Now that the early kernel mapping logic can tolerate placements of
Image that cross swapper table boundaries, we can remove the logic
that adjusts the offset if the dice roll produced an offset that
puts the kernel right on top of one.
Reviewed-by: NSteve Capper <steve.capper@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Mirror arm behaviour for unimplemented syscalls: Below 2048 return
-ENOSYS, above 2048 raise SIGILL.
Signed-off-by: NMichael Weiser <michael.weiser@gmx.de>
[will: Tweak die string to identify as compat syscall]
Signed-off-by: NWill Deacon <will.deacon@arm.com>

do_task_stat() calls get_wchan(), which further does unwind_frame().
unwind_frame() restores frame->pc to original value in case function
graph tracer has modified a return address (LR) in a stack frame to hook
a function return. However, if function graph tracer has hit a filtered
function, then we can't unwind it as ftrace_push_return_trace() has
biased the index(frame->graph) with a 'huge negative'
offset(-FTRACE_NOTRACE_DEPTH).

Moreover, arm64 stack walker defines index(frame->graph) as unsigned
int, which can not compare a -ve number.

Similar problem we can have with calling of walk_stackframe() from
save_stack_trace_tsk() or dump_backtrace().

This patch fixes unwind_frame() to test the index for -ve value and
restore index accordingly before we can restore frame->pc.

Reproducer:

cd /sys/kernel/debug/tracing/
echo schedule > set_graph_notrace
echo 1 > options/display-graph
echo wakeup > current_tracer
ps -ef | grep -i agent

Above commands result in:
Unable to handle kernel paging request at virtual address ffff801bd3d1e000
pgd = ffff8003cbe97c00
[ffff801bd3d1e000] *pgd=0000000000000000, *pud=0000000000000000
Internal error: Oops: 96000006 [#1] SMP
[...]
CPU: 5 PID: 11696 Comm: ps Not tainted 4.11.0+ #33
[...]
task: ffff8003c21ba000 task.stack: ffff8003cc6c0000
PC is at unwind_frame+0x12c/0x180
LR is at get_wchan+0xd4/0x134
pc : [<ffff00000808892c>] lr : [<ffff0000080860b8>] pstate: 60000145
sp : ffff8003cc6c3ab0
x29: ffff8003cc6c3ab0 x28: 0000000000000001
x27: 0000000000000026 x26: 0000000000000026
x25: 00000000000012d8 x24: 0000000000000000
x23: ffff8003c1c04000 x22: ffff000008c83000
x21: ffff8003c1c00000 x20: 000000000000000f
x19: ffff8003c1bc0000 x18: 0000fffffc593690
x17: 0000000000000000 x16: 0000000000000001
x15: 0000b855670e2b60 x14: 0003e97f22cf1d0f
x13: 0000000000000001 x12: 0000000000000000
x11: 00000000e8f4883e x10: 0000000154f47ec8
x9 : 0000000070f367c0 x8 : 0000000000000000
x7 : 00008003f7290000 x6 : 0000000000000018
x5 : 0000000000000000 x4 : ffff8003c1c03cb0
x3 : ffff8003c1c03ca0 x2 : 00000017ffe80000
x1 : ffff8003cc6c3af8 x0 : ffff8003d3e9e000

Process ps (pid: 11696, stack limit = 0xffff8003cc6c0000)
Stack: (0xffff8003cc6c3ab0 to 0xffff8003cc6c4000)
[...]
[<ffff00000808892c>] unwind_frame+0x12c/0x180
[<ffff000008305008>] do_task_stat+0x864/0x870
[<ffff000008305c44>] proc_tgid_stat+0x3c/0x48
[<ffff0000082fde0c>] proc_single_show+0x5c/0xb8
[<ffff0000082b27e0>] seq_read+0x160/0x414
[<ffff000008289e6c>] __vfs_read+0x58/0x164
[<ffff00000828b164>] vfs_read+0x88/0x144
[<ffff00000828c2e8>] SyS_read+0x60/0xc0
[<ffff0000080834a0>] __sys_trace_return+0x0/0x4

Fixes: 20380bb3 (arm64: ftrace: fix a stack tracer's output under function graph tracer)
Signed-off-by: NPratyush Anand <panand@redhat.com>
Signed-off-by: NJerome Marchand <jmarchan@redhat.com>
[catalin.marinas@arm.com: replace WARN_ON with WARN_ON_ONCE]
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Without this fix, /proc/cpuinfo will display an incorrect amount
of CPU cores, after bringing them offline and online again, as
exemplified below:

  $ cat /proc/cpuinfo | grep cores
  cpu cores	: 4
  cpu cores	: 8
  cpu cores	: 8
  cpu cores	: 20
  cpu cores	: 4
  cpu cores	: 3
  cpu cores	: 2
  cpu cores	: 2

This patch fixes this by always zeroing the booted_cores variable
upon turning off a logical CPU.
Tested-by: NDou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: NSamuel Neves <sneves@dei.uc.pt>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: jgross@suse.com
Cc: luto@kernel.org
Cc: prarit@redhat.com
Cc: vkuznets@redhat.com
Link: http://lkml.kernel.org/r/20180221205036.5244-1-sneves@dei.uc.ptSigned-off-by: NIngo Molnar <mingo@kernel.org>

Successful RMW operations are supposed to be fully ordered, but
Alpha's xchg() and cmpxchg() do not meet this requirement.

Will Deacon noticed the bug:

  > So MP using xchg:
  >
  > WRITE_ONCE(x, 1)
  > xchg(y, 1)
  >
  > smp_load_acquire(y) == 1
  > READ_ONCE(x) == 0
  >
  > would be allowed.

... which thus violates the above requirement.

Fix it by adding a leading smp_mb() to the xchg() and cmpxchg() implementations.
Reported-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NAndrea Parri <parri.andrea@gmail.com>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-alpha@vger.kernel.org
Link: http://lkml.kernel.org/r/1519291488-5752-1-git-send-email-parri.andrea@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Replace each occurrence of __ASM__MB with a (trailing) smp_mb() in
xchg(), cmpxchg(), and remove the now unused __ASM__MB definitions;
this improves readability, with no additional synchronization cost.
Suggested-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NAndrea Parri <parri.andrea@gmail.com>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-alpha@vger.kernel.org
Link: http://lkml.kernel.org/r/1519291469-5702-1-git-send-email-parri.andrea@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

x86/intel_rdt: Fix incorrect returned value when creating rdgroup sub-directory in resctrl file system

If no monitoring feature is detected because all monitoring features are
disabled during boot time or there is no monitoring feature in hardware,
creating rdtgroup sub-directory by "mkdir" command reports error:

  mkdir: cannot create directory ‘/sys/fs/resctrl/p1’: No such file or directory

But the sub-directory actually is generated and content is correct:

  cpus  cpus_list  schemata  tasks

The error is because rdtgroup_mkdir_ctrl_mon() returns non zero value after
the sub-directory is created and the returned value is reported as an error
to user.

Clear the returned value to report to user that the sub-directory is
actually created successfully.
Signed-off-by: NWang Hui <john.wanghui@huawei.com>
Signed-off-by: NZhang Yanfei <yanfei.zhang@huawei.com>
Signed-off-by: NFenghua Yu <fenghua.yu@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi V Shankar <ravi.v.shankar@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vikas <vikas.shivappa@intel.com>
Cc: Xiaochen Shen <xiaochen.shen@intel.com>
Link: http://lkml.kernel.org/r/1519356363-133085-1-git-send-email-fenghua.yu@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

When a irq vector is replaced, then the previous vector is normally
released when the first interrupt happens on the new vector. If the target
CPU of the previous vector is already offline when the new vector is
installed, then the previous vector is silently discarded, which leads to
accounting issues causing suspend failures and other problems.

Adjust the logic so that the previous vector is freed in the underlying
matrix allocator to ensure that the accounting stays correct.

Fixes: 69cde000 ("x86/vector: Use matrix allocator for vector assignment")
Reported-by: NYuriy Vostrikov <delamonpansie@gmail.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Tested-by: NYuriy Vostrikov <delamonpansie@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180222112316.930791749@linutronix.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

Some versions of firmware will have a setting that can be configured
to disable the RFI flush, add support for it.

Fixes: 6e032b35 ("powerpc/powernv: Check device-tree for RFI flush settings")
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Some versions of firmware will have a setting that can be configured
to disable the RFI flush, add support for it.

Fixes: 8989d568 ("powerpc/pseries: Query hypervisor for RFI flush settings")
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

Memory addtion and removal by count and indexed-count methods
temporarily mark the LMBs that are being added/removed by a special
flag value DRMEM_LMB_RESERVED. Accessing flags value directly at a few
places without proper accessor method is causing two unexpected
side-effects:

- DRMEM_LMB_RESERVED bit is becoming part of the flags word of
  drconf_cell_v2 entries in ibm,dynamic-memory-v2 DT property.
- This results in extra drconf_cell entries in ibm,dynamic-memory-v2.
  For example if 1G memory is added, it leads to one entry for 3 LMBs
  and 1 separate entry for the last LMB. All the 4 LMBs should be
  defined by one entry here.

Fix this by always accessing the flags by its accessor method
drmem_lmb_flags().

Fixes: 2b31e3ae ("powerpc/drmem: Add support for ibm, dynamic-memory-v2 property")
Signed-off-by: NBharata B Rao <bharata@linux.vnet.ibm.com>
Reviewed-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The MIPS %.its.S compiler command did not define __ASSEMBLY__, which meant
when compiler_types.h was added to kconfig.h, unexpected things appeared
(e.g. struct declarations) which should not have been present. As done in
the general %.S compiler command, __ASSEMBLY__ is now included here too.

The failure was:

    Error: arch/mips/boot/vmlinux.gz.its:201.1-2 syntax error
    FATAL ERROR: Unable to parse input tree
    /usr/bin/mkimage: Can't read arch/mips/boot/vmlinux.gz.itb.tmp: Invalid argument
    /usr/bin/mkimage Can't add hashes to FIT blob
Reported-by: Nkbuild test robot <lkp@intel.com>
Fixes: 28128c61 ("kconfig.h: Include compiler types to avoid missed struct attributes")
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I recently noticed a crash on arm64 when feeding a bogus index
into BPF tail call helper. The crash would not occur when the
interpreter is used, but only in case of JIT. Output looks as
follows:

  [  347.007486] Unable to handle kernel paging request at virtual address fffb850e96492510
  [...]
  [  347.043065] [fffb850e96492510] address between user and kernel address ranges
  [  347.050205] Internal error: Oops: 96000004 [#1] SMP
  [...]
  [  347.190829] x13: 0000000000000000 x12: 0000000000000000
  [  347.196128] x11: fffc047ebe782800 x10: ffff808fd7d0fd10
  [  347.201427] x9 : 0000000000000000 x8 : 0000000000000000
  [  347.206726] x7 : 0000000000000000 x6 : 001c991738000000
  [  347.212025] x5 : 0000000000000018 x4 : 000000000000ba5a
  [  347.217325] x3 : 00000000000329c4 x2 : ffff808fd7cf0500
  [  347.222625] x1 : ffff808fd7d0fc00 x0 : ffff808fd7cf0500
  [  347.227926] Process test_verifier (pid: 4548, stack limit = 0x000000007467fa61)
  [  347.235221] Call trace:
  [  347.237656]  0xffff000002f3a4fc
  [  347.240784]  bpf_test_run+0x78/0xf8
  [  347.244260]  bpf_prog_test_run_skb+0x148/0x230
  [  347.248694]  SyS_bpf+0x77c/0x1110
  [  347.251999]  el0_svc_naked+0x30/0x34
  [  347.255564] Code: 9100075a d280220a 8b0a002a d37df04b (f86b694b)
  [...]

In this case the index used in BPF r3 is the same as in r1
at the time of the call, meaning we fed a pointer as index;
here, it had the value 0xffff808fd7cf0500 which sits in x2.

While I found tail calls to be working in general (also for
hitting the error cases), I noticed the following in the code
emission:

  # bpftool p d j i 988
  [...]
  38:   ldr     w10, [x1,x10]
  3c:   cmp     w2, w10
  40:   b.ge    0x000000000000007c              <-- signed cmp
  44:   mov     x10, #0x20                      // #32
  48:   cmp     x26, x10
  4c:   b.gt    0x000000000000007c
  50:   add     x26, x26, #0x1
  54:   mov     x10, #0x110                     // #272
  58:   add     x10, x1, x10
  5c:   lsl     x11, x2, #3
  60:   ldr     x11, [x10,x11]                  <-- faulting insn (f86b694b)
  64:   cbz     x11, 0x000000000000007c
  [...]

Meaning, the tests passed because commit ddb55992 ("arm64:
bpf: implement bpf_tail_call() helper") was using signed compares
instead of unsigned which as a result had the test wrongly passing.

Change this but also the tail call count test both into unsigned
and cap the index as u32. Latter we did as well in 90caccdd
("bpf: fix bpf_tail_call() x64 JIT") and is needed in addition here,
too. Tested on HiSilicon Hi1616.

Result after patch:

  # bpftool p d j i 268
  [...]
  38:	ldr	w10, [x1,x10]
  3c:	add	w2, w2, #0x0
  40:	cmp	w2, w10
  44:	b.cs	0x0000000000000080
  48:	mov	x10, #0x20                  	// #32
  4c:	cmp	x26, x10
  50:	b.hi	0x0000000000000080
  54:	add	x26, x26, #0x1
  58:	mov	x10, #0x110                 	// #272
  5c:	add	x10, x1, x10
  60:	lsl	x11, x2, #3
  64:	ldr	x11, [x10,x11]
  68:	cbz	x11, 0x0000000000000080
  [...]

Fixes: ddb55992 ("arm64: bpf: implement bpf_tail_call() helper")
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

Implement a retpoline [0] for the BPF tail call JIT'ing that converts
the indirect jump via jmp %rax that is used to make the long jump into
another JITed BPF image. Since this is subject to speculative execution,
we need to control the transient instruction sequence here as well
when CONFIG_RETPOLINE is set, and direct it into a pause + lfence loop.
The latter aligns also with what gcc / clang emits (e.g. [1]).

