kernel/linux.git/include, branch v4.9.220

compiler.h: fix error in BUILD_BUG_ON() reporting

2020-04-24T05:59:13+00:00

[ Upstream commit af9c5d2e3b355854ff0e4acfbfbfadcd5198a349 ] compiletime_assert() uses __LINE__ to create a unique function name. This means that if you have more than one BUILD_BUG_ON() in the same source line (which can happen if they appear e.g. in a macro), then the error message from the compiler might output the wrong condition. For this source file: #include #define macro() \ BUILD_BUG_ON(1); \ BUILD_BUG_ON(0); void foo() { macro(); } gcc would output: ./include/linux/compiler.h:350:38: error: call to `__compiletime_assert_9' declared with attribute error: BUILD_BUG_ON failed: 0 _compiletime_assert(condition, msg, __compiletime_assert_, __LINE__) However, it was not the BUILD_BUG_ON(0) that failed, so it should say 1 instead of 0. With this patch, we use __COUNTER__ instead of __LINE__, so each BUILD_BUG_ON() gets a different function name and the correct condition is printed: ./include/linux/compiler.h:350:38: error: call to `__compiletime_assert_0' declared with attribute error: BUILD_BUG_ON failed: 1 _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) Signed-off-by: Vegard Nossum Signed-off-by: Andrew Morton Reviewed-by: Masahiro Yamada Reviewed-by: Daniel Santos Cc: Rasmus Villemoes Cc: Ian Abbott Cc: Joe Perches Link: http://lkml.kernel.org/r/20200331112637.25047-1-vegard.nossum@oracle.com Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

percpu_counter: fix a data race at vm_committed_as

2020-04-24T05:59:12+00:00

[ Upstream commit 7e2345200262e4a6056580f0231cccdaffc825f3 ] "vm_committed_as.count" could be accessed concurrently as reported by KCSAN, BUG: KCSAN: data-race in __vm_enough_memory / percpu_counter_add_batch write to 0xffffffff9451c538 of 8 bytes by task 65879 on cpu 35: percpu_counter_add_batch+0x83/0xd0 percpu_counter_add_batch at lib/percpu_counter.c:91 __vm_enough_memory+0xb9/0x260 dup_mm+0x3a4/0x8f0 copy_process+0x2458/0x3240 _do_fork+0xaa/0x9f0 __do_sys_clone+0x125/0x160 __x64_sys_clone+0x70/0x90 do_syscall_64+0x91/0xb05 entry_SYSCALL_64_after_hwframe+0x49/0xbe read to 0xffffffff9451c538 of 8 bytes by task 66773 on cpu 19: __vm_enough_memory+0x199/0x260 percpu_counter_read_positive at include/linux/percpu_counter.h:81 (inlined by) __vm_enough_memory at mm/util.c:839 mmap_region+0x1b2/0xa10 do_mmap+0x45c/0x700 vm_mmap_pgoff+0xc0/0x130 ksys_mmap_pgoff+0x6e/0x300 __x64_sys_mmap+0x33/0x40 do_syscall_64+0x91/0xb05 entry_SYSCALL_64_after_hwframe+0x49/0xbe The read is outside percpu_counter::lock critical section which results in a data race. Fix it by adding a READ_ONCE() in percpu_counter_read_positive() which could also service as the existing compiler memory barrier. Signed-off-by: Qian Cai Signed-off-by: Andrew Morton Acked-by: Marco Elver Link: http://lkml.kernel.org/r/1582302724-2804-1-git-send-email-cai@lca.pw Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin

scsi: target: fix hang when multiple threads try to destroy the same iscsi session

