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Christian Brauner 793c823293 binder: fix CONFIG_ANDROID_BINDER_DEVICES
Several users have tried to only rely on binderfs to provide binder devices
and set CONFIG_ANDROID_BINDER_DEVICES="" empty. This is a great use-case of
binderfs and one that was always intended to work. However, this is
currently not possible since setting CONFIG_ANDROID_BINDER_DEVICES="" emtpy
will simply panic the kernel:

kobject: (00000000028c2f79): attempted to be registered with empty name!
WARNING: CPU: 7 PID: 1703 at lib/kobject.c:228 kobject_add_internal+0x288/0x2b0
Modules linked in: binder_linux(+) bridge stp llc ipmi_ssif gpio_ich dcdbas coretemp kvm_intel kvm irqbypass serio_raw input_leds lpc_ich i5100_edac mac_hid ipmi_si ipmi_devintf ipmi_msghandler sch_fq_codel ib_i
CPU: 7 PID: 1703 Comm: modprobe Not tainted 5.0.0-rc2-brauner-binderfs #263
Hardware name: Dell      DCS XS24-SC2          /XS24-SC2              , BIOS S59_3C20 04/07/2011
RIP: 0010:kobject_add_internal+0x288/0x2b0
Code: 12 95 48 c7 c7 78 63 3b 95 e8 77 35 71 ff e9 91 fe ff ff 0f 0b eb a7 0f 0b eb 9a 48 89 de 48 c7 c7 00 63 3b 95 e8 f8 95 6a ff <0f> 0b 41 bc ea ff ff ff e9 6d fe ff ff 41 bc fe ff ff ff e9 62 fe
RSP: 0018:ffff973f84237a30 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff8b53e2472010 RCX: 0000000000000006
RDX: 0000000000000007 RSI: 0000000000000086 RDI: ffff8b53edbd63a0
RBP: ffff973f84237a60 R08: 0000000000000342 R09: 0000000000000004
R10: ffff973f84237af0 R11: 0000000000000001 R12: 0000000000000000
R13: ffff8b53e9f1a1e0 R14: 00000000e9f1a1e0 R15: 0000000000a00037
FS:  00007fbac36f7540(0000) GS:ffff8b53edbc0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbac364cfa7 CR3: 00000004a6d48000 CR4: 00000000000406e0
Call Trace:
 kobject_add+0x71/0xd0
 ? _cond_resched+0x19/0x40
 ? mutex_lock+0x12/0x40
 device_add+0x12e/0x6b0
 device_create_groups_vargs+0xe4/0xf0
 device_create_with_groups+0x3f/0x60
 ? _cond_resched+0x19/0x40
 misc_register+0x140/0x180
 binder_init+0x1ed/0x2d4 [binder_linux]
 ? trace_event_define_fields_binder_transaction_fd_send+0x8e/0x8e [binder_linux]
 do_one_initcall+0x4a/0x1c9
 ? _cond_resched+0x19/0x40
 ? kmem_cache_alloc_trace+0x151/0x1c0
 do_init_module+0x5f/0x216
 load_module+0x223d/0x2b20
 __do_sys_finit_module+0xfc/0x120
 ? __do_sys_finit_module+0xfc/0x120
 __x64_sys_finit_module+0x1a/0x20
 do_syscall_64+0x5a/0x120
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fbac3202839
Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 1f f6 2c 00 f7 d8 64 89 01 48
RSP: 002b:00007ffd1494a908 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
RAX: ffffffffffffffda RBX: 000055b629ebec60 RCX: 00007fbac3202839
RDX: 0000000000000000 RSI: 000055b629c20d2e RDI: 0000000000000003
RBP: 000055b629c20d2e R08: 0000000000000000 R09: 000055b629ec2310
R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000
R13: 000055b629ebed70 R14: 0000000000040000 R15: 000055b629ebec60

So check for the empty string since strsep() will otherwise return the
emtpy string which will cause kobject_add_internal() to panic when trying
to add a kobject with an emtpy name.

Fixes: ac4812c5ff ("binder: Support multiple /dev instances")
Cc: Martijn Coenen <maco@google.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Todd Kjos <tkjos@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-30 15:21:01 +01:00
Documentation drm fixes. msm, sun4i, amdgpu, i915 gvt 2019-01-25 12:19:10 +13:00
LICENSES This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
arch Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-01-27 12:02:00 -08:00
block Revert "block: cover another queue enter recursion via BIO_QUEUE_ENTERED" 2019-01-27 06:35:28 -07:00
certs kbuild: remove redundant target cleaning on failure 2019-01-06 09:46:51 +09:00
crypto crypto: sm3 - fix undefined shift by >= width of value 2019-01-10 21:37:32 +08:00
drivers binder: fix CONFIG_ANDROID_BINDER_DEVICES 2019-01-30 15:21:01 +01:00
firmware kbuild: change filechk to surround the given command with { } 2019-01-06 09:46:51 +09:00
fs a set of small smb3 fixes, some fixing various crediting issues discovered during xfstest runs, five for stable 2019-01-26 15:38:22 -08:00
include Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-01-27 11:52:50 -08:00
init kbuild: Disable LD_DEAD_CODE_DATA_ELIMINATION with ftrace & GCC <= 4.7 2019-01-14 10:37:09 +09:00
ipc ipc: IPCMNI limit check for semmni 2018-10-31 08:54:14 -07:00
kernel Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-01-27 11:55:06 -08:00
lib XArray updates for 5.0-rc3 2019-01-22 17:08:30 +13:00
mm for-linus-20190125 2019-01-26 12:42:41 -08:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-01-27 08:59:12 -08:00
samples samples/bpf: workaround clang asm goto compilation errors 2019-01-15 20:57:30 +01:00
scripts Bug fixes for gcc-plugins 2019-01-21 13:07:03 +13:00
security Merge branch 'fixes-v5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-01-17 16:54:58 +12:00
sound sound fixes for 5.0-rc4 2019-01-25 05:55:26 +13:00
tools selftests: add binderfs selftests 2019-01-30 15:19:56 +01:00
usr user/Makefile: Fix typo and capitalization in comment section 2018-12-11 00:18:03 +09:00
virt KVM: validate userspace input in kvm_clear_dirty_log_protect() 2019-01-11 18:38:07 +01:00
.clang-format clang-format: Update .clang-format with the latest for_each macro list 2019-01-19 19:26:06 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support for DT binding schema checks 2018-12-13 09:41:32 -06:00
.mailmap A few early MIPS fixes for 4.21: 2019-01-05 12:48:25 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Add CREDITS entry for Shaohua Li 2019-01-04 14:27:09 -07:00
Kbuild kbuild: use assignment instead of define ... endef for filechk_* rules 2019-01-06 10:22:35 +09:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-01-27 08:59:12 -08:00
Makefile Linux 5.0-rc4 2019-01-27 15:18:05 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.