<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/include, branch v3.18.140</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v3.18.140</id>
<link rel='self' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v3.18.140'/>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/'/>
<updated>2019-05-16T07:17:21Z</updated>
<entry>
<title>Bluetooth: Align minimum encryption key size for LE and BR/EDR connections</title>
<updated>2019-05-16T07:17:21Z</updated>
<author>
<name>Marcel Holtmann</name>
<email>marcel@holtmann.org</email>
</author>
<published>2019-04-24T20:19:17Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=b16a6c99f88c16c9b4f736226b736d0c53320614'/>
<id>urn:sha1:b16a6c99f88c16c9b4f736226b736d0c53320614</id>
<content type='text'>
commit d5bb334a8e171b262e48f378bd2096c0ea458265 upstream.

The minimum encryption key size for LE connections is 56 bits and to
align LE with BR/EDR, enforce 56 bits of minimum encryption key size for
BR/EDR connections as well.

Signed-off-by: Marcel Holtmann &lt;marcel@holtmann.org&gt;
Signed-off-by: Johan Hedberg &lt;johan.hedberg@intel.com&gt;
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>USB: core: Fix bug caused by duplicate interface PM usage counter</title>
<updated>2019-05-16T07:17:18Z</updated>
<author>
<name>Alan Stern</name>
<email>stern@rowland.harvard.edu</email>
</author>
<published>2019-04-19T17:52:38Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=bc1c5d1ac4772cbc39e485ee94bdf2e9d8a2cd7d'/>
<id>urn:sha1:bc1c5d1ac4772cbc39e485ee94bdf2e9d8a2cd7d</id>
<content type='text'>
commit c2b71462d294cf517a0bc6e4fd6424d7cee5596f upstream.

The syzkaller fuzzer reported a bug in the USB hub driver which turned
out to be caused by a negative runtime-PM usage counter.  This allowed
a hub to be runtime suspended at a time when the driver did not expect
it.  The symptom is a WARNING issued because the hub's status URB is
submitted while it is already active:

	URB 0000000031fb463e submitted while active
	WARNING: CPU: 0 PID: 2917 at drivers/usb/core/urb.c:363

The negative runtime-PM usage count was caused by an unfortunate
design decision made when runtime PM was first implemented for USB.
At that time, USB class drivers were allowed to unbind from their
interfaces without balancing the usage counter (i.e., leaving it with
a positive count).  The core code would take care of setting the
counter back to 0 before allowing another driver to bind to the
interface.

Later on when runtime PM was implemented for the entire kernel, the
opposite decision was made: Drivers were required to balance their
runtime-PM get and put calls.  In order to maintain backward
compatibility, however, the USB subsystem adapted to the new
implementation by keeping an independent usage counter for each
interface and using it to automatically adjust the normal usage
counter back to 0 whenever a driver was unbound.

This approach involves duplicating information, but what is worse, it
doesn't work properly in cases where a USB class driver delays
decrementing the usage counter until after the driver's disconnect()
routine has returned and the counter has been adjusted back to 0.
Doing so would cause the usage counter to become negative.  There's
even a warning about this in the USB power management documentation!

As it happens, this is exactly what the hub driver does.  The
kick_hub_wq() routine increments the runtime-PM usage counter, and the
corresponding decrement is carried out by hub_event() in the context
of the hub_wq work-queue thread.  This work routine may sometimes run
after the driver has been unbound from its interface, and when it does
it causes the usage counter to go negative.

It is not possible for hub_disconnect() to wait for a pending
hub_event() call to finish, because hub_disconnect() is called with
the device lock held and hub_event() acquires that lock.  The only
feasible fix is to reverse the original design decision: remove the
duplicate interface-specific usage counter and require USB drivers to
balance their runtime PM gets and puts.  As far as I know, all
existing drivers currently do this.

Signed-off-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Reported-and-tested-by: syzbot+7634edaea4d0b341c625@syzkaller.appspotmail.com
CC: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>x86/kprobes: Verify stack frame on kretprobe</title>
<updated>2019-04-27T07:30:30Z</updated>
<author>
<name>Masami Hiramatsu</name>
<email>mhiramat@kernel.org</email>
</author>
<published>2019-02-23T16:49:52Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=71dc273de2d243657584fb206cd090150bb66a0d'/>
<id>urn:sha1:71dc273de2d243657584fb206cd090150bb66a0d</id>
<content type='text'>
commit 3ff9c075cc767b3060bdac12da72fc94dd7da1b8 upstream.

Verify the stack frame pointer on kretprobe trampoline handler,
If the stack frame pointer does not match, it skips the wrong
entry and tries to find correct one.

This can happen if user puts the kretprobe on the function
which can be used in the path of ftrace user-function call.
Such functions should not be probed, so this adds a warning
message that reports which function should be blacklisted.

Tested-by: Andrea Righi &lt;righi.andrea@gmail.com&gt;
Signed-off-by: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Acked-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Mathieu Desnoyers &lt;mathieu.desnoyers@efficios.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/155094059185.6137.15527904013362842072.stgit@devbox
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>appletalk: Fix compile regression</title>
<updated>2019-04-27T07:30:29Z</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2019-03-06T10:52:36Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=27c72725a63a1b0b1c16878e61501ed0d1e0691e'/>
<id>urn:sha1:27c72725a63a1b0b1c16878e61501ed0d1e0691e</id>
<content type='text'>
[ Upstream commit 27da0d2ef998e222a876c0cec72aa7829a626266 ]

A bugfix just broke compilation of appletalk when CONFIG_SYSCTL
is disabled:

In file included from net/appletalk/ddp.c:65:
net/appletalk/ddp.c: In function 'atalk_init':
include/linux/atalk.h:164:34: error: expected expression before 'do'
 #define atalk_register_sysctl()  do { } while(0)
                                  ^~
net/appletalk/ddp.c:1934:7: note: in expansion of macro 'atalk_register_sysctl'
  rc = atalk_register_sysctl();

This is easier to avoid by using conventional inline functions
as stubs rather than macros. The header already has inline
functions for other purposes, so I'm changing over all the
macros for consistency.

Fixes: 6377f787aeb9 ("appletalk: Fix use-after-free in atalk_proc_exit")
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>include/linux/swap.h: use offsetof() instead of custom __swapoffset macro</title>
<updated>2019-04-27T07:30:29Z</updated>
<author>
<name>Pi-Hsun Shih</name>
<email>pihsun@chromium.org</email>
</author>
<published>2019-03-13T18:44:33Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=8620392634e75cd4b08af3c070af87814593125e'/>
<id>urn:sha1:8620392634e75cd4b08af3c070af87814593125e</id>
<content type='text'>
[ Upstream commit a4046c06be50a4f01d435aa7fe57514818e6cc82 ]

Use offsetof() to calculate offset of a field to take advantage of
compiler built-in version when possible, and avoid UBSAN warning when
compiling with Clang:

  UBSAN: Undefined behaviour in mm/swapfile.c:3010:38
  member access within null pointer of type 'union swap_header'
  CPU: 6 PID: 1833 Comm: swapon Tainted: G S                4.19.23 #43
  Call trace:
   dump_backtrace+0x0/0x194
   show_stack+0x20/0x2c
   __dump_stack+0x20/0x28
   dump_stack+0x70/0x94
   ubsan_epilogue+0x14/0x44
   ubsan_type_mismatch_common+0xf4/0xfc
   __ubsan_handle_type_mismatch_v1+0x34/0x54
   __se_sys_swapon+0x654/0x1084
   __arm64_sys_swapon+0x1c/0x24
   el0_svc_common+0xa8/0x150
   el0_svc_compat_handler+0x2c/0x38
   el0_svc_compat+0x8/0x18

Link: http://lkml.kernel.org/r/20190312081902.223764-1-pihsun@chromium.org
Signed-off-by: Pi-Hsun Shih &lt;pihsun@chromium.org&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Reviewed-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>appletalk: Fix use-after-free in atalk_proc_exit</title>
<updated>2019-04-27T07:30:29Z</updated>
<author>
<name>YueHaibing</name>
<email>yuehaibing@huawei.com</email>
</author>
<published>2019-03-01T02:57:57Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=ab885986b6308c902364b4a91d73fae3003da9fe'/>
<id>urn:sha1:ab885986b6308c902364b4a91d73fae3003da9fe</id>
<content type='text'>
[ Upstream commit 6377f787aeb945cae7abbb6474798de129e1f3ac ]

KASAN report this:

BUG: KASAN: use-after-free in pde_subdir_find+0x12d/0x150 fs/proc/generic.c:71
Read of size 8 at addr ffff8881f41fe5b0 by task syz-executor.0/2806

CPU: 0 PID: 2806 Comm: syz-executor.0 Not tainted 5.0.0-rc7+ #45
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xfa/0x1ce lib/dump_stack.c:113
 print_address_description+0x65/0x270 mm/kasan/report.c:187
 kasan_report+0x149/0x18d mm/kasan/report.c:317
 pde_subdir_find+0x12d/0x150 fs/proc/generic.c:71
 remove_proc_entry+0xe8/0x420 fs/proc/generic.c:667
 atalk_proc_exit+0x18/0x820 [appletalk]
 atalk_exit+0xf/0x5a [appletalk]
 __do_sys_delete_module kernel/module.c:1018 [inline]
 __se_sys_delete_module kernel/module.c:961 [inline]
 __x64_sys_delete_module+0x3dc/0x5e0 kernel/module.c:961
 do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x462e99
Code: f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb2de6b9c58 EFLAGS: 00000246 ORIG_RAX: 00000000000000b0
RAX: ffffffffffffffda RBX: 000000000073bf00 RCX: 0000000000462e99
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200001c0
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb2de6ba6bc
R13: 00000000004bccaa R14: 00000000006f6bc8 R15: 00000000ffffffff

Allocated by task 2806:
 set_track mm/kasan/common.c:85 [inline]
 __kasan_kmalloc.constprop.3+0xa0/0xd0 mm/kasan/common.c:496
 slab_post_alloc_hook mm/slab.h:444 [inline]
 slab_alloc_node mm/slub.c:2739 [inline]
 slab_alloc mm/slub.c:2747 [inline]
 kmem_cache_alloc+0xcf/0x250 mm/slub.c:2752
 kmem_cache_zalloc include/linux/slab.h:730 [inline]
 __proc_create+0x30f/0xa20 fs/proc/generic.c:408
 proc_mkdir_data+0x47/0x190 fs/proc/generic.c:469
 0xffffffffc10c01bb
 0xffffffffc10c0166
 do_one_initcall+0xfa/0x5ca init/main.c:887
 do_init_module+0x204/0x5f6 kernel/module.c:3460
 load_module+0x66b2/0x8570 kernel/module.c:3808
 __do_sys_finit_module+0x238/0x2a0 kernel/module.c:3902
 do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 2806:
 set_track mm/kasan/common.c:85 [inline]
 __kasan_slab_free+0x130/0x180 mm/kasan/common.c:458
 slab_free_hook mm/slub.c:1409 [inline]
 slab_free_freelist_hook mm/slub.c:1436 [inline]
 slab_free mm/slub.c:2986 [inline]
 kmem_cache_free+0xa6/0x2a0 mm/slub.c:3002
 pde_put+0x6e/0x80 fs/proc/generic.c:647
 remove_proc_entry+0x1d3/0x420 fs/proc/generic.c:684
 0xffffffffc10c031c
 0xffffffffc10c0166
 do_one_initcall+0xfa/0x5ca init/main.c:887
 do_init_module+0x204/0x5f6 kernel/module.c:3460
 load_module+0x66b2/0x8570 kernel/module.c:3808
 __do_sys_finit_module+0x238/0x2a0 kernel/module.c:3902
 do_syscall_64+0x147/0x600 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8881f41fe500
 which belongs to the cache proc_dir_entry of size 256
The buggy address is located 176 bytes inside of
 256-byte region [ffff8881f41fe500, ffff8881f41fe600)
The buggy address belongs to the page:
page:ffffea0007d07f80 count:1 mapcount:0 mapping:ffff8881f6e69a00 index:0x0
flags: 0x2fffc0000000200(slab)
raw: 02fffc0000000200 dead000000000100 dead000000000200 ffff8881f6e69a00
raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881f41fe480: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8881f41fe500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
&gt;ffff8881f41fe580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff8881f41fe600: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 ffff8881f41fe680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

It should check the return value of atalk_proc_init fails,
otherwise atalk_exit will trgger use-after-free in pde_subdir_find
while unload the module.This patch fix error cleanup path of atalk_init

Reported-by: Hulk Robot &lt;hulkci@huawei.com&gt;
Signed-off-by: YueHaibing &lt;yuehaibing@huawei.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>string: drop __must_check from strscpy() and restore strscpy() usages in cgroup</title>
<updated>2019-04-27T07:30:27Z</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2018-01-09T15:21:15Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=3107d24b7bb8e2588f4d54bb33357c8da9a475ec'/>
<id>urn:sha1:3107d24b7bb8e2588f4d54bb33357c8da9a475ec</id>
<content type='text'>
commit 08a77676f9c5fc69a681ccd2cd8140e65dcb26c7 upstream.

e7fd37ba1217 ("cgroup: avoid copying strings longer than the buffers")
converted possibly unsafe strncpy() usages in cgroup to strscpy().
However, although the callsites are completely fine with truncated
copied, because strscpy() is marked __must_check, it led to the
following warnings.

  kernel/cgroup/cgroup.c: In function ‘cgroup_file_name’:
  kernel/cgroup/cgroup.c:1400:10: warning: ignoring return value of ‘strscpy’, declared with attribute warn_unused_result [-Wunused-result]
     strscpy(buf, cft-&gt;name, CGROUP_FILE_NAME_MAX);
	       ^

To avoid the warnings, 50034ed49645 ("cgroup: use strlcpy() instead of
strscpy() to avoid spurious warning") switched them to strlcpy().

strlcpy() is worse than strlcpy() because it unconditionally runs
strlen() on the source string, and the only reason we switched to
strlcpy() here was because it was lacking __must_check, which doesn't
reflect any material differences between the two function.  It's just
that someone added __must_check to strscpy() and not to strlcpy().

These basic string copy operations are used in variety of ways, and
one of not-so-uncommon use cases is safely handling truncated copies,
where the caller naturally doesn't care about the return value.  The
__must_check doesn't match the actual use cases and forces users to
opt for inferior variants which lack __must_check by happenstance or
spread ugly (void) casts.

Remove __must_check from strscpy() and restore strscpy() usages in
cgroup.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Suggested-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Ma Shimiao &lt;mashimiao.fnst@cn.fujitsu.com&gt;
Cc: Arnd Bergmann &lt;arnd@arndb.de&gt;
Cc: Chris Metcalf &lt;cmetcalf@ezchip.com&gt;
[backport only the string.h portion to remove build warnings starting to show up - gregkh]
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
</entry>
<entry>
<title>netns: provide pure entropy for net_hash_mix()</title>
<updated>2019-04-27T07:30:26Z</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2019-03-27T15:21:30Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=c2bca92ba948f3def1f99f6b429ec39e07354dc2'/>
<id>urn:sha1:c2bca92ba948f3def1f99f6b429ec39e07354dc2</id>
<content type='text'>
[ Upstream commit 355b98553789b646ed97ad801a619ff898471b92 ]

net_hash_mix() currently uses kernel address of a struct net,
and is used in many places that could be used to reveal this
address to a patient attacker, thus defeating KASLR, for
the typical case (initial net namespace, &amp;init_net is
not dynamically allocated)

I believe the original implementation tried to avoid spending
too many cycles in this function, but security comes first.

Also provide entropy regardless of CONFIG_NET_NS.

Fixes: 0b4419162aa6 ("netns: introduce the net_hash_mix "salt" for hashes")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reported-by: Amit Klein &lt;aksecurity@gmail.com&gt;
Reported-by: Benny Pinkas &lt;benny@pinkas.net&gt;
Cc: Pavel Emelyanov &lt;xemul@openvz.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>lib/string.c: implement a basic bcmp</title>
<updated>2019-04-27T07:30:25Z</updated>
<author>
<name>Nick Desaulniers</name>
<email>ndesaulniers@google.com</email>
</author>
<published>2019-04-06T01:38:45Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=8a34ae9b87f04204d32bf5e431761716a9045dfc'/>
<id>urn:sha1:8a34ae9b87f04204d32bf5e431761716a9045dfc</id>
<content type='text'>
[ Upstream commit 5f074f3e192f10c9fade898b9b3b8812e3d83342 ]

A recent optimization in Clang (r355672) lowers comparisons of the
return value of memcmp against zero to comparisons of the return value
of bcmp against zero.  This helps some platforms that implement bcmp
more efficiently than memcmp.  glibc simply aliases bcmp to memcmp, but
an optimized implementation is in the works.

