commit 8f7baad7f03543451af27f5380fc816b008aa1f2 upstream

Neal Cardwell mentioned that snd_wnd would be useful for diagnosing TCP
performance problems --
> (1) Usually when we're diagnosing TCP performance problems, we do so
> from the sender, since the sender makes most of the
> performance-critical decisions (cwnd, pacing, TSO size, TSQ, etc).
> From the sender-side the thing that would be most useful is to see
> tp->snd_wnd, the receive window that the receiver has advertised to
> the sender.

This serves the purpose of adding an additional __u32 to avoid the
would-be hole caused by the addition of the tcpi_rcvi_ooopack field.
Signed-off-by: NThomas Higdon <tph@fb.com>
Acked-by: NYuchung Cheng <ycheng@google.com>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Acked-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NTony Lu <tonylu@linux.alibaba.com>
Acked-by: NDust Li <dust.li@linux.alibaba.com>

commit f9af2dbbfe01def62765a58af7fbc488351893c3 upstream

For receive-heavy cases on the server-side, we want to track the
connection quality for individual client IPs. This counter, similar to
the existing system-wide TCPOFOQueue counter in /proc/net/netstat,
tracks out-of-order packet reception. By providing this counter in
TCP_INFO, it will allow understanding to what degree receive-heavy
sockets are experiencing out-of-order delivery and packet drops
indicating congestion.

Please note that this is similar to the counter in NetBSD TCP_INFO, and
has the same name.

Also note that we avoid increasing the size of the tcp_sock struct by
taking advantage of a hole.
Signed-off-by: NThomas Higdon <tph@fb.com>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NTony Lu <tonylu@linux.alibaba.com>
Acked-by: NDust Li <dust.li@linux.alibaba.com>

Export "memory.min" and "memory.low" from cgroup v2 to v1.

There is a subtle difference between v1 and v2, i.e. no task is allowed
in intermediate memcgs under v2 hierarchy and this can make a different
behaviour for them, it requires all the intermediate nodes having the
memory.min|low set, we must keep this in mind when using this feature
under v1.
Signed-off-by: NXu Yu <xuyu@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>

Export "memory.events" and "memory.events.local" from cgroup v2 to v1.
Signed-off-by: NXu Yu <xuyu@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>

commit 7a1adfddaf0d11a39fdcaf6e82a88e9c0586e08b upstream.

It was reported that on some of our machines containers were restarted
with OOM symptoms without an obvious reason.  Despite there were almost no
memory pressure and plenty of page cache, MEMCG_OOM event was raised
occasionally, causing the container management software to think, that OOM
has happened.  However, no tasks have been killed.

The following investigation showed that the problem is caused by a failing
attempt to charge a high-order page.  In such case, the OOM killer is
never invoked.  As shown below, it can happen under conditions, which are
very far from a real OOM: e.g.  there is plenty of clean page cache and no
memory pressure.

There is no sense in raising an OOM event in this case, as it might
confuse a user and lead to wrong and excessive actions (e.g.  restart the
workload, as in my case).

Let's look at the charging path in try_charge().  If the memory usage is
about memory.max, which is absolutely natural for most memory cgroups, we
try to reclaim some pages.  Even if we were able to reclaim enough memory
for the allocation, the following check can fail due to a race with
another concurrent allocation:

    if (mem_cgroup_margin(mem_over_limit) >= nr_pages)
        goto retry;

For regular pages the following condition will save us from triggering
the OOM:

   if (nr_reclaimed && nr_pages <= (1 << PAGE_ALLOC_COSTLY_ORDER))
       goto retry;

But for high-order allocation this condition will intentionally fail.  The
reason behind is that we'll likely fall to regular pages anyway, so it's
ok and even preferred to return ENOMEM.

In this case the idea of raising MEMCG_OOM looks dubious.

Fix this by moving MEMCG_OOM raising to mem_cgroup_oom() after allocation
order check, so that the event won't be raised for high order allocations.
This change doesn't affect regular pages allocation and charging.

Link: http://lkml.kernel.org/r/20181004214050.7417-1-guro@fb.comSigned-off-by: NRoman Gushchin <guro@fb.com>
Acked-by: NDavid Rientjes <rientjes@google.com>
Acked-by: NMichal Hocko <mhocko@kernel.org>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NXu Yu <xuyu@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>

commit 1e577f970f66a53d429cbee37b36177c9712f488 upstream.

The memory controller in cgroup v2 exposes memory.events file for each
memcg which shows the number of times events like low, high, max, oom
and oom_kill have happened for the whole tree rooted at that memcg.
Users can also poll or register notification to monitor the changes in
that file.  Any event at any level of the tree rooted at memcg will
notify all the listeners along the path till root_mem_cgroup.  There are
existing users which depend on this behavior.