2020-04-24T05:59:06+00:00

[ Upstream commit 57c46e9f33da530a2485fa01aa27b6d18c28c796 ] A number of hangs have been reported against the target driver; they are due to the fact that multiple threads may try to destroy the iscsi session at the same time. This may be reproduced for example when a "targetcli iscsi/iqn.../tpg1 disable" command is executed while a logout operation is underway. When this happens, two or more threads may end up sleeping and waiting for iscsit_close_connection() to execute "complete(session_wait_comp)". Only one of the threads will wake up and proceed to destroy the session structure, the remaining threads will hang forever. Note that if the blocked threads are somehow forced to wake up with complete_all(), they will try to free the same iscsi session structure destroyed by the first thread, causing double frees, memory corruptions etc... With this patch, the threads that want to destroy the iscsi session will increase the session refcount and will set the "session_close" flag to 1; then they wait for the driver to close the remaining active connections. When the last connection is closed, iscsit_close_connection() will wake up all the threads and will wait for the session's refcount to reach zero; when this happens, iscsit_close_connection() will destroy the session structure because no one is referencing it anymore. INFO: task targetcli:5971 blocked for more than 120 seconds. Tainted: P OE 4.15.0-72-generic #81~16.04.1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. targetcli D 0 5971 1 0x00000080 Call Trace: __schedule+0x3d6/0x8b0 ? vprintk_func+0x44/0xe0 schedule+0x36/0x80 schedule_timeout+0x1db/0x370 ? __dynamic_pr_debug+0x8a/0xb0 wait_for_completion+0xb4/0x140 ? wake_up_q+0x70/0x70 iscsit_free_session+0x13d/0x1a0 [iscsi_target_mod] iscsit_release_sessions_for_tpg+0x16b/0x1e0 [iscsi_target_mod] iscsit_tpg_disable_portal_group+0xca/0x1c0 [iscsi_target_mod] lio_target_tpg_enable_store+0x66/0xe0 [iscsi_target_mod] configfs_write_file+0xb9/0x120 __vfs_write+0x1b/0x40 vfs_write+0xb8/0x1b0 SyS_write+0x5c/0xe0 do_syscall_64+0x73/0x130 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 Link: https://lore.kernel.org/r/20200313170656.9716-3-mlombard@redhat.com Reported-by: Matt Coleman Tested-by: Matt Coleman Tested-by: Rahul Kundu Signed-off-by: Maurizio Lombardi Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

net: ipv6: do not consider routes via gateways for anycast address check

2020-04-24T05:59:02+00:00

[ Upstream commit 03e2a984b6165621f287fadf5f4b5cd8b58dcaba ] The behaviour for what is considered an anycast address changed in commit 45e4fd26683c ("ipv6: Only create RTF_CACHE routes after encountering pmtu exception"). This now considers the first address in a subnet where there is a route via a gateway to be an anycast address. This breaks path MTU discovery and traceroutes when a host in a remote network uses the address at the start of a prefix (eg 2600:: advertised as 2600::/48 in the DFZ) as ICMP errors will not be sent to anycast addresses. This patch excludes any routes with a gateway, or via point to point links, like the behaviour previously from rt6_is_gw_or_nonexthop in net/ipv6/route.c. This can be tested with: ip link add v1 type veth peer name v2 ip netns add test ip netns exec test ip link set lo up ip link set v2 netns test ip link set v1 up ip netns exec test ip link set v2 up ip addr add 2001:db8::1/64 dev v1 nodad ip addr add 2001:db8:100:: dev lo nodad ip netns exec test ip addr add 2001:db8::2/64 dev v2 nodad ip netns exec test ip route add unreachable 2001:db8:1::1 ip netns exec test ip route add 2001:db8:100::/64 via 2001:db8::1 ip netns exec test sysctl net.ipv6.conf.all.forwarding=1 ip route add 2001:db8:1::1 via 2001:db8::2 ping -I 2001:db8::1 2001:db8:1::1 -c1 ping -I 2001:db8:100:: 2001:db8:1::1 -c1 ip addr delete 2001:db8:100:: dev lo ip netns delete test Currently the first ping will get back a destination unreachable ICMP error, but the second will never get a response, with "icmp6_send: acast source" logged. After this patch, both get destination unreachable ICMP replies. Fixes: 45e4fd26683c ("ipv6: Only create RTF_CACHE routes after encountering pmtu exception") Signed-off-by: Tim Stallard Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

