The macro 'A' used in internal BPF interpreter:
#define A regs[insn->a_reg]
was easily confused with the name of classic BPF register 'A', since
'A' would mean two different things depending on context.
This patch is trying to clean up the naming and clarify its usage in the
following way:
- A and X are names of two classic BPF registers
- BPF_REG_A denotes internal BPF register R0 used to map classic register A
in internal BPF programs generated from classic
- BPF_REG_X denotes internal BPF register R7 used to map classic register X
in internal BPF programs generated from classic
- internal BPF instruction format:
struct sock_filter_int {
__u8 code; /* opcode */
__u8 dst_reg:4; /* dest register */
__u8 src_reg:4; /* source register */
__s16 off; /* signed offset */
__s32 imm; /* signed immediate constant */
};
- BPF_X/BPF_K is 1 bit used to encode source operand of instruction
In classic:
BPF_X - means use register X as source operand
BPF_K - means use 32-bit immediate as source operand
In internal:
BPF_X - means use 'src_reg' register as source operand
BPF_K - means use 32-bit immediate as source operand
Suggested-by: Chema Gonzalez <chema@google.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Chema Gonzalez <chema@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
include/net/inetpeer.h
net/ipv6/output_core.c
Changes in net were fixing bugs in code removed in net-next.
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull x86 fix from Peter Anvin:
"A single quite small patch that managed to get overlooked earlier, to
prevent a user space triggerable oops on systems without HPET"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, vdso: Fix an OOPS accessing the HPET mapping w/o an HPET
While I play inhouse patches with much memory pressure on qemu-kvm,
3.14 kernel was randomly crashed. The reason was kernel stack overflow.
When I investigated the problem, the callstack was a little bit deeper
by involve with reclaim functions but not direct reclaim path.
I tried to diet stack size of some functions related with alloc/reclaim
so did a hundred of byte but overflow was't disappeard so that I encounter
overflow by another deeper callstack on reclaim/allocator path.
Of course, we might sweep every sites we have found for reducing
stack usage but I'm not sure how long it saves the world(surely,
lots of developer start to add nice features which will use stack
agains) and if we consider another more complex feature in I/O layer
and/or reclaim path, it might be better to increase stack size(
meanwhile, stack usage on 64bit machine was doubled compared to 32bit
while it have sticked to 8K. Hmm, it's not a fair to me and arm64
already expaned to 16K. )
So, my stupid idea is just let's expand stack size and keep an eye
toward stack consumption on each kernel functions via stacktrace of ftrace.
For example, we can have a bar like that each funcion shouldn't exceed 200K
and emit the warning when some function consumes more in runtime.
Of course, it could make false positive but at least, it could make a
chance to think over it.
I guess this topic was discussed several time so there might be
strong reason not to increase kernel stack size on x86_64, for me not
knowing so Ccing x86_64 maintainers, other MM guys and virtio
maintainers.
Here's an example call trace using up the kernel stack:
Depth Size Location (51 entries)
----- ---- --------
0) 7696 16 lookup_address
1) 7680 16 _lookup_address_cpa.isra.3
2) 7664 24 __change_page_attr_set_clr
3) 7640 392 kernel_map_pages
4) 7248 256 get_page_from_freelist
5) 6992 352 __alloc_pages_nodemask
6) 6640 8 alloc_pages_current
7) 6632 168 new_slab
8) 6464 8 __slab_alloc
9) 6456 80 __kmalloc
10) 6376 376 vring_add_indirect
11) 6000 144 virtqueue_add_sgs
12) 5856 288 __virtblk_add_req
13) 5568 96 virtio_queue_rq
14) 5472 128 __blk_mq_run_hw_queue
15) 5344 16 blk_mq_run_hw_queue
16) 5328 96 blk_mq_insert_requests
17) 5232 112 blk_mq_flush_plug_list
18) 5120 112 blk_flush_plug_list
19) 5008 64 io_schedule_timeout