JIT dump after patch:

  # bpftool p d x i 1
   0: (18) r2 = map[id:1]
   2: (b7) r3 = 0
   3: (85) call bpf_tail_call#12
   4: (b7) r0 = 2
   5: (95) exit

With CONFIG_RETPOLINE:

  # bpftool p d j i 1
  [...]
  33:	cmp    %edx,0x24(%rsi)
  36:	jbe    0x0000000000000072  |*
  38:	mov    0x24(%rbp),%eax
  3e:	cmp    $0x20,%eax
  41:	ja     0x0000000000000072  |
  43:	add    $0x1,%eax
  46:	mov    %eax,0x24(%rbp)
  4c:	mov    0x90(%rsi,%rdx,8),%rax
  54:	test   %rax,%rax
  57:	je     0x0000000000000072  |
  59:	mov    0x28(%rax),%rax
  5d:	add    $0x25,%rax
  61:	callq  0x000000000000006d  |+
  66:	pause                      |
  68:	lfence                     |
  6b:	jmp    0x0000000000000066  |
  6d:	mov    %rax,(%rsp)         |
  71:	retq                       |
  72:	mov    $0x2,%eax
  [...]

  * relative fall-through jumps in error case
  + retpoline for indirect jump

Without CONFIG_RETPOLINE:

  # bpftool p d j i 1
  [...]
  33:	cmp    %edx,0x24(%rsi)
  36:	jbe    0x0000000000000063  |*
  38:	mov    0x24(%rbp),%eax
  3e:	cmp    $0x20,%eax
  41:	ja     0x0000000000000063  |
  43:	add    $0x1,%eax
  46:	mov    %eax,0x24(%rbp)
  4c:	mov    0x90(%rsi,%rdx,8),%rax
  54:	test   %rax,%rax
  57:	je     0x0000000000000063  |
  59:	mov    0x28(%rax),%rax
  5d:	add    $0x25,%rax
  61:	jmpq   *%rax               |-
  63:	mov    $0x2,%eax
  [...]

  * relative fall-through jumps in error case
  - plain indirect jump as before

  [0] https://support.google.com/faqs/answer/7625886
  [1] https://github.com/gcc-mirror/gcc/commit/a31e654fa107be968b802786d747e962c2fcdb2bSigned-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>

On i386, there are 2 types of PLTs, PIC and non-PIC.  PIE and shared
objects must use PIC PLT.  To use PIC PLT, you need to load
_GLOBAL_OFFSET_TABLE_ into EBX first.  There is no need for that on
x86-64 since x86-64 uses PC-relative PLT.

On x86-64, for 32-bit PC-relative branches, we can generate PLT32
relocation, instead of PC32 relocation, which can also be used as
a marker for 32-bit PC-relative branches.  Linker can always reduce
PLT32 relocation to PC32 if function is defined locally.   Local
functions should use PC32 relocation.  As far as Linux kernel is
concerned, R_X86_64_PLT32 can be treated the same as R_X86_64_PC32
since Linux kernel doesn't use PLT.

R_X86_64_PLT32 for 32-bit PC-relative branches has been enabled in
binutils master branch which will become binutils 2.31.

[ hjl is working on having better documentation on this all, but a few
  more notes from him:

   "PLT32 relocation is used as marker for PC-relative branches. Because
    of EBX, it looks odd to generate PLT32 relocation on i386 when EBX
    doesn't have GOT.

    As for symbol resolution, PLT32 and PC32 relocations are almost
    interchangeable. But when linker sees PLT32 relocation against a
    protected symbol, it can resolved locally at link-time since it is
    used on a branch instruction. Linker can't do that for PC32
    relocation"

  but for the kernel use, the two are basically the same, and this
  commit gets things building and working with the current binutils
  master   - Linus ]
Signed-off-by: NH.J. Lu <hjl.tools@gmail.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ioremap_page_range doesn't honour break-before-make and attempts to put
down huge mappings (using p*d_set_huge) over the top of pre-existing
table entries. This leads to us leaking page table memory and also gives
rise to TLB conflicts and spurious aborts, which have been seen in
practice on Cortex-A75.

Until this has been resolved, refuse to put block mappings when the
existing entry is found to be present.

Fixes: 324420bf ("arm64: add support for ioremap() block mappings")
Reported-by: NHanjun Guo <hanjun.guo@linaro.org>
Reported-by: NLei Li <lious.lilei@hisilicon.com>
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

On lkml suggestions were made to split up such trivial typo fixes into per subsystem
patches:

  --- a/arch/x86/boot/compressed/eboot.c
  +++ b/arch/x86/boot/compressed/eboot.c
  @@ -439,7 +439,7 @@ setup_uga32(void **uga_handle, unsigned long size, u32 *width, u32 *height)
          struct efi_uga_draw_protocol *uga = NULL, *first_uga;
          efi_guid_t uga_proto = EFI_UGA_PROTOCOL_GUID;
          unsigned long nr_ugas;
  -       u32 *handles = (u32 *)uga_handle;;
  +       u32 *handles = (u32 *)uga_handle;
          efi_status_t status = EFI_INVALID_PARAMETER;
          int i;

This patch is the result of the following script:

  $ sed -i 's/;;$/;/g' $(git grep -E ';;$'  | grep "\.[ch]:"  | grep -vwE 'for|ia64' | cut -d: -f1 | sort | uniq)

... followed by manual review to make sure it's all good.

Splitting this up is just crazy talk, let's get over with this and just do it.
Reported-by: NPavel Machek <pavel@ucw.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

I am using SECCOMP to filter syscalls on a ppc32 platform, and noticed
that the JIT compiler was failing on the BPF even though the
interpreter was working fine.

The issue was that the compiler was missing one of the instructions
used by SECCOMP, so here is a patch to enable JIT for that
instruction.

Fixes: eb84bab0 ("ppc: Kconfig: Enable BPF JIT on ppc32")
Signed-off-by: NMark Lord <mlord@pobox.com>
Acked-by: NNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

This reverts commit 02ef6dd8.

The earlier patch tried to enable support for a new property
"ibm,drc-info" on powerpc systems.

Unfortunately, some errors in the associated patch set break things
in some of the DLPAR operations.  In particular when attempting to
hot-add a new CPU or set of CPUs, the original patch failed to
properly calculate the available resources, and aborted the operation.
In addition, the original set missed several opportunities to compress
and reuse common code.

As the associated patch set was meant to provide an optimization of
storage and performance of a set of device-tree properties for future
systems with large amounts of resources, reverting just restores
the previous behavior for existing systems.  It seems unnecessary
to enable this feature and introduce the consequent problems in the
field that it will cause at this time, so please revert it for now
until testing of the corrections are finished properly.

Fixes: 02ef6dd8 ("powerpc: Enable support for ibm,drc-info devtree property")
Signed-off-by: NMichael W. Bringmann <mwb@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

We had a mid-air collision between two new firmware features, DRMEM_V2
and DRC_INFO, and they ended up with the same value.

No one's actually reported any problems, presumably because the new
firmware that supports both properties is not widely available, and
the two properties tend to be enabled together.

Still if we ever had one enabled but not the other, the bugs that
could result are many and varied. So fix it.

Fixes: 3f38000e ("powerpc/firmware: Add definitions for new drc-info firmware feature")
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: NTyrel Datwyler <tyreld@linux.vnet.ibm.com>

Looking at functions with large stack frames across all architectures
led me discovering that BUG() suffers from the same problem as
fortify_panic(), which I've added a workaround for already.

In short, variables that go out of scope by calling a noreturn function
or __builtin_unreachable() keep using stack space in functions
afterwards.

A workaround that was identified is to insert an empty assembler
statement just before calling the function that doesn't return.  I'm
adding a macro "barrier_before_unreachable()" to document this, and
insert calls to that in all instances of BUG() that currently suffer
from this problem.

The files that saw the largest change from this had these frame sizes
before, and much less with my patch:

  fs/ext4/inode.c:82:1: warning: the frame size of 1672 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/namei.c:434:1: warning: the frame size of 904 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/super.c:2279:1: warning: the frame size of 1160 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/ext4/xattr.c:146:1: warning: the frame size of 1168 bytes is larger than 800 bytes [-Wframe-larger-than=]
  fs/f2fs/inode.c:152:1: warning: the frame size of 1424 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_core.c:1195:1: warning: the frame size of 1068 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_core.c:395:1: warning: the frame size of 1084 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_ftp.c:298:1: warning: the frame size of 928 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_ftp.c:418:1: warning: the frame size of 908 bytes is larger than 800 bytes [-Wframe-larger-than=]
  net/netfilter/ipvs/ip_vs_lblcr.c:718:1: warning: the frame size of 960 bytes is larger than 800 bytes [-Wframe-larger-than=]
  drivers/net/xen-netback/netback.c:1500:1: warning: the frame size of 1088 bytes is larger than 800 bytes [-Wframe-larger-than=]

In case of ARC and CRIS, it turns out that the BUG() implementation
actually does return (or at least the compiler thinks it does),
resulting in lots of warnings about uninitialized variable use and
leaving noreturn functions, such as:

  block/cfq-iosched.c: In function 'cfq_async_queue_prio':
  block/cfq-iosched.c:3804:1: error: control reaches end of non-void function [-Werror=return-type]
  include/linux/dmaengine.h: In function 'dma_maxpq':
  include/linux/dmaengine.h:1123:1: error: control reaches end of non-void function [-Werror=return-type]

This makes them call __builtin_trap() instead, which should normally
dump the stack and kill the current process, like some of the other
architectures already do.

I tried adding barrier_before_unreachable() to panic() and
fortify_panic() as well, but that had very little effect, so I'm not
submitting that patch.

Vineet said:

: For ARC, it is double win.
:
: 1. Fixes 3 -Wreturn-type warnings
:
: | ../net/core/ethtool.c:311:1: warning: control reaches end of non-void function
: [-Wreturn-type]
: | ../kernel/sched/core.c:3246:1: warning: control reaches end of non-void function
: [-Wreturn-type]
: | ../include/linux/sunrpc/svc_xprt.h:180:1: warning: control reaches end of
: non-void function [-Wreturn-type]
:
: 2.  bloat-o-meter reports code size improvements as gcc elides the
:    generated code for stack return.

Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
Link: http://lkml.kernel.org/r/20171219114112.939391-1-arnd@arndb.deSigned-off-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: Vineet Gupta <vgupta@synopsys.com>	[arch/arc]
Tested-by: Vineet Gupta <vgupta@synopsys.com>	[arch/arc]
Cc: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christopher Li <sparse@chrisli.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Continuing along with the fight against smp_read_barrier_depends() [1]
(or rather, against its improper use), add an unconditional barrier to
cmpxchg.  This guarantees that dependency ordering is preserved when a
dependency is headed by an unsuccessful cmpxchg.  As it turns out, the
change could enable further simplification of LKMM as proposed in [2].

[1] https://marc.info/?l=linux-kernel&m=150884953419377&w=2
    https://marc.info/?l=linux-kernel&m=150884946319353&w=2
    https://marc.info/?l=linux-kernel&m=151215810824468&w=2
    https://marc.info/?l=linux-kernel&m=151215816324484&w=2

[2] https://marc.info/?l=linux-kernel&m=151881978314872&w=2Signed-off-by: NAndrea Parri <parri.andrea@gmail.com>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Acked-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-alpha@vger.kernel.org
Link: http://lkml.kernel.org/r/1519152356-4804-1-git-send-email-parri.andrea@gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

GCC-8 shows a warning for the x86 oprofile code that copies per-CPU
data from CPU 0 to all other CPUs, which when building a non-SMP
kernel turns into a memcpy() with identical source and destination
pointers:

 arch/x86/oprofile/nmi_int.c: In function 'mux_clone':
 arch/x86/oprofile/nmi_int.c:285:2: error: 'memcpy' source argument is the same as destination [-Werror=restrict]
   memcpy(per_cpu(cpu_msrs, cpu).multiplex,
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          per_cpu(cpu_msrs, 0).multiplex,
          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          sizeof(struct op_msr) * model->num_virt_counters);
          ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 arch/x86/oprofile/nmi_int.c: In function 'nmi_setup':
 arch/x86/oprofile/nmi_int.c:466:3: error: 'memcpy' source argument is the same as destination [-Werror=restrict]
 arch/x86/oprofile/nmi_int.c:470:3: error: 'memcpy' source argument is the same as destination [-Werror=restrict]

I have analyzed a number of such warnings now: some are valid and the
GCC warning is welcome. Others turned out to be false-positives, and
GCC was changed to not warn about those any more. This is a corner case
that is a false-positive but the GCC developers feel it's better to keep
warning about it.

In this case, it seems best to work around it by telling GCC
a little more clearly that this code path is never hit with
an IS_ENABLED() configuration check.

Cc:stable as we also want old kernels to build cleanly with GCC-8.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Sebor <msebor@gcc.gnu.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: oprofile-list@lists.sf.net
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20180220205826.2008875-1-arnd@arndb.de
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84095Signed-off-by: NIngo Molnar <mingo@kernel.org>

The notify_resume() callback in eeh_ops is NULL on powernv, leading to
crashes:

  NIP (null)
  LR  eeh_report_resume+0x218/0x220
  Call Trace:
   eeh_report_resume+0x1f0/0x220 (unreliable)
   eeh_pe_dev_traverse+0x98/0x170
   eeh_handle_normal_event+0x3f4/0x650
   eeh_handle_event+0x54/0x380
   eeh_event_handler+0x14c/0x210
   kthread+0x168/0x1b0
   ret_from_kernel_thread+0x5c/0xb4

Fix it by adding a check before calling it.

Fixes: 856e1eb9 ("PCI/AER: Add uevents in AER and EEH error/resume")
Signed-off-by: NJuan J. Alvarez <jjalvare@linux.vnet.ibm.com>
Reviewed-by: NBryant G. Ly <bryantly@linux.vnet.ibm.com>
Tested-by: NCarol L. Soto <clsoto@us.ibm.com>
Reviewed-by: NAndrew Donnellan <andrew.donnellan@au1.ibm.com>
Tested-by: NMauro S. M. Rodrigues <maurosr@linux.vnet.ibm.com>
Acked-by: NMichael Neuling <mikey@neuling.org>
[mpe: Rewrite change log]
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

The sbi_ prefix would seem to indicate an SBI interface, and save is not
very specific. After applying this patch, reading head.S makes more sense.
Signed-off-by: NMichael Clark <michaeljclark@mac.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

Interrupt is allowed during exception handling.
There are warning messages if the kernel enables the configuration
'CONFIG_DEBUG_ATOMIC_SLEEP=y'.

BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:23
in_atomic(): 0, irqs_disabled(): 1, pid: 43, name: ash
CPU: 0 PID: 43 Comm: ash Tainted:  G	 W	 4.15.0-rc8-00089-g89ffdae-dirty #17
Call Trace:
[<000000009abb1587>] walk_stackframe+0x0/0x7a
[<00000000d4f3d088>] ___might_sleep+0x102/0x11a
[<00000000b1fd792a>] down_read+0x18/0x28
[<000000000289ec01>] do_page_fault+0x86/0x2f6
[<00000000012441f6>] _do_fork+0x1b4/0x1e0
[<00000000f46c3e3b>] ret_from_syscall+0xa/0xe
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NZong Li <zong@andestech.com>
Signed-off-by: NPalmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

The ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE symbol was removed in
commit 51a02124 ("atomic64: no need for
CONFIG_ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE").

Remove the ARCH_HAS_ATOMIC64_DEC_IS_POSITIVE select from RISCV.

Discovered with the
https://github.com/ulfalizer/Kconfiglib/blob/master/examples/list_undefined.py
script.
Signed-off-by: NUlf Magnusson <ulfalizer@gmail.com>
Reviewed-by: NJonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

The RISCV_IRQ_INTC configuration symbol is undefined, but RISCV selects
it. Quoting Palmer Dabbelt:

	It looks like this slipped through, the symbol has been renamed
	RISCV_INTC.

No RISCV_INTC configuration symbol has been merged either. Just remove
the RISCV_IRQ_INTC select for now.
Signed-off-by: NUlf Magnusson <ulfalizer@gmail.com>
Signed-off-by: NPalmer Dabbelt <palmer@sifive.com>

The ARCH_WANT_OPTIONAL_GPIOLIB symbol was removed in commit 65053e1a
("gpio: delete ARCH_[WANTS_OPTIONAL|REQUIRE]_GPIOLIB"). GPIOLIB should
just be selected explicitly if needed.

Remove the ARCH_WANT_OPTIONAL_GPIOLIB select from RISCV.

See commit 0145071b ("x86: Do away with
ARCH_[WANT_OPTIONAL|REQUIRE]_GPIOLIB") and commit da9a1c67 ("arm64: do
away with ARCH_[WANT_OPTIONAL|REQUIRE]_GPIOLIB") as well.

Discovered with the
https://github.com/ulfalizer/Kconfiglib/blob/master/examples/list_undefined.py
script.
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NUlf Magnusson <ulfalizer@gmail.com>
Signed-off-by: NPalmer Dabbelt <palmer@dabbelt.com>

MIPS' struct compat_flock doesn't match the 32-bit struct flock, as it
has an extra short __unused before pad[4], which combined with alignment
increases the size to 40 bytes compared with struct flock's 36 bytes.

Since commit 8c6657cb ("Switch flock copyin/copyout primitives to
copy_{from,to}_user()"), put_compat_flock() writes the full compat_flock
struct to userland, which results in corruption of the userland word
after the struct flock when running 32-bit userlands on 64-bit kernels.

This was observed to cause a bus error exception when starting Firefox
on Debian 8 (Jessie).
Reported-by: NPeter Mamonov <pmamonov@gmail.com>
Signed-off-by: NJames Hogan <jhogan@kernel.org>
Tested-by: NPeter Mamonov <pmamonov@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.13+
Patchwork: https://patchwork.linux-mips.org/patch/18646/

The ID_AA64DFR0_EL1.PMUVer field doesn't follow the usual ID registers
scheme. While value 0xf indicates a non-architected PMU is implemented,
values 0x1 to 0xe indicate an increasingly featureful architected PMU,
as if the field were unsigned.

For more details, see ARM DDI 0487C.a, D10.1.4, "Alternative ID scheme
used for the Performance Monitors Extension version".

Currently, we treat the field as signed, and erroneously bail out for
values 0x8 to 0xe. Let's correct that.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

The ux500 PMU IRQ bouncer is getting in the way of some fundametnal
changes to the ARM PMU driver, and it's the only special case that
exists today. Let's remove it.
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

... since u64 has a hidden header dependency that was not there before
using it (i.e. it breaks our VMM build).

Also, __u64 is the right way to expose data types through UAPI.
Signed-off-by: NKarimAllah Ahmed <karahmed@amazon.de>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: devel@linuxdriverproject.org
Fixes: 93286261 ("x86/hyperv: Reenlightenment notifications support")
Link: http://lkml.kernel.org/r/1519112391-23773-1-git-send-email-karahmed@amazon.deSigned-off-by: NIngo Molnar <mingo@kernel.org>

__show_regs pretty prints PC and LR by attempting to map them to kernel
function names to improve the utility of crash reports. Unfortunately,
this mapping is applied even when the pt_regs corresponds to user mode,
resulting in a KASLR oracle.

Avoid this issue by only looking up the function symbols when the register
state indicates that we're actually running at EL1.

Cc: <stable@vger.kernel.org>
Reported-by: NNCSC Security <security@ncsc.gov.uk>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Stop printing a (ratelimited) kernel message for each instance of an
unimplemented syscall being called. Userland making an unimplemented
syscall is not necessarily misbehaviour and to be expected with a
current userland running on an older kernel. Also, the current message
looks scary to users but does not actually indicate a real problem nor
help them narrow down the cause. Just rely on sys_ni_syscall() to return
-ENOSYS.

Cc: <stable@vger.kernel.org>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NMichael Weiser <michael.weiser@gmx.de>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

aarch64 unhandled signal kernel messages are very verbose, suggesting
them to be more of a debugging aid:

sigsegv[33]: unhandled level 2 translation fault (11) at 0x00000000, esr
0x92000046, in sigsegv[400000+71000]
CPU: 1 PID: 33 Comm: sigsegv Tainted: G        W        4.15.0-rc3+ #3
Hardware name: linux,dummy-virt (DT)
pstate: 60000000 (nZCv daif -PAN -UAO)
pc : 0x4003f4
lr : 0x4006bc
sp : 0000fffffe94a060
x29: 0000fffffe94a070 x28: 0000000000000000
x27: 0000000000000000 x26: 0000000000000000
x25: 0000000000000000 x24: 00000000004001b0
x23: 0000000000486ac8 x22: 00000000004001c8
x21: 0000000000000000 x20: 0000000000400be8
x19: 0000000000400b30 x18: 0000000000484728
x17: 000000000865ffc8 x16: 000000000000270f
x15: 00000000000000b0 x14: 0000000000000002
x13: 0000000000000001 x12: 0000000000000000
x11: 0000000000000000 x10: 0008000020008008
x9 : 000000000000000f x8 : ffffffffffffffff
x7 : 0004000000000000 x6 : ffffffffffffffff
x5 : 0000000000000000 x4 : 0000000000000000
x3 : 00000000004003e4 x2 : 0000fffffe94a1e8
x1 : 000000000000000a x0 : 0000000000000000

Disable them by default, so they can be enabled using
/proc/sys/debug/exception-trace.

Cc: <stable@vger.kernel.org>
Signed-off-by: NMichael Weiser <michael.weiser@gmx.de>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

Our field definitions for CTR_EL0 suffer from a number of problems:

  - The IDC and DIC fields are missing, which causes us to enable CTR
    trapping on CPUs with either of these returning non-zero values.

  - The ERG is FTR_LOWER_SAFE, whereas it should be treated like CWG as
    FTR_HIGHER_SAFE so that applications can use it to avoid false sharing.

  - [nit] A RES1 field is described as "RAO"

This patch updates the CTR_EL0 field definitions to fix these issues.

Cc: <stable@vger.kernel.org>
Cc: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

In converting __range_ok() into a static inline, I inadvertently made
it more type-safe, but without considering the ordering of the relevant
conversions. This leads to quite a lot of Sparse noise about the fact
that we use __chk_user_ptr() after addr has already been converted from
a user pointer to an unsigned long.

Rather than just adding another cast for the sake of shutting Sparse up,
it seems reasonable to rework the types to make logical sense (although
the resulting codegen for __range_ok() remains identical). The only
callers this affects directly are our compat traps where the inferred
"user-pointer-ness" of a register value now warrants explicit casting.
Signed-off-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Since commit e1a50de3 (arm64: cputype: Silence Sparse warnings),
compilation of arm64 architecture is broken with the following error
messages:

  AR      arch/arm64/kernel/built-in.o
  arch/arm64/kernel/head.S: Assembler messages:
  arch/arm64/kernel/head.S:677: Error: found 'L', expected: ')'
  arch/arm64/kernel/head.S:677: Error: found 'L', expected: ')'
  arch/arm64/kernel/head.S:677: Error: found 'L', expected: ')'
  arch/arm64/kernel/head.S:677: Error: junk at end of line, first
  unrecognized character is `L'
  arch/arm64/kernel/head.S:677: Error: unexpected characters following
  instruction at operand 2 -- `movz x1,:abs_g1_s:0xff00ffffffUL'
  arch/arm64/kernel/head.S:677: Error: unexpected characters following
  instruction at operand 2 -- `movk x1,:abs_g0_nc:0xff00ffffffUL'

This patch fixes the same by using the UL() macro correctly for
assigning the MPIDR_HWID_BITMASK macro value.

Fixes: e1a50de3 ("arm64: cputype: Silence Sparse warnings")
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NBhupesh Sharma <bhsharma@redhat.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

The kernel panics on PV domains because native_smp_cpus_done() is
only called for HVM domains.

Calculate __max_logical_packages for PV domains.

Fixes: b4c0a732 ("x86/smpboot: Fix __max_logical_packages estimate")
Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
Tested-and-reported-by: NSimon Gaiser <simon@invisiblethingslab.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: xen-devel@lists.xenproject.org
Reviewed-by: NBoris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: NJuergen Gross <jgross@suse.com>