However there are users which are only interested in the events
happening at a specific level of the memcg tree and not in the events in
the underlying tree rooted at that memcg.  One such use-case is a
centralized resource monitor which can dynamically adjust the limits of
the jobs running on a system.  The jobs can create their sub-hierarchy
for their own sub-tasks.  The centralized monitor is only interested in
the events at the top level memcgs of the jobs as it can then act and
adjust the limits of the jobs.  Using the current memory.events for such
centralized monitor is very inconvenient.  The monitor will keep
receiving events which it is not interested and to find if the received
event is interesting, it has to read memory.event files of the next
level and compare it with the top level one.  So, let's introduce
memory.events.local to the memcg which shows and notify for the events
at the memcg level.

Now, does memory.stat and memory.pressure need their local versions.  IMHO
no due to the no internal process contraint of the cgroup v2.  The
memory.stat file of the top level memcg of a job shows the stats and
vmevents of the whole tree.  The local stats or vmevents of the top level
memcg will only change if there is a process running in that memcg but v2
does not allow that.  Similarly for memory.pressure there will not be any
process in the internal nodes and thus no chance of local pressure.

Link: http://lkml.kernel.org/r/20190527174643.209172-1-shakeelb@google.comSigned-off-by: NShakeel Butt <shakeelb@google.com>
Reviewed-by: NRoman Gushchin <guro@fb.com>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Chris Down <chris@chrisdown.name>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NXu Yu <xuyu@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>

commit 9852ae3fe5293264f01c49f2571ef7688f7823ce upstream.

memory.stat and other files already consider subtrees in their output, and
we should too in order to not present an inconsistent interface.

The current situation is fairly confusing, because people interacting with
cgroups expect hierarchical behaviour in the vein of memory.stat,
cgroup.events, and other files.  For example, this causes confusion when
debugging reclaim events under low, as currently these always read "0" at
non-leaf memcg nodes, which frequently causes people to misdiagnose breach
behaviour.  The same confusion applies to other counters in this file when
debugging issues.

Aggregation is done at write time instead of at read-time since these
counters aren't hot (unlike memory.stat which is per-page, so it does it
at read time), and it makes sense to bundle this with the file
notifications.

After this patch, events are propagated up the hierarchy:

    [root@ktst ~]# cat /sys/fs/cgroup/system.slice/memory.events
    low 0
    high 0
    max 0
    oom 0
    oom_kill 0
    [root@ktst ~]# systemd-run -p MemoryMax=1 true
    Running as unit: run-r251162a189fb4562b9dabfdc9b0422f5.service
    [root@ktst ~]# cat /sys/fs/cgroup/system.slice/memory.events
    low 0
    high 0
    max 7
    oom 1
    oom_kill 1

As this is a change in behaviour, this can be reverted to the old
behaviour by mounting with the `memory_localevents' flag set.  However, we
use the new behaviour by default as there's a lack of evidence that there
are any current users of memory.events that would find this change
undesirable.

akpm: this is a behaviour change, so Cc:stable.  THis is so that
forthcoming distros which use cgroup v2 are more likely to pick up the
revised behaviour.

[xuyu: remove the new memory_localevents mount option because it is
rarely used]

Link: http://lkml.kernel.org/r/20190208224419.GA24772@chrisdown.nameSigned-off-by: NChris Down <chris@chrisdown.name>
Acked-by: NJohannes Weiner <hannes@cmpxchg.org>
Reviewed-by: NShakeel Butt <shakeelb@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NXu Yu <xuyu@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>

Export "memory.high" from cgroup v2 to v1 which can be used to archive
some memory QoS.

This is also a way of migrating to v2 gradually.
Signed-off-by: NXu Yu <xuyu@linux.alibaba.com>
Reviewed-by: NXunlei Pang <xlpang@linux.alibaba.com>
Reviewed-by: NYang Shi <yang.shi@linux.alibaba.com>

commit 30e235389faadb9e3d918887b1f126155d7d761d upstream.

Without this patch, the MAP_SYNC test case will cause a print_bad_pte
warning on arm64 as follows:

[   25.542693] BUG: Bad page map in process mapdax333 pte:2e8000448800f53 pmd:41ff5f003
[   25.546360] page:ffff7e0010220000 refcount:1 mapcount:-1 mapping:ffff8003e29c7440 index:0x0
[   25.550281] ext4_dax_aops
[   25.550282] name:"__aaabbbcccddd__"
[   25.551553] flags: 0x3ffff0000001002(referenced|reserved)
[   25.555802] raw: 03ffff0000001002 ffff8003dfffa908 0000000000000000 ffff8003e29c7440
[   25.559446] raw: 0000000000000000 0000000000000000 00000001fffffffe 0000000000000000
[   25.563075] page dumped because: bad pte
[   25.564938] addr:0000ffffbe05b000 vm_flags:208000fb anon_vma:0000000000000000 mapping:ffff8003e29c7440 index:0
[   25.574272] file:__aaabbbcccddd__ fault:ext4_dax_fault mmmmap:ext4_file_mmap readpage:0x0
[   25.578799] CPU: 1 PID: 1180 Comm: mapdax333 Not tainted 5.2.0+ #21
[   25.581702] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
[   25.585624] Call trace:
[   25.587008]  dump_backtrace+0x0/0x178
[   25.588799]  show_stack+0x24/0x30
[   25.590328]  dump_stack+0xa8/0xcc
[   25.591901]  print_bad_pte+0x18c/0x218
[   25.593628]  unmap_page_range+0x778/0xc00
[   25.595506]  unmap_single_vma+0x94/0xe8
[   25.597304]  unmap_vmas+0x90/0x108
[   25.598901]  unmap_region+0xc0/0x128
[   25.600566]  __do_munmap+0x284/0x3f0
[   25.602245]  __vm_munmap+0x78/0xe0
[   25.603820]  __arm64_sys_munmap+0x34/0x48
[   25.605709]  el0_svc_common.constprop.0+0x78/0x168
[   25.607956]  el0_svc_handler+0x34/0x90
[   25.609698]  el0_svc+0x8/0xc
[...]

The root cause is in _vm_normal_page, without the PTE_SPECIAL bit,
the return value will be incorrectly set to pfn_to_page(pfn) instead
of NULL. Besides, this patch also rewrite the pmd_mkdevmap to avoid
setting PTE_SPECIAL for pmd

The MAP_SYNC test case is as follows(Provided by Yibo Cai)
$#include <stdio.h>
$#include <string.h>
$#include <unistd.h>
$#include <sys/file.h>
$#include <sys/mman.h>

$#ifndef MAP_SYNC
$#define MAP_SYNC 0x80000
$#endif

/* mount -o dax /dev/pmem0 /mnt */
$#define F "/mnt/__aaabbbcccddd__"

int main(void)
{
    int fd;
    char buf[4096];
    void *addr;

    if ((fd = open(F, O_CREAT|O_TRUNC|O_RDWR, 0644)) < 0) {
        perror("open1");
        return 1;
    }

    if (write(fd, buf, 4096) != 4096) {
        perror("lseek");
        return 1;
    }

    addr = mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_SHARED|MAP_SYNC, fd, 0);
    if (addr == MAP_FAILED) {
        perror("mmap");
        printf("did you mount with '-o dax'?\n");
        return 1;
    }

    memset(addr, 0x55, 4096);

    if (munmap(addr, 4096) == -1) {
        perror("munmap");
        return 1;
    }

    close(fd);

    return 0;
}

Fixes: 73b20c84d42d ("arm64: mm: implement pte_devmap support")
Reported-by: NYibo Cai <Yibo.Cai@arm.com>
Acked-by: NWill Deacon <will@kernel.org>
Acked-by: NRobin Murphy <Robin.Murphy@arm.com>
Signed-off-by: NJia He <justin.he@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NShannon Zhao <shannon.zhao@linux.alibaba.com>
Reviewed-by: NYang Shi <yang.shi@linux.alibaba.com>

commit 73b20c84d42de14673a987816dd4d132c7b1f801 upstream.

In order for things like get_user_pages() to work on ZONE_DEVICE memory,
we need a software PTE bit to identify device-backed PFNs.  Hook this up
along with the relevant helpers to join in with ARCH_HAS_PTE_DEVMAP.

[robin.murphy@arm.com: build fixes]
  Link: http://lkml.kernel.org/r/13026c4e64abc17133bbfa07d7731ec6691c0bcd.1559050949.git.robin.murphy@arm.com
Link: http://lkml.kernel.org/r/817d92886fc3b33bcbf6e105ee83a74babb3a5aa.1558547956.git.robin.murphy@arm.comSigned-off-by: NRobin Murphy <robin.murphy@arm.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NShannon Zhao <shannon.zhao@linux.alibaba.com>
Reviewed-by: NYang Shi <yang.shi@linux.alibaba.com>

commit 175967318c3018d01931ac950c82adab5deb47ca upstream.

ARCH_HAS_ZONE_DEVICE is somewhat meaningless in itself, and combined
with the long-out-of-date comment can lead to the impression than an
architecture may just enable it (since __add_pages() now "comprehends
device memory" for itself) and expect things to work.

In practice, however, ZONE_DEVICE users have little chance of
functioning correctly without __HAVE_ARCH_PTE_DEVMAP, so let's clean
that up the same way as ARCH_HAS_PTE_SPECIAL and make it the proper
dependency so the real situation is clearer.

Link: http://lkml.kernel.org/r/87554aa78478a02a63f2c4cf60a847279ae3eb3b.1558547956.git.robin.murphy@arm.comSigned-off-by: NRobin Murphy <robin.murphy@arm.com>
Acked-by: NDan Williams <dan.j.williams@intel.com>
Reviewed-by: NIra Weiny <ira.weiny@intel.com>
Acked-by: NOliver O'Halloran <oohall@gmail.com>
Reviewed-by: NAnshuman Khandual <anshuman.khandual@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NShannon Zhao <shannon.zhao@linux.alibaba.com>
Reviewed-by: NYang Shi <yang.shi@linux.alibaba.com>

commit 70927d02d409b5a79c3ed040ace5017da8284ede upstream.

When I tweaked the ftrace entry assembly in commit:

  3b23e4991fb66f6d ("arm64: implement ftrace with regs")

... my ifdeffery tweaks left ftrace_graph_caller undefined for
CONFIG_DYNAMIC_FTRACE && CONFIG_FUNCTION_GRAPH_TRACER when ftrace is
based on mcount.

The kbuild test robot reported that this issue is detected at link time:

| arch/arm64/kernel/entry-ftrace.o: In function `skip_ftrace_call':
| arch/arm64/kernel/entry-ftrace.S:238: undefined reference to `ftrace_graph_caller'
| arch/arm64/kernel/entry-ftrace.S:238:(.text+0x3c): relocation truncated to fit: R_AARCH64_CONDBR19 against undefined symbol
| `ftrace_graph_caller'
| arch/arm64/kernel/entry-ftrace.S:243: undefined reference to `ftrace_graph_caller'
| arch/arm64/kernel/entry-ftrace.S:243:(.text+0x54): relocation truncated to fit: R_AARCH64_CONDBR19 against undefined symbol
| `ftrace_graph_caller'

This patch fixes the ifdeffery so that the mcount version of
ftrace_graph_caller doesn't depend on CONFIG_DYNAMIC_FTRACE. At the same
time, a redundant #else is removed from the ifdeffery for the
patchable-function-entry version of ftrace_graph_caller.

Fixes: 3b23e4991fb66f6d ("arm64: implement ftrace with regs")
Reported-by: Nkbuild test robot <lkp@intel.com>
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Cc: Amit Daniel Kachhap <amit.kachhap@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Torsten Duwe <duwe@lst.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Zou Cao<zoucao@linux.alibaba.com>
Acked-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

fixed warnging as follow:
arm64ksyms.c:(___ksymtab+_mcount+0x0): undefined reference to `_mcount'
Signed-off-by: NZou Cao <zoucao@linux.alibaba.com>
Acked-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

commit 7dc48bf96aa0fc8aa5b38cc3e5c36ac03171e680 upstream.

The core ftrace hooks take the instrumented PC in x0, but for some
reason arm64's prepare_ftrace_return() takes this in x1.

For consistency, let's flip the argument order and always pass the
instrumented PC in x0.

There should be no functional change as a result of this patch.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Torsten Duwe <duwe@suse.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: Zou Cao<zoucao@linux.alibaba.com>
Acked-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

commit 49e258e05e8e56d53af20be481b311c43d7c286b upstream.

The save_return_regs and restore_return_regs macros are only used by
return_to_handler, and having them defined out-of-line only serves to
obscure the logic.

Before we complicate, let's clean this up and fold the logic directly
into return_to_handler, saving a few lines of macro boilerplate in the
process. At the same time, a missing trailing space is added to the
comments, fixing a code style violation.

There should be no functional change as a result of this patch.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Torsten Duwe <duwe@suse.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: Zou Cao<zoucao@linux.alibaba.com>
Acked-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

commit ad697a1aecac19ec351063b5d8e6fc9d4bca7ee5 upstream.

Declaring a global symbol in assembly is tedious, error-prone, and
painful to read. While ENTRY() exists, this is supposed to be used for
function entry points, and this affects alignment in a potentially
undesireable manner.

Instead, let's add a generic GLOBAL() macro for this, as x86 added
locally in commit:

  95695547 ("x86: asm linkage - introduce GLOBAL macro")

... thus allowing us to use this more freely in the kernel.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Torsten Duwe <duwe@suse.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: Zou Cao<zoucao@linux.alibaba.com>
Acked-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

commit 2809b392a62ae307da058a52d451b2fc3ce4de7e upstream.

This can be used for architectures implementing dynamic
ftrace via -fpatchable-function-entry.
Signed-off-by: NSven Schnelle <svens@stackframe.org>
Signed-off-by: NHelge Deller <deller@gmx.de>
Signed-off-by: Zou Cao<zoucao@linux.alibaba.com>
Acked-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

commit 3b23e4991fb66f6d152f9055ede271a726ef9f21 upstream

This patch implements FTRACE_WITH_REGS for arm64, which allows a traced
function's arguments (and some other registers) to be captured into a
struct pt_regs, allowing these to be inspected and/or modified. This is
a building block for live-patching, where a function's arguments may be
forwarded to another function. This is also necessary to enable ftrace
and in-kernel pointer authentication at the same time, as it allows the
LR value to be captured and adjusted prior to signing.

Using GCC's -fpatchable-function-entry=N option, we can have the
compiler insert a configurable number of NOPs between the function entry
point and the usual prologue. This also ensures functions are AAPCS
compliant (e.g. disabling inter-procedural register allocation).

For example, with -fpatchable-function-entry=2, GCC 8.1.0 compiles the
following:

| unsigned long bar(void);
|
| unsigned long foo(void)
| {
|         return bar() + 1;
| }

... to:

| <foo>:
|         nop
|         nop
|         stp     x29, x30, [sp, #-16]!
|         mov     x29, sp
|         bl      0 <bar>
|         add     x0, x0, #0x1
|         ldp     x29, x30, [sp], #16
|         ret

This patch builds the kernel with -fpatchable-function-entry=2,
prefixing each function with two NOPs. To trace a function, we replace
these NOPs with a sequence that saves the LR into a GPR, then calls an
ftrace entry assembly function which saves this and other relevant
registers:

| mov	x9, x30
| bl	<ftrace-entry>

Since patchable functions are AAPCS compliant (and the kernel does not
use x18 as a platform register), x9-x18 can be safely clobbered in the
patched sequence and the ftrace entry code.

There are now two ftrace entry functions, ftrace_regs_entry (which saves
all GPRs), and ftrace_entry (which saves the bare minimum). A PLT is
allocated for each within modules.
Signed-off-by: NTorsten Duwe <duwe@suse.de>
[Mark: rework asm, comments, PLTs, initialization, commit message]
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Reviewed-by: NAmit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: NTorsten Duwe <duwe@suse.de>
Tested-by: NAmit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: NTorsten Duwe <duwe@suse.de>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Julien Thierry <jthierry@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Zou Cao<zoucao@linux.alibaba.com>
Acked-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

commit 1f377e043b3b8ef68caffe47bdad794f4e2cb030 upstream

So that assembly code can more easily manipulate the FP (x29) within a
pt_regs, add an S_FP asm-offsets definition.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Reviewed-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: NTorsten Duwe <duwe@suse.de>
Tested-by: NAmit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: NTorsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Zou Cao<zoucao@linux.alibaba.com>
Acked-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

commit e3bf8a67f759b498e09999804c3837688e03b304 upstream

For FTRACE_WITH_REGS, we're going to want to generate a MOV (register)
instruction as part of the callsite intialization. As MOV (register) is
an alias for ORR (shifted register), we can generate this with
aarch64_insn_gen_logical_shifted_reg(), but it's somewhat verbose and
difficult to read in-context.

Add a aarch64_insn_gen_move_reg() wrapper for this case so that we can
write callers in a more straightforward way.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Reviewed-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: NTorsten Duwe <duwe@suse.de>
Tested-by: NAmit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: NTorsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Zou Cao<zoucao@linux.alibaba.com>
Acked-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

commit f1a54ae9af0da4d76239256ed640a93ab3aadac0 upstream

Currently we lazily-initialize a module's ftrace PLT at runtime when we
install the first ftrace call. To do so we have to apply a number of
sanity checks, transiently mark the module text as RW, and perform an
IPI as part of handling Neoverse-N1 erratum #1542419.

We only expect the ftrace trampoline to point at ftrace_caller() (AKA
FTRACE_ADDR), so let's simplify all of this by intializing the PLT at
module load time, before the module loader marks the module RO and
performs the intial I-cache maintenance for the module.

Thus we can rely on the module having been correctly intialized, and can
simplify the runtime work necessary to install an ftrace call in a
module. This will also allow for the removal of module_disable_ro().

Tested by forcing ftrace_make_call() to use the module PLT, and then
loading up a module after setting up ftrace with:

| echo ":mod:<module-name>" > set_ftrace_filter;
| echo function > current_tracer;
| modprobe <module-name>

Since FTRACE_ADDR is only defined when CONFIG_DYNAMIC_FTRACE is
selected, we wrap its use along with most of module_init_ftrace_plt()
with ifdeffery rather than using IS_ENABLED().
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Reviewed-by: NAmit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: NTorsten Duwe <duwe@suse.de>
Tested-by: NAmit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: NTorsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Zou Cao<zoucao@linux.alibaba.com>
Acked-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

commit bd8b21d3dd661658addc1cd4cc869bab11d28596 upstream

When we load a module, we have to perform some special work for a couple
of named sections. To do this, we iterate over all of the module's
sections, and perform work for each section we recognize.

To make it easier to handle the unexpected absence of a section, and to
make the section-specific logic easer to read, let's factor the section
search into a helper. Similar is already done in the core module loader,
and other architectures (and ideally we'd unify these in future).

If we expect a module to have an ftrace trampoline section, but it
doesn't have one, we'll now reject loading the module. When
ARM64_MODULE_PLTS is selected, any correctly built module should have
one (and this is assumed by arm64's ftrace PLT code) and the absence of
such a section implies something has gone wrong at build time.

Subsequent patches will make use of the new helper.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Reviewed-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: NTorsten Duwe <duwe@suse.de>
Tested-by: NAmit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: NTorsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Zou Cao<zoucao@linux.alibaba.com>
Acked-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

backport from a1326b17ac03a9012cb3d01e434aacb4d67a416c upstream

When using patchable-function-entry, the compiler will record the
callsites into a section named "__patchable_function_entries" rather
than "__mcount_loc". Let's abstract this difference behind a new
FTRACE_CALLSITE_SECTION, so that architectures don't have to handle this
explicitly (e.g. with custom module linker scripts).

As parisc currently handles this explicitly, it is fixed up accordingly,
with its custom linker script removed. Since FTRACE_CALLSITE_SECTION is
only defined when DYNAMIC_FTRACE is selected, the parisc module loading
code is updated to only use the definition in that case. When
DYNAMIC_FTRACE is not selected, modules shouldn't have this section, so
this removes some redundant work in that case.

To make sure that this is keep up-to-date for modules and the main
kernel, a comment is added to vmlinux.lds.h, with the existing ifdeffery
simplified for legibility.

I built parisc generic-{32,64}bit_defconfig with DYNAMIC_FTRACE enabled,
and verified that the section made it into the .ko files for modules.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NHelge Deller <deller@gmx.de>
Acked-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: NTorsten Duwe <duwe@suse.de>
Tested-by: NAmit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: NSven Schnelle <svens@stackframe.org>
Tested-by: NTorsten Duwe <duwe@suse.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Zou Cao<zoucao@linux.alibaba.com>
Acked-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

commit fbf6c73c5b264c25484fa9f449b5546569fe11f0 upstream

Architectures may need to perform special initialization of ftrace
callsites, and today they do so by special-casing ftrace_make_nop() when
the expected branch address is MCOUNT_ADDR. In some cases (e.g. for
patchable-function-entry), we don't have an mcount-like symbol and don't
want a synthetic MCOUNT_ADDR, but we may need to perform some
initialization of callsites.

To make it possible to separate initialization from runtime
modification, and to handle cases without an mcount-like symbol, this
patch adds an optional ftrace_init_nop() function that architectures can
implement, which does not pass a branch address.

Where an architecture does not provide ftrace_init_nop(), we will fall
back to the existing behaviour of calling ftrace_make_nop() with
MCOUNT_ADDR.

At the same time, ftrace_code_disable() is renamed to
ftrace_nop_initialize() to make it clearer that it is intended to
intialize a callsite into a disabled state, and is not for disabling a
callsite that has been runtime enabled. The kerneldoc description of rec
arguments is updated to cover non-mcount callsites.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Reviewed-by: NAmit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: NMiroslav Benes <mbenes@suse.cz>
Reviewed-by: NSteven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: NTorsten Duwe <duwe@suse.de>
Tested-by: NAmit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: NSven Schnelle <svens@stackframe.org>
Tested-by: NTorsten Duwe <duwe@suse.de>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Zou Cao<zoucao@linux.alibaba.com>
Acked-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

commit e2092740b72384e95b9c8a418536b35d628a1642 upstream.

In preparation for arm64 supporting ftrace built on other compiler
options, let's have Makefiles remove the $(CC_FLAGS_FTRACE) flags,
whatever these may be, rather than assuming '-pg'.

There should be no functional change as a result of this patch.
Reviewed-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NAndrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: NTorsten Duwe <duwe@suse.de>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: Zou Cao<zoucao@linux.alibaba.com>
Acked-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

commit e1a7eafb7350ff118e7538aca76b3f79e9280a8f upstream.

In preparation for arm64 supporting ftrace built on other compiler
options, let's have Makefiles remove the $(CC_FLAGS_FTRACE) flags,
whatever these maybe, rather than assuming '-pg'.

While at it, fix arm32 as well. There should be no functional change as
a result of this patch.
Reviewed-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NTorsten Duwe <duwe@suse.de>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: Zou Cao<zoucao@linux.alibaba.com>
Acked-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

commit edf072d36dbfdf74465b66988f30084b6c996fbf upstream.

In preparation for arm64 supporting ftrace built on other compiler
options, let's have the arm64 Makefiles remove the $(CC_FLAGS_FTRACE)
flags, whatever these may be, rather than assuming '-pg'.

There should be no functional change as a result of this patch.
Reviewed-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NTorsten Duwe <duwe@suse.de>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: Zou Cao<zoucao@linux.alibaba.com>
Acked-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

commit e4fe196642678565766815d99ab98a3a32d72dd4 upstream.

The global exports of ftrace_call and ftrace_graph_call are somewhat
painful to read. Let's use the generic GLOBAL() macro to ameliorate
matters.

There should be no functional change as a result of this patch.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Torsten Duwe <duwe@suse.de>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: Zou Cao<zoucao@linux.alibaba.com>
Acked-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

commit 41b57d1bb8a4084e651c1f9a754fca64952666a0 upstream.

Since architectures can implement ftrace using a variety of mechanisms,
generic code should always use CC_FLAGS_FTRACE rather than assuming that
ftrace is built using -pg.

Since commit:

  2464a609 ("ftrace: do not trace library functions")

... lib/Makefile has removed CC_FLAGS_FTRACE from KBUILD_CFLAGS, so ftrace is
disabled for all files under lib/.

Given that, we shouldn't explicitly remove -pg when building
lib/string.o, as this is redundant and bad form.

Clean things up accordingly.

There should be no functional change as a result of this patch.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Coly Li <colyli@suse.de>
Cc: Gary R Hook <gary.hook@amd.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Matthew Wilcox <willy@infradead.org>
Link: https://lkml.kernel.org/r/20190806162539.51918-1-mark.rutland@arm.com
Signed-off-by: Zou Cao<zoucao@linux.alibaba.com>
Acked-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>

commit b8e0ba7c8bea994011aff3b4c35256b180fab874 upstream.

KVM only supports PMD hugepages at stage 2. Now that the various page
handling routines are updated, extend the stage 2 fault handling to
map in PUD hugepages.

Addition of PUD hugepage support enables additional page sizes (e.g.,
1G with 4K granule) which can be useful on cores that support mapping
larger block sizes in the TLB entries.
Signed-off-by: NPunit Agrawal <punit.agrawal@arm.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
[ Replace BUG() => WARN_ON(1) for arm32 PUD helpers ]
Signed-off-by: NSuzuki Poulose <suzuki.poulose@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NShannon Zhao <shannon.zhao@linux.alibaba.com>
Acked-by: NZou Cao <zoucao@linux.alibaba.com>

commit 35a63966194dd994f44150f07398c62f8dca011e upstream.

In preparation for creating larger hugepages at Stage 2, add support
to the age handling notifiers for PUD hugepages when encountered.

Provide trivial helpers for arm32 to allow sharing code.
Signed-off-by: NPunit Agrawal <punit.agrawal@arm.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
[ Replaced BUG() => WARN_ON(1) for arm32 PUD helpers ]
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NShannon Zhao <shannon.zhao@linux.alibaba.com>
Acked-by: NZou Cao <zoucao@linux.alibaba.com>

commit eb3f0624ea082def887acc79e97934e27d0188b7 upstream.

In preparation for creating larger hugepages at Stage 2, extend the
access fault handling at Stage 2 to support PUD hugepages when
encountered.

Provide trivial helpers for arm32 to allow sharing of code.
Signed-off-by: NPunit Agrawal <punit.agrawal@arm.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
[ Replaced BUG() => WARN_ON(1) in PUD helpers ]
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NShannon Zhao <shannon.zhao@linux.alibaba.com>
Acked-by: NZou Cao <zoucao@linux.alibaba.com>

commit 86d1c55ea605025f78d026e7fc3a2bb4c3fc2d6a upstream.

In preparation for creating PUD hugepages at stage 2, add support for
detecting execute permissions on PUD page table entries. Faults due to
lack of execute permissions on page table entries is used to perform
i-cache invalidation on first execute.

Provide trivial implementations of arm32 helpers to allow sharing of
code.
Signed-off-by: NPunit Agrawal <punit.agrawal@arm.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
[ Replaced BUG() => WARN_ON(1) in arm32 PUD helpers ]
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NShannon Zhao <shannon.zhao@linux.alibaba.com>
Acked-by: NZou Cao <zoucao@linux.alibaba.com>

commit 4ea5af53114091e23a8fc279f25637e6c4e892c6 upstream.

In preparation for creating PUD hugepages at stage 2, add support for
write protecting PUD hugepages when they are encountered. Write
protecting guest tables is used to track dirty pages when migrating
VMs.

Also, provide trivial implementations of required kvm_s2pud_* helpers
to allow sharing of code with arm32.
Signed-off-by: NPunit Agrawal <punit.agrawal@arm.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
[ Replaced BUG() => WARN_ON() in arm32 pud helpers ]
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NShannon Zhao <shannon.zhao@linux.alibaba.com>
Acked-by: NZou Cao <zoucao@linux.alibaba.com>

commit f8df73388ee25b5e5f1d26249202e7126ca8139d upstream.

Introduce helpers to abstract architectural handling of the conversion
of pfn to page table entries and marking a PMD page table entry as a
block entry.

The helpers are introduced in preparation for supporting PUD hugepages
at stage 2 - which are supported on arm64 but do not exist on arm.
Signed-off-by: NPunit Agrawal <punit.agrawal@arm.com>
Reviewed-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: NChristoffer Dall <christoffer.dall@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NShannon Zhao <shannon.zhao@linux.alibaba.com>
Acked-by: NZou Cao <zoucao@linux.alibaba.com>

commit 6396b852e46e562f4742ed0a9042b537eb26b8aa upstream.

Stage 2 fault handler marks a page as executable if it is handling an
execution fault or if it was a permission fault in which case the
executable bit needs to be preserved.

The logic to decide if the page should be marked executable is
duplicated for PMD and PTE entries. To avoid creating another copy
when support for PUD hugepages is introduced refactor the code to
share the checks needed to mark a page table entry as executable.
Signed-off-by: NPunit Agrawal <punit.agrawal@arm.com>
Reviewed-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@arm.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NShannon Zhao <shannon.zhao@linux.alibaba.com>
Acked-by: NZou Cao <zoucao@linux.alibaba.com>

commit 3f58bf63455588a260b6abc8761c48bc8977b919 upstream.

The code for operations such as marking the pfn as dirty, and
dcache/icache maintenance during stage 2 fault handling is duplicated
between normal pages and PMD hugepages.

Instead of creating another copy of the operations when we introduce
PUD hugepages, let's share them across the different pagesizes.
Signed-off-by: NPunit Agrawal <punit.agrawal@arm.com>
Reviewed-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@arm.com>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NShannon Zhao <shannon.zhao@linux.alibaba.com>
Acked-by: NZou Cao <zoucao@linux.alibaba.com>

commit d1878af3a5a6ac00bc8a3edfecf80539ee9c546e upstream.

When KVM traps an unhandled sysreg/coproc access from a guest, it logs
the guest PC. To aid debugging, it would be helpful to know which
exception level the trap came from, along with other PSTATE/CPSR bits,
so let's log the PSTATE/CPSR too.
Acked-by: NChristoffer Dall <christoffer.dall@arm.com>
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NShannon Zhao <shannon.zhao@linux.alibaba.com>
Reviewed-by: NZou Cao <zoucao@linux.alibaba.com>

commit bd7d95cafb499e24903b7d21f9eeb2c5208160c2 upstream.

When we emulate a guest instruction, we don't advance the hardware
singlestep state machine, and thus the guest will receive a software
step exception after a next instruction which is not emulated by the
host.

We bodge around this in an ad-hoc fashion. Sometimes we explicitly check
whether userspace requested a single step, and fake a debug exception
from within the kernel. Other times, we advance the HW singlestep state
rely on the HW to generate the exception for us. Thus, the observed step
behaviour differs for host and guest.

Let's make this simpler and consistent by always advancing the HW
singlestep state machine when we skip an instruction. Thus we can rely
on the hardware to generate the singlestep exception for us, and never
need to explicitly check for an active-pending step, nor do we need to
fake a debug exception from the guest.

Cc: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: NChristoffer Dall <christoffer.dall@arm.com>
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NShannon Zhao <shannon.zhao@linux.alibaba.com>
Reviewed-by: NZou Cao <zoucao@linux.alibaba.com>

[ Upstream commit 1723fdec5fcbc4de3d26bbb23a9e1704ee258955 ]

While devm_gpiod_get_index_optional() returns NULL if the GPIO is not
present (i.e. -ENOENT), it may still return other error codes, like
-EPROBE_DEFER.  Currently these are not handled, leading to
unrecoverable failures later in case of probe deferral:

    gpiod_set_consumer_name: invalid GPIO (errorpointer)
    gpiod_direction_output: invalid GPIO (errorpointer)
    gpiod_set_value_cansleep: invalid GPIO (errorpointer)
    gpiod_set_value_cansleep: invalid GPIO (errorpointer)
    gpiod_set_value_cansleep: invalid GPIO (errorpointer)

Detect and propagate errors to fix this.

Fixes: f3186dd876697e69 ("spi: Optionally use GPIO descriptors for CS GPIOs")
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NMark Brown <broonie@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZou Cao <zoucao@linux.alibaba.com>
Reviewed-by: NBaoyou Xie <xie.baoyou@linux.alibaba.com>