linux-stable.git/arch/um/kernel, branch linux-4.9.y

UM: cpuinfo: Fix a warning for CONFIG_CPUMASK_OFFSTACK

2022-10-26T11:15:37+00:00

commit 16c546e148fa6d14a019431436a6f7b4087dbccd upstream.

When CONFIG_CPUMASK_OFFSTACK and CONFIG_DEBUG_PER_CPU_MAPS is selected,
cpu_max_bits_warn() generates a runtime warning similar as below while
we show /proc/cpuinfo. Fix this by using nr_cpu_ids (the runtime limit)
instead of NR_CPUS to iterate CPUs.

[    3.052463] ------------[ cut here ]------------
[    3.059679] WARNING: CPU: 3 PID: 1 at include/linux/cpumask.h:108 show_cpuinfo+0x5e8/0x5f0
[    3.070072] Modules linked in: efivarfs autofs4
[    3.076257] CPU: 0 PID: 1 Comm: systemd Not tainted 5.19-rc5+ #1052
[    3.099465] Stack : 9000000100157b08 9000000000f18530 9000000000cf846c 9000000100154000
[    3.109127]         9000000100157a50 0000000000000000 9000000100157a58 9000000000ef7430
[    3.118774]         90000001001578e8 0000000000000040 0000000000000020 ffffffffffffffff
[    3.128412]         0000000000aaaaaa 1ab25f00eec96a37 900000010021de80 900000000101c890
[    3.138056]         0000000000000000 0000000000000000 0000000000000000 0000000000aaaaaa
[    3.147711]         ffff8000339dc220 0000000000000001 0000000006ab4000 0000000000000000
[    3.157364]         900000000101c998 0000000000000004 9000000000ef7430 0000000000000000
[    3.167012]         0000000000000009 000000000000006c 0000000000000000 0000000000000000
[    3.176641]         9000000000d3de08 9000000001639390 90000000002086d8 00007ffff0080286
[    3.186260]         00000000000000b0 0000000000000004 0000000000000000 0000000000071c1c
[    3.195868]         ...
[    3.199917] Call Trace:
[    3.203941] [<90000000002086d8>] show_stack+0x38/0x14c
[    3.210666] [<9000000000cf846c>] dump_stack_lvl+0x60/0x88
[    3.217625] [<900000000023d268>] __warn+0xd0/0x100
[    3.223958] [<9000000000cf3c90>] warn_slowpath_fmt+0x7c/0xcc
[    3.231150] [<9000000000210220>] show_cpuinfo+0x5e8/0x5f0
[    3.238080] [<90000000004f578c>] seq_read_iter+0x354/0x4b4
[    3.245098] [<90000000004c2e90>] new_sync_read+0x17c/0x1c4
[    3.252114] [<90000000004c5174>] vfs_read+0x138/0x1d0
[    3.258694] [<90000000004c55f8>] ksys_read+0x70/0x100
[    3.265265] [<9000000000cfde9c>] do_syscall+0x7c/0x94
[    3.271820] [<9000000000202fe4>] handle_syscall+0xc4/0x160
[    3.281824] ---[ end trace 8b484262b4b8c24c ]---

Cc: stable@vger.kernel.org
Signed-off-by: Huacai Chen 
Signed-off-by: Richard Weinberger 
Signed-off-by: Greg Kroah-Hartman

um: Mark all kernel symbols as local

2021-05-22T08:40:34+00:00

[ Upstream commit d5027ca63e0e778b641cf23e3f5c6d6212cf412b ]

Ritesh reported a bug [1] against UML, noting that it crashed on
startup. The backtrace shows the following (heavily redacted):

(gdb) bt
...
 #26 0x0000000060015b5d in sem_init () at ipc/sem.c:268
 #27 0x00007f89906d92f7 in ?? () from /lib/x86_64-linux-gnu/libcom_err.so.2
 #28 0x00007f8990ab8fb2 in call_init (...) at dl-init.c:72
...
 #40 0x00007f89909bf3a6 in nss_load_library (...) at nsswitch.c:359
...
 #44 0x00007f8990895e35 in _nss_compat_getgrnam_r (...) at nss_compat/compat-grp.c:486
 #45 0x00007f8990968b85 in __getgrnam_r [...]
 #46 0x00007f89909d6b77 in grantpt [...]
 #47 0x00007f8990a9394e in __GI_openpty [...]
 #48 0x00000000604a1f65 in openpty_cb (...) at arch/um/os-Linux/sigio.c:407
 #49 0x00000000604a58d0 in start_idle_thread (...) at arch/um/os-Linux/skas/process.c:598
 #50 0x0000000060004a3d in start_uml () at arch/um/kernel/skas/process.c:45
 #51 0x00000000600047b2 in linux_main (...) at arch/um/kernel/um_arch.c:334
 #52 0x000000006000574f in main (...) at arch/um/os-Linux/main.c:144

indicating that the UML function openpty_cb() calls openpty(),
which internally calls __getgrnam_r(), which causes the nsswitch
machinery to get started.