signal: Extend exec_id to 64bits

2020-04-24T05:58:54+00:00

commit d1e7fd6462ca9fc76650fbe6ca800e35b24267da upstream. Replace the 32bit exec_id with a 64bit exec_id to make it impossible to wrap the exec_id counter. With care an attacker can cause exec_id wrap and send arbitrary signals to a newly exec'd parent. This bypasses the signal sending checks if the parent changes their credentials during exec. The severity of this problem can been seen that in my limited testing of a 32bit exec_id it can take as little as 19s to exec 65536 times. Which means that it can take as little as 14 days to wrap a 32bit exec_id. Adam Zabrocki has succeeded wrapping the self_exe_id in 7 days. Even my slower timing is in the uptime of a typical server. Which means self_exec_id is simply a speed bump today, and if exec gets noticably faster self_exec_id won't even be a speed bump. Extending self_exec_id to 64bits introduces a problem on 32bit architectures where reading self_exec_id is no longer atomic and can take two read instructions. Which means that is is possible to hit a window where the read value of exec_id does not match the written value. So with very lucky timing after this change this still remains expoiltable. I have updated the update of exec_id on exec to use WRITE_ONCE and the read of exec_id in do_notify_parent to use READ_ONCE to make it clear that there is no locking between these two locations. Link: https://lore.kernel.org/kernel-hardening/20200324215049.GA3710@pi3.com.pl Fixes: 2.3.23pre2 Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" Signed-off-by: Greg Kroah-Hartman

thermal: devfreq_cooling: inline all stubs for CONFIG_DEVFREQ_THERMAL=n

2020-04-24T05:58:53+00:00

commit 3f5b9959041e0db6dacbea80bb833bff5900999f upstream. When CONFIG_DEVFREQ_THERMAL is disabled all functions except of_devfreq_cooling_register_power() were already inlined. Also inline the last function to avoid compile errors when multiple drivers call of_devfreq_cooling_register_power() when CONFIG_DEVFREQ_THERMAL is not set. Compilation failed with the following message: multiple definition of `of_devfreq_cooling_register_power' (which then lists all usages of of_devfreq_cooling_register_power()) Thomas Zimmermann reported this problem [0] on a kernel config with CONFIG_DRM_LIMA={m,y}, CONFIG_DRM_PANFROST={m,y} and CONFIG_DEVFREQ_THERMAL=n after both, the lima and panfrost drivers gained devfreq cooling support. [0] https://www.spinics.net/lists/dri-devel/msg252825.html Fixes: a76caf55e5b356 ("thermal: Add devfreq cooling") Cc: stable@vger.kernel.org Reported-by: Thomas Zimmermann Signed-off-by: Martin Blumenstingl Tested-by: Thomas Zimmermann Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20200403205133.1101808-1-martin.blumenstingl@googlemail.com Signed-off-by: Greg Kroah-Hartman

coresight: do not use the BIT() macro in the UAPI header

2020-04-13T08:32:53+00:00

commit 9b6eaaf3db5e5888df7bca7fed7752a90f7fd871 upstream. The BIT() macro definition is not available for the UAPI headers (moreover, it can be defined differently in the user space); replace its usage with the _BITUL() macro that is defined in . Fixes: 237483aa5cf4 ("coresight: stm: adding driver for CoreSight STM component") Signed-off-by: Eugene Syromiatnikov Cc: stable Reviewed-by: Mathieu Poirier Link: https://lore.kernel.org/r/20200324042213.GA10452@asgard.redhat.com Signed-off-by: Greg Kroah-Hartman

locking/atomic, kref: Add kref_read()

2020-04-02T15:20:40+00:00

commit 2c935bc57221cc2edc787c72ea0e2d30cdcd3d5e upstream. Since we need to change the implementation, stop exposing internals. Provide kref_read() to read the current reference count; typically used for debug messages. Kills two anti-patterns: atomic_read(&kref->refcount) kref->refcount.counter Signed-off-by: Peter Zijlstra (Intel) Cc: Andrew Morton Cc: Greg Kroah-Hartman Cc: Linus Torvalds Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar [only add kref_read() to kref.h for stable backports - gregkh] Signed-off-by: Greg Kroah-Hartman

vt: switch vt_dont_switch to bool

2020-04-02T15:20:39+00:00

commit f400991bf872debffb01c46da882dc97d7e3248e upstream. vt_dont_switch is pure boolean, no need for whole char. Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20200219073951.16151-6-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

vt: selection, introduce vc_is_sel

2020-04-02T15:20:39+00:00

commit dce05aa6eec977f1472abed95ccd71276b9a3864 upstream. Avoid global variables (namely sel_cons) by introducing vc_is_sel. It checks whether the parameter is the current selection console. This will help putting sel_cons to a struct later. Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20200219073951.16151-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman