cleared with

	$ echo 0 > /proc/fs/cifs/dfscache

and then remounting the dfs share.
Signed-off-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Fix cache lookup and hash calculations when handling paths with
different cases.
Signed-off-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Convert all dfs paths to dfs cache's local codepage (@cache_cp) and
avoid mixing them with different charsets.
Signed-off-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

At every mount, keep all sessions alive that were used for chasing the
DFS referrals as long as the dfs mounts are active.

Use those sessions in DFS cache to refresh all active tcons as well as
cached entries.  They will be managed by a list of mount_group
structures that will be indexed by a randomly generated uuid at mount
time, so we can put all the sessions related to specific dfs mounts
and avoid leaking them.
Signed-off-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

@noreq param isn't used anywhere, so just remove it.
Signed-off-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

On session close, the IPC is closed and the server must release all
tcons of the session.  It doesn't matter if we send a ipc close or
not.

Besides, it will make the server to not close durable and resilient
files on session close, as specified in MS-SMB2 3.3.5.6 Receiving an
SMB2 LOGOFF Request.
Signed-off-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>

RHBZ: 1866684

We don't have a real fallocate in the SMB2 protocol so we used to emulate fallocate
by simply switching the file to become non-sparse. But as that could potantially consume
a lot more data than we intended to fallocate (large sparse file and fallocating a thin
slice in the middle) we would only do this IFF the fallocate request was for virtually
the entire file.

This patch improves this and starts allowing us to fallocate smaller chunks of a file by
overwriting the region with 0, for the parts that are unallocated.

The method used is to first query the server for FSCTL_QUERY_ALLOCATED_RANGES to find what
is unallocated in the fallocate range and then to only overwrite-with-zero the unallocated
ranges to fill in the holes.

As overwriting-with-zero is different from just allocating blocks, and potentially much
more expensive, we limit this to only allow fallocate ranges up to 1Mb in size.
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NRonnie Sahlberg <lsahlber@redhat.com>
Acked-by: NAurelien Aptel <aaptel@suse.com>
Acked-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Add description for `cifs_compose_mount_options` to fix the W=1 warnings:

 fs/cifs/cifs_dfs_ref.c:139: warning: Function parameter or
  member 'devname' not described in 'cifs_compose_mount_options'
Signed-off-by: NBaokun Li <libaokun1@huawei.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Reviewed-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: NSteve French <stfrench@microsoft.com>

The variable rc is being initialized with a value that is never read, the
assignment is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Reviewed-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: NSteve French <stfrench@microsoft.com>

The only usage of cifs_genl_ops[] is to assign its address to the ops
field in the genl_family struct, which is a pointer to const. Make it
const to allow the compiler to put it in read-only memory.
Signed-off-by: NRikard Falkeborn <rikard.falkeborn@gmail.com>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Reviewed-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: NSteve French <stfrench@microsoft.com>

is_sysvol_or_netlogon() is never used, so can remove it.
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Reviewed-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: NSteve French <stfrench@microsoft.com>

smb2_find_smb_ses was defined twice in smb2proto.h
Signed-off-by: NSteve French <stfrench@microsoft.com>

Use %pI6 for IPv6 addresses
Signed-off-by: NAurelien Aptel <aaptel@suse.com>
Reviewed-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: NSteve French <stfrench@microsoft.com>

Pull scheduler fix from Borislav Petkov:
 "A single fix to restore fairness between control groups with equal
  priority"

* tag 'sched_urgent_for_v5.13_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Correctly insert cfs_rq's to list on unthrottle

Pull irq fix from Borislav Petkov:
 "A single fix for GICv3 to not take an interrupt in an NMI context"

* tag 'irq_urgent_for_v5.13_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic-v3: Workaround inconsistent PMR setting on NMI entry

Pull x86 fixes from Borislav Petkov:
 "A first set of urgent fixes to the FPU/XSTATE handling mess^W code.
  (There's a lot more in the pipe):

   - Prevent corruption of the XSTATE buffer in signal handling by
     validating what is being copied from userspace first.

   - Invalidate other task's preserved FPU registers on XRSTOR failure
     (#PF) because latter can still modify some of them.

   - Restore the proper PKRU value in case userspace modified it

   - Reset FPU state when signal restoring fails

  Other:

   - Map EFI boot services data memory as encrypted in a SEV guest so
     that the guest can access it and actually boot properly

   - Two SGX correctness fixes: proper resources freeing and a NUMA fix"

* tag 'x86_urgent_for_v5.13_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Avoid truncating memblocks for SGX memory
  x86/sgx: Add missing xa_destroy() when virtual EPC is destroyed
  x86/fpu: Reset state for all signal restore failures
  x86/pkru: Write hardware init value to PKRU when xstate is init
  x86/process: Check PF_KTHREAD and not current->mm for kernel threads
  x86/fpu: Invalidate FPU state after a failed XRSTOR from a user buffer
  x86/fpu: Prevent state corruption in __fpu__restore_sig()
  x86/ioremap: Map EFI-reserved memory as encrypted for SEV

Pull powerpc fixes from Michael Ellerman:
 "Fix initrd corruption caused by our recent change to use relative jump
  labels.

  Fix a crash using perf record on systems without a hardware PMU
  backend.

  Rework our 64-bit signal handling slighty to make it more closely
  match the old behaviour, after the recent change to use unsafe user
  accessors.

  Thanks to Anastasia Kovaleva, Athira Rajeev, Christophe Leroy, Daniel
  Axtens, Greg Kurz, and Roman Bolshakov"

* tag 'powerpc-5.13-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/perf: Fix crash in perf_instruction_pointer() when ppmu is not set
  powerpc: Fix initrd corruption with relative jump labels
  powerpc/signal64: Copy siginfo before changing regs->nip
  powerpc/mem: Add back missing header to fix 'no previous prototype' error

Merge tag 'perf-tools-fixes-for-v5.13-2021-06-19' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull perf tools fixes from Arnaldo Carvalho de Melo:

 - Fix refcount usage when processing PERF_RECORD_KSYMBOL.

 - 'perf stat' metric group fixes.

 - Fix 'perf test' non-bash issue with stat bpf counters.

 - Update unistd, in.h and socket.h with the kernel sources, silencing
   perf build warnings.

* tag 'perf-tools-fixes-for-v5.13-2021-06-19' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux:
  tools headers UAPI: Sync linux/in.h copy with the kernel sources
  tools headers UAPI: Sync asm-generic/unistd.h with the kernel original
  perf beauty: Update copy of linux/socket.h with the kernel sources
  perf test: Fix non-bash issue with stat bpf counters
  perf machine: Fix refcount usage when processing PERF_RECORD_KSYMBOL
  perf metricgroup: Return error code from metricgroup__add_metric_sys_event_iter()
  perf metricgroup: Fix find_evsel_group() event selector

Pull RISC-V fixes from Palmer Dabbelt:

 - A build fix to always build modules with the 'medany' code model, as
   the module loader doesn't support 'medlow'.

 - A Kconfig warning fix for the SiFive errata.

 - A pair of fixes that for regressions to the recent memory layout
   changes.

 - A fix for the FU740 device tree.

* tag 'riscv-for-linus-5.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: dts: fu740: fix cache-controller interrupts
  riscv: Ensure BPF_JIT_REGION_START aligned with PMD size
  riscv: kasan: Fix MODULES_VADDR evaluation due to local variables' name
  riscv: sifive: fix Kconfig errata warning
  riscv32: Use medany C model for modules

Pull s390 fixes from Vasily Gorbik:

 - Fix zcrypt ioctl hang due to AP queue msg counter dropping below 0
   when pending requests are purged.

 - Two fixes for the machine check handler in the entry code.

* tag 's390-5.13-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/ap: Fix hanging ioctl caused by wrong msg counter
  s390/mcck: fix invalid KVM guest condition check
  s390/mcck: fix calculation of SIE critical section size

To pick the changes in:

  32182747 ("icmp: don't send out ICMP messages with a source address of 0.0.0.0")

That don't result in any change in tooling, as INADDR_ are not used to
generate id->string tables used by 'perf trace'.

This addresses this build warning:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/in.h' differs from latest version at 'include/uapi/linux/in.h'
  diff -u tools/include/uapi/linux/in.h include/uapi/linux/in.h

Cc: David S. Miller <davem@davemloft.net>
Cc: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To pick the changes in:

  8b1462b6 ("quota: finish disable quotactl_path syscall")

Those headers are used in some arches to generate the syscall table used
in 'perf trace' to translate syscall numbers into strings.

This addresses this perf build warning:

  Warning: Kernel ABI header at 'tools/include/uapi/asm-generic/unistd.h' differs from latest version at 'include/uapi/asm-generic/unistd.h'
  diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h

Cc: Jan Kara <jack@suse.cz>
Cc: Marcin Juszkiewicz <marcin@juszkiewicz.com.pl>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

To pick the changes in:

  ea6932d7 ("net: make get_net_ns return error if NET_NS is disabled")

That don't result in any changes in the tables generated from that
header.

This silences this perf build warning:

  Warning: Kernel ABI header at 'tools/perf/trace/beauty/include/linux/socket.h' differs from latest version at 'include/linux/socket.h'
  diff -u tools/perf/trace/beauty/include/linux/socket.h include/linux/socket.h

Cc: Changbin Du <changbin.du@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

$(( .. )) is a bash feature but the test's interpreter is !/bin/sh,
switch the code to use expr.
Signed-off-by: NIan Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: bpf@vger.kernel.org
Link: http://lore.kernel.org/lkml/20210617184216.2075588-1-irogers@google.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

ASan reported a memory leak of BPF-related ksymbols map and dso. The
leak is caused by refount never reaching 0, due to missing __put calls
in the function machine__process_ksymbol_register.

Once the dso is inserted in the map, dso__put() should be called
(map__new2() increases the refcount to 2).

The same thing applies for the map when it's inserted into maps
(maps__insert() increases the refcount to 2).

  $ sudo ./perf record -- sleep 5
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.025 MB perf.data (8 samples) ]

  =================================================================
  ==297735==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 6992 byte(s) in 19 object(s) allocated from:
      #0 0x4f43c7 in calloc (/home/user/linux/tools/perf/perf+0x4f43c7)
      #1 0x8e4e53 in map__new2 /home/user/linux/tools/perf/util/map.c:216:20
      #2 0x8cf68c in machine__process_ksymbol_register /home/user/linux/tools/perf/util/machine.c:778:10
      [...]

  Indirect leak of 8702 byte(s) in 19 object(s) allocated from:
      #0 0x4f43c7 in calloc (/home/user/linux/tools/perf/perf+0x4f43c7)
      #1 0x8728d7 in dso__new_id /home/user/linux/tools/perf/util/dso.c:1256:20
      #2 0x872015 in dso__new /home/user/linux/tools/perf/util/dso.c:1295:9
      #3 0x8cf623 in machine__process_ksymbol_register /home/user/linux/tools/perf/util/machine.c:774:21
      [...]

  Indirect leak of 1520 byte(s) in 19 object(s) allocated from:
      #0 0x4f43c7 in calloc (/home/user/linux/tools/perf/perf+0x4f43c7)
      #1 0x87b3da in symbol__new /home/user/linux/tools/perf/util/symbol.c:269:23
      #2 0x888954 in map__process_kallsym_symbol /home/user/linux/tools/perf/util/symbol.c:710:8
      [...]

  Indirect leak of 1406 byte(s) in 19 object(s) allocated from:
      #0 0x4f43c7 in calloc (/home/user/linux/tools/perf/perf+0x4f43c7)
      #1 0x87b3da in symbol__new /home/user/linux/tools/perf/util/symbol.c:269:23
      #2 0x8cfbd8 in machine__process_ksymbol_register /home/user/linux/tools/perf/util/machine.c:803:8
      [...]
Signed-off-by: NRiccardo Mancini <rickyman7@gmail.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tommi Rantala <tommi.t.rantala@nokia.com>
Link: http://lore.kernel.org/lkml/20210612173751.188582-1-rickyman7@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The error code is not set at all in the sys event iter function.

This may lead to an uninitialized value of "ret" in
metricgroup__add_metric() when no CPU metric is added.

Fix by properly setting the error code.

It is not necessary to init "ret" to 0 in metricgroup__add_metric(), as
if we have no CPU or sys event metric matching, then "has_match" should
be 0 and "ret" is set to -EINVAL.

However gcc cannot detect that it may not have been set after the
map_for_each_metric() loop for CPU metrics, which is strange.

Fixes: be335ec2 ("perf metricgroup: Support adding metrics for system PMUs")
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Acked-by: NIan Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/1623335580-187317-3-git-send-email-john.garry@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

The following command segfaults on my x86 broadwell:

  $ ./perf stat  -M frontend_bound,retiring,backend_bound,bad_speculation sleep 1
  WARNING: grouped events cpus do not match, disabling group:
    anon group { raw 0x10e }
    anon group { raw 0x10e }
  perf: util/evsel.c:1596: get_group_fd: Assertion `!(!leader->core.fd)' failed.
  Aborted (core dumped)

The issue shows itself as a use-after-free in evlist__check_cpu_maps(),
whereby the leader of an event selector (evsel) has been deleted (yet we
still attempt to verify for an evsel).

Fundamentally the problem comes from metricgroup__setup_events() ->
find_evsel_group(), and has developed from the previous fix attempt in
commit 9c880c24 ("perf metricgroup: Fix for metrics containing
duration_time").

The problem now is that the logic in checking if an evsel is in the same
group is subtly broken for the "cycles" event. For the "cycles" event,
the pmu_name is NULL; however the logic in find_evsel_group() may set an
event matched against "cycles" as used, when it should not be.

This leads to a condition where an evsel is set, yet its leader is not.

Fix the check for evsel pmu_name by not matching evsels when either has a
NULL pmu_name.

There is still a pre-existing metric issue whereby the ordering of the
metrics may break the 'stat' function, as discussed at:
https://lore.kernel.org/lkml/49c6fccb-b716-1bf0-18a6-cace1cdb66b9@huawei.com/

Fixes: 9c880c24 ("perf metricgroup: Fix for metrics containing duration_time")
Signed-off-by: NJohn Garry <john.garry@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> # On a Thinkpad T450S
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/1623335580-187317-2-git-send-email-john.garry@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>