This results in linkage failures for all targets with Clang due to the
undefined symbol.  For now, just implement bcmp as a tailcail to memcmp
to unbreak the build.  This routine can be further optimized in the
future.

Other ideas discussed:

 * A weak alias was discussed, but breaks for architectures that define
   their own implementations of memcmp since aliases to declarations are
   not permitted (only definitions). Arch-specific memcmp
   implementations typically declare memcmp in C headers, but implement
   them in assembly.

 * -ffreestanding also is used sporadically throughout the kernel.

 * -fno-builtin-bcmp doesn't work when doing LTO.

Link: https://bugs.llvm.org/show_bug.cgi?id=41035
Link: https://code.woboq.org/userspace/glibc/string/memcmp.c.html#bcmp
Link: https://github.com/llvm/llvm-project/commit/8e16d73346f8091461319a7dfc4ddd18eedcff13
Link: https://github.com/ClangBuiltLinux/linux/issues/416
Link: http://lkml.kernel.org/r/20190313211335.165605-1-ndesaulniers@google.com
Signed-off-by: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Reported-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Reported-by: Adhemerval Zanella &lt;adhemerval.zanella@linaro.org&gt;
Suggested-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Suggested-by: James Y Knight &lt;jyknight@google.com&gt;
Suggested-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Suggested-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Suggested-by: Rasmus Villemoes &lt;linux@rasmusvillemoes.dk&gt;
Acked-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Reviewed-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Tested-by: Nathan Chancellor &lt;natechancellor@gmail.com&gt;
Reviewed-by: Masahiro Yamada &lt;yamada.masahiro@socionext.com&gt;
Reviewed-by: Andy Shevchenko &lt;andriy.shevchenko@linux.intel.com&gt;
Cc: David Laight &lt;David.Laight@ACULAB.COM&gt;
Cc: Rasmus Villemoes &lt;linux@rasmusvillemoes.dk&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Cc: Alexander Shishkin &lt;alexander.shishkin@linux.intel.com&gt;
Cc: Dan Williams &lt;dan.j.williams@intel.com&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
<entry>
<title>tracing: kdb: Fix ftdump to not sleep</title>
<updated>2019-04-27T07:30:19Z</updated>
<author>
<name>Douglas Anderson</name>
<email>dianders@chromium.org</email>
</author>
<published>2019-03-08T19:32:04Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=33da87e946befcbd68fb948aa874130f06fdfcd2'/>
<id>urn:sha1:33da87e946befcbd68fb948aa874130f06fdfcd2</id>
<content type='text'>
[ Upstream commit 31b265b3baaf55f209229888b7ffea523ddab366 ]

As reported back in 2016-11 [1], the "ftdump" kdb command triggers a
BUG for "sleeping function called from invalid context".

kdb's "ftdump" command wants to call ring_buffer_read_prepare() in
atomic context.  A very simple solution for this is to add allocation
flags to ring_buffer_read_prepare() so kdb can call it without
triggering the allocation error.  This patch does that.

Note that in the original email thread about this, it was suggested
that perhaps the solution for kdb was to either preallocate the buffer
ahead of time or create our own iterator.  I'm hoping that this
alternative of adding allocation flags to ring_buffer_read_prepare()
can be considered since it means I don't need to duplicate more of the
core trace code into "trace_kdb.c" (for either creating my own
iterator or re-preparing a ring allocator whose memory was already
allocated).

NOTE: another option for kdb is to actually figure out how to make it
reuse the existing ftrace_dump() function and totally eliminate the
duplication.  This sounds very appealing and actually works (the "sr
z" command can be seen to properly dump the ftrace buffer).  The
downside here is that ftrace_dump() fully consumes the trace buffer.
Unless that is changed I'd rather not use it because it means "ftdump
| grep xyz" won't be very useful to search the ftrace buffer since it
will throw away the whole trace on the first grep.  A future patch to
dump only the last few lines of the buffer will also be hard to
implement.

[1] https://lkml.kernel.org/r/20161117191605.GA21459@google.com

Link: http://lkml.kernel.org/r/20190308193205.213659-1-dianders@chromium.org

Reported-by: Brian Norris &lt;briannorris@chromium.org&gt;
Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Signed-off-by: Steven Rostedt (VMware) &lt;rostedt@goodmis.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
</entry>
</feed>