20) 4944 128 mempool_alloc
21) 4816 96 bio_alloc_bioset
22) 4720 48 get_swap_bio
23) 4672 160 __swap_writepage
24) 4512 32 swap_writepage
25) 4480 320 shrink_page_list
26) 4160 208 shrink_inactive_list
27) 3952 304 shrink_lruvec
28) 3648 80 shrink_zone
29) 3568 128 do_try_to_free_pages
30) 3440 208 try_to_free_pages
31) 3232 352 __alloc_pages_nodemask
32) 2880 8 alloc_pages_current
33) 2872 200 __page_cache_alloc
34) 2672 80 find_or_create_page
35) 2592 80 ext4_mb_load_buddy
36) 2512 176 ext4_mb_regular_allocator
37) 2336 128 ext4_mb_new_blocks
38) 2208 256 ext4_ext_map_blocks
39) 1952 160 ext4_map_blocks
40) 1792 384 ext4_writepages
41) 1408 16 do_writepages
42) 1392 96 __writeback_single_inode
43) 1296 176 writeback_sb_inodes
44) 1120 80 __writeback_inodes_wb
45) 1040 160 wb_writeback
46) 880 208 bdi_writeback_workfn
47) 672 144 process_one_work
48) 528 112 worker_thread
49) 416 240 kthread
50) 176 176 ret_from_fork
[ Note: the problem is exacerbated by certain gcc versions that seem to
generate much bigger stack frames due to apparently bad coalescing of
temporaries and generating too many spills. Rusty saw gcc-4.6.4 using
35% more stack on the virtio path than 4.8.2 does, for example.
Minchan not only uses such a bad gcc version (4.6.3 in his case), but
some of the stack use is due to debugging (CONFIG_DEBUG_PAGEALLOC is
what causes that kernel_map_pages() frame, for example). But we're
clearly getting too close.
The VM code also seems to have excessive stack frames partly for the
same compiler reason, triggered by excessive inlining and lots of
function arguments.
We need to improve on our stack use, but in the meantime let's do this
simple stack increase too. Unlike most earlier reports, there is
nothing simple that stands out as being really horribly wrong here,
apart from the fact that the stack frames are just bigger than they
should need to be. - Linus ]
Signed-off-by: Minchan Kim <minchan@kernel.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michael S Tsirkin <mst@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: PJ Waskiewicz <pjwaskiewicz@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The PPC fixes are important because they fix breakage that is new in 3.15.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"Small fixes for x86, slightly larger fixes for PPC, and a forgotten
s390 patch. The PPC fixes are important because they fix breakage
that is new in 3.15"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: s390: announce irqfd capability
KVM: x86: disable master clock if TSC is reset during suspend
KVM: vmx: disable APIC virtualization in nested guests
KVM guest: Make pv trampoline code executable
KVM: PPC: Book3S: ifdef on CONFIG_KVM_BOOK3S_32_HANDLER for 32bit
KVM: PPC: Book3S HV: Add missing code for transaction reclaim on guest exit
KVM: PPC: Book3S: HV: make _PAGE_NUMA take effect
Conflicts:
drivers/net/bonding/bond_alb.c
drivers/net/ethernet/altera/altera_msgdma.c
drivers/net/ethernet/altera/altera_sgdma.c
net/ipv6/xfrm6_output.c
Several cases of overlapping changes.
The xfrm6_output.c has a bug fix which overlaps the renaming
of skb->local_df to skb->ignore_df.
In the Altera TSE driver cases, the register access cleanups
in net-next overlapped with bug fixes done in net.
Similarly a bug fix to send ALB packets in the bonding driver using
the right source address overlaps with cleanups in net-next.
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking fixes from David Miller:
"It looks like a sizeble collection but this is nearly 3 weeks of bug
fixing while you were away.
1) Fix crashes over IPSEC tunnels with NAT, the latter can reroute
the packet through a non-IPSEC protected path and the code has to
be able to handle SKBs attached to routes lacking an attached xfrm
state. From Steffen Klassert.
2) Fix OOPSs in ipv4 and ipv6 ipsec layers for unsupported
sub-protocols, also from Steffen Klassert.
3) Set local_df on fragmented netfilter skbs otherwise we won't be
able to forward successfully, from Florian Westphal.
4) cdc_mbim ipv6 neighbour code does __vlan_find_dev_deep without
holding RCU lock, from Bjorn Mork.
5) local_df test in ip_may_fragment is inverted, from Florian
Westphal.
6) jme driver doesn't check for DMA mapping failures, from Neil
Horman.
7) qlogic driver doesn't calculate number of TX queues properly, from
Shahed Shaikh.
8) fib_info_cnt can drift irreversibly positive if we fail to
allocate the fi->fib_metrics array, from Sergey Popovich.
9) Fix use after free in ip6_route_me_harder(), also from Sergey
Popovich.
10) When SYSCTL is disabled, we don't handle local_port_range and
ping_group_range defaults properly at all, from Cong Wang.
11) Unaccelerated VLAN tagged frames improperly handled by cdc_mbim
driver, fix from Bjorn Mork.
12) cassini driver needs nested lock annotations for TX locking, from
Emil Goode.
13) On init error ipv6 VTI driver can unregister pernet ops twice,
oops. Fix from Mahtias Krause.
14) If macvlan device is down, don't propagate IFF_ALLMULTI changes,
from Peter Christensen.
15) Missing NULL pointer check while parsing netlink config options in
ip6_tnl_validate(). From Susant Sahani.
16) Fix handling of neighbour entries during ipv6 router reachability
probing, from Duan Jiong.
17) x86 and s390 JIT address randomization has some address
calculation bugs leading to crashes, from Alexei Starovoitov and
Heiko Carstens.
18) Clear up those uglies with nop patching and net_get_random_once(),
from Hannes Frederic Sowa.
19) Option length miscalculated in ip6_append_data(), fix also from
Hannes Frederic Sowa.
20) A while ago we fixed a race during device unregistry when a
namespace went down, turns out there is a second place that needs
similar protection. From Cong Wang.
21) In the new Altera TSE driver multicast filtering isn't working,
disable it and just use promisc mode until the cause is found.
From Vince Bridgers.
22) When we disable router enabling in ipv6 we have to flush the
cached routes explicitly, from Duan Jiong.
23) NBMA tunnels should not cache routes on the tunnel object because
the key is variable, from Timo Teräs.
24) With stacked devices GRO information in skb->cb[] can be not setup
properly, make sure it is in all code paths. From Eric Dumazet.
25) Really fix stacked vlan locking, multiple levels of nesting with
intervening non-vlan devices are possible. From Vlad Yasevich.
26) Fallback ipip tunnel device's mtu is not setup properly, from
Steffen Klassert.
27) The packet scheduler's tcindex filter can crash because we
structure copy objects with list_head's inside, oops. From Cong
Wang.
28) Fix CHECKSUM_COMPLETE handling for ipv6 GRE tunnels, from Eric
Dumazet.
29) In some configurations 'itag' in __mkroute_input() can end up
being used uninitialized because of how fib_validate_source()
works. Fix it by explitly initializing itag to zero like all the
other fib_validate_source() callers do, from Li RongQing"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (116 commits)
batman: fix a bogus warning from batadv_is_on_batman_iface()
ipv4: initialise the itag variable in __mkroute_input
bonding: Send ALB learning packets using the right source
bonding: Don't assume 802.1Q when sending alb learning packets.
net: doc: Update references to skb->rxhash
stmmac: Remove unbalanced clk_disable call
ipv6: gro: fix CHECKSUM_COMPLETE support
net_sched: fix an oops in tcindex filter
can: peak_pci: prevent use after free at netdev removal
ip_tunnel: Initialize the fallback device properly
vlan: Fix build error wth vlan_get_encap_level()
can: c_can: remove obsolete STRICT_FRAME_ORDERING Kconfig option
MAINTAINERS: Pravin Shelar is Open vSwitch maintainer.
bnx2x: Convert return 0 to return rc
bonding: Fix alb mode to only use first level vlans.
bonding: Fix stacked device detection in arp monitoring
macvlan: Fix lockdep warnings with stacked macvlan devices
vlan: Fix lockdep warning with stacked vlan devices.
net: Allow for more then a single subclass for netif_addr_lock
net: Find the nesting level of a given device by type.
...
Pull perf fixes from Ingo Molnar:
"The biggest changes are fixes for races that kept triggering Trinity
crashes, plus liblockdep build fixes and smaller misc fixes.
The liblockdep bits in perf/urgent are a pull mistake - they should
have been in locking/urgent - but by the time I noticed other commits
were added and testing was done :-/ Sorry about that"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Fix a race between ring_buffer_detach() and ring_buffer_attach()
perf: Prevent false warning in perf_swevent_add
perf: Limit perf_event_attr::sample_period to 63 bits
tools/liblockdep: Remove all build files when doing make clean
tools/liblockdep: Build liblockdep from tools/Makefile
perf/x86/intel: Fix Silvermont's event constraints
perf: Fix perf_event_init_context()
perf: Fix race in removing an event
The oops can be triggered in qemu using -no-hpet (but not nohpet) by
running a 32-bit program and reading a couple of pages before the vdso.
This should send SIGBUS instead of OOPSing.
The bug was introduced by:
commit 7a59ed415f
Author: Stefani Seibold <stefani@seibold.net>
Date: Mon Mar 17 23:22:09 2014 +0100
x86, vdso: Add 32 bit VDSO time support for 32 bit kernel
which is new in 3.15.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Link: http://lkml.kernel.org/r/e99025d887d6670b6c4d81e6ccfeeb83770b21e9.1400109621.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Maps all internal BPF instructions into x86_64 instructions.
This patch replaces original BPF x64 JIT with internal BPF x64 JIT.
sysctl net.core.bpf_jit_enable is reused as on/off switch.
Performance:
1. old BPF JIT and internal BPF JIT generate equivalent x86_64 code.
No performance difference is observed for filters that were JIT-able before
Example assembler code for BPF filter "tcpdump port 22"
original BPF -> old JIT: original BPF -> internal BPF -> new JIT:
0: push %rbp 0: push %rbp
1: mov %rsp,%rbp 1: mov %rsp,%rbp
4: sub $0x60,%rsp 4: sub $0x228,%rsp
8: mov %rbx,-0x8(%rbp) b: mov %rbx,-0x228(%rbp) // prologue
12: mov %r13,-0x220(%rbp)
19: mov %r14,-0x218(%rbp)
20: mov %r15,-0x210(%rbp)
27: xor %eax,%eax // clear A
c: xor %ebx,%ebx 29: xor %r13,%r13 // clear X
e: mov 0x68(%rdi),%r9d 2c: mov 0x68(%rdi),%r9d
12: sub 0x6c(%rdi),%r9d 30: sub 0x6c(%rdi),%r9d
16: mov 0xd8(%rdi),%r8 34: mov 0xd8(%rdi),%r10
3b: mov %rdi,%rbx
1d: mov $0xc,%esi 3e: mov $0xc,%esi
22: callq 0xffffffffe1021e15 43: callq 0xffffffffe102bd75
27: cmp $0x86dd,%eax 48: cmp $0x86dd,%rax
2c: jne 0x0000000000000069 4f: jne 0x000000000000009a
2e: mov $0x14,%esi 51: mov $0x14,%esi
33: callq 0xffffffffe1021e31 56: callq 0xffffffffe102bd91
38: cmp $0x84,%eax 5b: cmp $0x84,%rax
3d: je 0x0000000000000049 62: je 0x0000000000000074
3f: cmp $0x6,%eax 64: cmp $0x6,%rax
42: je 0x0000000000000049 68: je 0x0000000000000074
44: cmp $0x11,%eax 6a: cmp $0x11,%rax
47: jne 0x00000000000000c6 6e: jne 0x0000000000000117
49: mov $0x36,%esi 74: mov $0x36,%esi
4e: callq 0xffffffffe1021e15 79: callq 0xffffffffe102bd75
53: cmp $0x16,%eax 7e: cmp $0x16,%rax
56: je 0x00000000000000bf 82: je 0x0000000000000110
58: mov $0x38,%esi 88: mov $0x38,%esi
5d: callq 0xffffffffe1021e15 8d: callq 0xffffffffe102bd75
62: cmp $0x16,%eax 92: cmp $0x16,%rax
65: je 0x00000000000000bf 96: je 0x0000000000000110
67: jmp 0x00000000000000c6 98: jmp 0x0000000000000117
69: cmp $0x800,%eax 9a: cmp $0x800,%rax
6e: jne 0x00000000000000c6 a1: jne 0x0000000000000117
70: mov $0x17,%esi a3: mov $0x17,%esi
75: callq 0xffffffffe1021e31 a8: callq 0xffffffffe102bd91
7a: cmp $0x84,%eax ad: cmp $0x84,%rax
7f: je 0x000000000000008b b4: je 0x00000000000000c2
81: cmp $0x6,%eax b6: cmp $0x6,%rax
84: je 0x000000000000008b ba: je 0x00000000000000c2
86: cmp $0x11,%eax bc: cmp $0x11,%rax
89: jne 0x00000000000000c6 c0: jne 0x0000000000000117
8b: mov $0x14,%esi c2: mov $0x14,%esi
90: callq 0xffffffffe1021e15 c7: callq 0xffffffffe102bd75
95: test $0x1fff,%ax cc: test $0x1fff,%rax
99: jne 0x00000000000000c6 d3: jne 0x0000000000000117
d5: mov %rax,%r14
9b: mov $0xe,%esi d8: mov $0xe,%esi
a0: callq 0xffffffffe1021e44 dd: callq 0xffffffffe102bd91 // MSH
e2: and $0xf,%eax
e5: shl $0x2,%eax
e8: mov %rax,%r13
eb: mov %r14,%rax
ee: mov %r13,%rsi
a5: lea 0xe(%rbx),%esi f1: add $0xe,%esi
a8: callq 0xffffffffe1021e0d f4: callq 0xffffffffe102bd6d
ad: cmp $0x16,%eax f9: cmp $0x16,%rax
b0: je 0x00000000000000bf fd: je 0x0000000000000110
ff: mov %r13,%rsi
b2: lea 0x10(%rbx),%esi 102: add $0x10,%esi
b5: callq 0xffffffffe1021e0d 105: callq 0xffffffffe102bd6d
ba: cmp $0x16,%eax 10a: cmp $0x16,%rax
bd: jne 0x00000000000000c6 10e: jne 0x0000000000000117
bf: mov $0xffff,%eax 110: mov $0xffff,%eax
c4: jmp 0x00000000000000c8 115: jmp 0x000000000000011c
c6: xor %eax,%eax 117: mov $0x0,%eax
c8: mov -0x8(%rbp),%rbx 11c: mov -0x228(%rbp),%rbx // epilogue
cc: leaveq 123: mov -0x220(%rbp),%r13
cd: retq 12a: mov -0x218(%rbp),%r14
131: mov -0x210(%rbp),%r15
138: leaveq
139: retq
On fully cached SKBs both JITed functions take 12 nsec to execute.
BPF interpreter executes the program in 30 nsec.
The difference in generated assembler is due to the following:
Old BPF imlements LDX_MSH instruction via sk_load_byte_msh() helper function
inside bpf_jit.S.
New JIT removes the helper and does it explicitly, so ldx_msh cost
is the same for both JITs, but generated code looks longer.
New JIT has 4 registers to save, so prologue/epilogue are larger,
but the cost is within noise on x64.
Old JIT checks whether first insn clears A and if not emits 'xor %eax,%eax'.
New JIT clears %rax unconditionally.
2. old BPF JIT doesn't support ANC_NLATTR, ANC_PAY_OFFSET, ANC_RANDOM
extensions. New JIT supports all BPF extensions.
Performance of such filters improves 2-4 times depending on a filter.
The longer the filter the higher performance gain.
Synthetic benchmarks with many ancillary loads see 20x speedup
which seems to be the maximum gain from JIT
Notes:
. net.core.bpf_jit_enable=2 + tools/net/bpf_jit_disasm is still functional
and can be used to see generated assembler
. there are two jit_compile() functions and code flow for classic filters is:
sk_attach_filter() - load classic BPF
bpf_jit_compile() - try to JIT from classic BPF
sk_convert_filter() - convert classic to internal
bpf_int_jit_compile() - JIT from internal BPF
seccomp and tracing filters will just call bpf_int_jit_compile()
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Split bpf_jit_compile() into two functions to improve readability
of for(pass++) loop. The change follows similar style of JIT compilers
for arm, powerpc, s390
The body of new do_jit() was not reformatted to reduce noise
in this patch, since the following patch replaces most of it.