This loads, through lots of indirection that I snipped, the
libcom_err.so.2 library, which (in an unknown function, "??")
calls sem_init().

Now, of course it wants to get libpthread's sem_init(), since
it's linked against libpthread. However, the dynamic linker
looks up that symbol against the binary first, and gets the
kernel's sem_init().

Hajime Tazaki noted that "objcopy -L" can localize a symbol,
so the dynamic linker wouldn't do the lookup this way. I tried,
but for some reason that didn't seem to work.

Doing the same thing in the linker script instead does seem to
work, though I cannot entirely explain - it *also* works if I
just add "VERSION { { global: *; }; }" instead, indicating that
something else is happening that I don't really understand. It
may be that explicitly doing that marks them with some kind of
empty version, and that's different from the default.

Explicitly marking them with a version breaks kallsyms, so that
doesn't seem to be possible.

Marking all the symbols as local seems correct, and does seem
to address the issue, so do that. Also do it for static link,
nsswitch libraries could still be loaded there.

[1] https://bugs.debian.org/983379

Reported-by: Ritesh Raj Sarraf 
Signed-off-by: Johannes Berg 
Acked-By: Anton Ivanov 
Tested-By: Ritesh Raj Sarraf 
Signed-off-by: Richard Weinberger 
Signed-off-by: Sasha Levin

um: change sigio_spinlock to a mutex

2020-11-10T09:23:52+00:00

[ Upstream commit f2d05059e15af3f70502074f4e3a504530af504a ]

Lockdep complains at boot:

=============================
[ BUG: Invalid wait context ]
5.7.0-05093-g46d91ecd597b #98 Not tainted
-----------------------------
swapper/1 is trying to lock:
0000000060931b98 (&desc[i].request_mutex){+.+.}-{3:3}, at: __setup_irq+0x11d/0x623
other info that might help us debug this:
context-{4:4}
1 lock held by swapper/1:
 #0: 000000006074fed8 (sigio_spinlock){+.+.}-{2:2}, at: sigio_lock+0x1a/0x1c
stack backtrace:
CPU: 0 PID: 1 Comm: swapper Not tainted 5.7.0-05093-g46d91ecd597b #98
Stack:
 7fa4fab0 6028dfd1 0000002a 6008bea5
 7fa50700 7fa50040 7fa4fac0 6028e016
 7fa4fb50 6007f6da 60959c18 00000000
Call Trace:
 [<60023a0e>] show_stack+0x13b/0x155
 [<6028e016>] dump_stack+0x2a/0x2c
 [<6007f6da>] __lock_acquire+0x515/0x15f2
 [<6007eb50>] lock_acquire+0x245/0x273
 [<6050d9f1>] __mutex_lock+0xbd/0x325
 [<6050dc76>] mutex_lock_nested+0x1d/0x1f
 [<6008e27e>] __setup_irq+0x11d/0x623
 [<6008e8ed>] request_threaded_irq+0x169/0x1a6
 [<60021eb0>] um_request_irq+0x1ee/0x24b
 [<600234ee>] write_sigio_irq+0x3b/0x76
 [<600383ca>] sigio_broken+0x146/0x2e4
 [<60020bd8>] do_one_initcall+0xde/0x281

Because we hold sigio_spinlock and then get into requesting
an interrupt with a mutex.

Change the spinlock to a mutex to avoid that.

Signed-off-by: Johannes Berg 
Signed-off-by: Richard Weinberger 
Signed-off-by: Sasha Levin

um: Fix FP register size for XSTATE/XSAVE

2019-08-04T07:33:31+00:00

commit 6f602afda7275c24c20ba38b5b6cd4ed08561fff upstream.

Hard code max size. Taken from
https://sourceware.org/git/?p=binutils-gdb.git;a=blob;f=gdb/common/x86-xstate.h

Signed-off-by: Thomas Meyer 
Signed-off-by: Richard Weinberger 
Signed-off-by: Alessio Balsini 
Signed-off-by: Greg Kroah-Hartman

uml: fix a boot splat wrt use of cpu_all_mask

2019-06-22T06:17:14+00:00

[ Upstream commit 689a58605b63173acb0a8cf954af6a8f60440c93 ]

Memory: 509108K/542612K available (3835K kernel code, 919K rwdata, 1028K rodata, 129K init, 211K bss, 33504K reserved, 0K cma-reserved)
NR_IRQS: 15
clocksource: timer: mask: 0xffffffffffffffff max_cycles: 0x1cd42e205, max_idle_ns: 881590404426 ns
------------[ cut here ]------------
WARNING: CPU: 0 PID: 0 at kernel/time/clockevents.c:458 clockevents_register_device+0x72/0x140
posix-timer cpumask == cpu_all_mask, using cpu_possible_mask instead
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 5.1.0-rc4-00048-ged79cc87302b #4
Stack:
 604ebda0 603c5370 604ebe20 6046fd17
 00000000 6006fcbb 604ebdb0 603c53b5
 604ebe10 6003bfc4 604ebdd0 9000001ca
Call Trace:
 [<6006fcbb>] ? printk+0x0/0x94
 [<60083160>] ? clockevents_register_device+0x72/0x140
 [<6001f16e>] show_stack+0x13b/0x155
 [<603c5370>] ? dump_stack_print_info+0xe2/0xeb
 [<6006fcbb>] ? printk+0x0/0x94
 [<603c53b5>] dump_stack+0x2a/0x2c
 [<6003bfc4>] __warn+0x10e/0x13e
 [<60070320>] ? vprintk_func+0xc8/0xcf
 [<60030fd6>] ? block_signals+0x0/0x16
 [<6006fcbb>] ? printk+0x0/0x94
 [<6003c08b>] warn_slowpath_fmt+0x97/0x99
 [<600311a1>] ? set_signals+0x0/0x3f
 [<6003bff4>] ? warn_slowpath_fmt+0x0/0x99
 [<600842cb>] ? tick_oneshot_mode_active+0x44/0x4f
 [<60030fd6>] ? block_signals+0x0/0x16
 [<6006fcbb>] ? printk+0x0/0x94
 [<6007d2d5>] ? __clocksource_select+0x20/0x1b1
 [<60030fd6>] ? block_signals+0x0/0x16
 [<6006fcbb>] ? printk+0x0/0x94
 [<60083160>] clockevents_register_device+0x72/0x140
 [<60031192>] ? get_signals+0x0/0xf
 [<60030fd6>] ? block_signals+0x0/0x16
 [<6006fcbb>] ? printk+0x0/0x94
 [<60002eec>] um_timer_setup+0xc8/0xca
 [<60001b59>] start_kernel+0x47f/0x57e
 [<600035bc>] start_kernel_proc+0x49/0x4d
 [<6006c483>] ? kmsg_dump_register+0x82/0x8a
 [<6001de62>] new_thread_handler+0x81/0xb2
 [<60003571>] ? kmsg_dumper_stdout_init+0x1a/0x1c
 [<60020c75>] uml_finishsetup+0x54/0x59

random: get_random_bytes called from init_oops_id+0x27/0x34 with crng_init=0
---[ end trace 00173d0117a88acb ]---
Calibrating delay loop... 6941.90 BogoMIPS (lpj=34709504)

Signed-off-by: Maciej Żenczykowski 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Cc: Anton Ivanov 
Cc: linux-um@lists.infradead.org
Cc: linux-kernel@vger.kernel.org

Signed-off-by: Richard Weinberger 
Signed-off-by: Sasha Levin

um: Fix to call read_initrd after init_bootmem

2017-05-25T13:44:47+00:00

commit 5b4236e17cc1bd9fa14b2b0c7a4ae632d41f2e20 upstream.

Since read_initrd() invokes alloc_bootmem() for allocating
memory to load initrd image, it must be called after init_bootmem.

This makes read_initrd() called directly from setup_arch()
after init_bootmem() and mem_total_pages().

Fixes: b63236972e1 ("um: Setup physical memory in setup_arch()")
Signed-off-by: Masami Hiramatsu 
Signed-off-by: Richard Weinberger 
Signed-off-by: Greg Kroah-Hartman

nmi_backtrace: generate one-line reports for idle cpus

2016-10-08T01:46:30+00:00

When doing an nmi backtrace of many cores, most of which are idle, the
output is a little overwhelming and very uninformative.  Suppress
messages for cpus that are idling when they are interrupted and just
emit one line, "NMI backtrace for N skipped: idling at pc 0xNNN".

We do this by grouping all the cpuidle code together into a new
.cpuidle.text section, and then checking the address of the interrupted
PC to see if it lies within that section.

This commit suitably tags x86 and tile idle routines, and only adds in
the minimal framework for other architectures.

Link: http://lkml.kernel.org/r/1472487169-14923-5-git-send-email-cmetcalf@mellanox.com
Signed-off-by: Chris Metcalf 
Acked-by: Peter Zijlstra (Intel) 
Tested-by: Peter Zijlstra (Intel) 
Tested-by: Daniel Thompson  [arm]
Tested-by: Petr Mladek 
Cc: Aaron Tomlin 
Cc: Peter Zijlstra (Intel) 
Cc: "Rafael J. Wysocki" 
Cc: Russell King 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

um/ptrace: Fix the syscall number update after a ptrace

2016-09-07T16:25:04+00:00

Update the syscall number after each PTRACE_SETREGS on ORIG_*AX.

This is needed to get the potentially altered syscall number in the
seccomp filters after RET_TRACE.

This fix four seccomp_bpf tests:
> [ RUN      ] TRACE_syscall.skip_after_RET_TRACE
> seccomp_bpf.c:1560:TRACE_syscall.skip_after_RET_TRACE:Expected -1 (18446744073709551615) == syscall(39) (26)
> seccomp_bpf.c:1561:TRACE_syscall.skip_after_RET_TRACE:Expected 1 (1) == (*__errno_location ()) (22)
> [     FAIL ] TRACE_syscall.skip_after_RET_TRACE
> [ RUN      ] TRACE_syscall.kill_after_RET_TRACE
> TRACE_syscall.kill_after_RET_TRACE: Test exited normally instead of by signal (code: 1)
> [     FAIL ] TRACE_syscall.kill_after_RET_TRACE
> [ RUN      ] TRACE_syscall.skip_after_ptrace
> seccomp_bpf.c:1622:TRACE_syscall.skip_after_ptrace:Expected -1 (18446744073709551615) == syscall(39) (26)
> seccomp_bpf.c:1623:TRACE_syscall.skip_after_ptrace:Expected 1 (1) == (*__errno_location ()) (22)
> [     FAIL ] TRACE_syscall.skip_after_ptrace
> [ RUN      ] TRACE_syscall.kill_after_ptrace
> TRACE_syscall.kill_after_ptrace: Test exited normally instead of by signal (code: 1)
> [     FAIL ] TRACE_syscall.kill_after_ptrace

Fixes: 26703c636c1f ("um/ptrace: run seccomp after ptrace")

Signed-off-by: Mickaël Salaün 
Acked-by: Kees Cook 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Cc: James Morris 
Cc: user-mode-linux-devel@lists.sourceforge.net
Signed-off-by: James Morris 
Signed-off-by: Kees Cook

um/ptrace: Fix the syscall_trace_leave call

2016-09-07T16:25:04+00:00

Keep the same semantic as before the commit 26703c636c1f: deallocate
audit context and fake a proper syscall exit.

This fix a kernel panic triggered by the seccomp_bpf test:
> [ RUN      ] global.ERRNO_valid
> BUG: failure at kernel/auditsc.c:1504/__audit_syscall_entry()!
> Kernel panic - not syncing: BUG!

Fixes: 26703c636c1f ("um/ptrace: run seccomp after ptrace")

Signed-off-by: Mickaël Salaün 
Acked-by: Kees Cook 
Cc: Jeff Dike 
Cc: Richard Weinberger 
Cc: James Morris 
Cc: user-mode-linux-devel@lists.sourceforge.net
Signed-off-by: James Morris 
Signed-off-by: Kees Cook

Merge branch 'for-linus-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

2016-08-04T23:37:59+00:00

Pull UML updates from Richard Weinberger:
 "Beside of various fixes this also contains patches to enable features
  such was Kcov, kmemleak and TRACE_IRQFLAGS_SUPPORT on UML"

* 'for-linus-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  hostfs: Freeing an ERR_PTR in hostfs_fill_sb_common()
  um: Support kcov
  um: Enable TRACE_IRQFLAGS_SUPPORT
  um: Use asm-generic/irqflags.h
  um: Fix possible deadlock in sig_handler_common()
  um: Select HAVE_DEBUG_KMEMLEAK
  um: Setup physical memory in setup_arch()
  um: Eliminate null test after alloc_bootmem