Tested with BPF testsuite.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Checkin:
b3b42ac2cb x86-64, modify_ldt: Ban 16-bit segments on 64-bit kernels
disabled 16-bit segments on 64-bit kernels due to an information
leak. However, it does seem that people are genuinely using Wine to
run old 16-bit Windows programs on Linux.
A proper fix for this ("espfix64") is coming in the upcoming merge
window, but as a temporary fix, create a sysctl to allow the
administrator to re-enable support for 16-bit segments.
It adds a "/proc/sys/abi/ldt16" sysctl that defaults to zero (off). If
you hit this issue and care about your old Windows program more than
you care about a kernel stack address information leak, you can do
echo 1 > /proc/sys/abi/ldt16
as root (add it to your startup scripts), and you should be ok.
The sysctl table is only added if you have COMPAT support enabled on
x86-64, but I assume anybody who runs old windows binaries very much
does that ;)
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/CA%2B55aFw9BPoD10U1LfHbOMpHWZkvJTkMcfCs9s3urPr1YyWBxw@mail.gmail.com
Cc: <stable@vger.kernel.org>
Updating system_time from the kernel clock once master clock
has been enabled can result in time backwards event, in case
kernel clock frequency is lower than TSC frequency.
Disable master clock in case it is necessary to update it
from the resume path.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The invalidation is required in order to maintain proper semantics
under CoW conditions. In scenarios where a process clones several
threads, a thread operating on a core whose DTLB entry for a
particular hugepage has not been invalidated, will be reading from
the hugepage that belongs to the forked child process, even after
hugetlb_cow().
The thread will not see the updated page as long as the stale DTLB
entry remains cached, the thread attempts to write into the page,
the child process exits, or the thread gets migrated to a different
processor.
Signed-off-by: Anthony Iliopoulos <anthony.iliopoulos@huawei.com>
Link: http://lkml.kernel.org/r/20140514092948.GA17391@server-36.huawei.corp
Suggested-by: Shay Goikhman <shay.goikhman@huawei.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # v2.6.16+ (!)
bpf_alloc_binary() adds 128 bytes of room to JITed program image
and rounds it up to the nearest page size. If image size is close
to page size (like 4000), it is rounded to two pages:
round_up(4000 + 4 + 128) == 8192
then 'hole' is computed as 8192 - (4000 + 4) = 4188
If prandom_u32() % hole selects a number >= PAGE_SIZE - sizeof(*header)
then kernel will crash during bpf_jit_free():
kernel BUG at arch/x86/mm/pageattr.c:887!
Call Trace:
[<ffffffff81037285>] change_page_attr_set_clr+0x135/0x460
[<ffffffff81694cc0>] ? _raw_spin_unlock_irq+0x30/0x50
[<ffffffff810378ff>] set_memory_rw+0x2f/0x40
[<ffffffffa01a0d8d>] bpf_jit_free_deferred+0x2d/0x60
[<ffffffff8106bf98>] process_one_work+0x1d8/0x6a0
[<ffffffff8106bf38>] ? process_one_work+0x178/0x6a0
[<ffffffff8106c90c>] worker_thread+0x11c/0x370
since bpf_jit_free() does:
unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK;
struct bpf_binary_header *header = (void *)addr;
to compute start address of 'bpf_binary_header'
and header->pages will pass junk to:
set_memory_rw(addr, header->pages);
Fix it by making sure that &header->image[prandom_u32() % hole] and &header
are in the same page
Fixes: 314beb9bca ("x86: bpf_jit_comp: secure bpf jit against spraying attacks")
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ethernet/altera/altera_sgdma.c
net/netlink/af_netlink.c
net/sched/cls_api.c
net/sched/sch_api.c
The netlink conflict dealt with moving to netlink_capable() and
netlink_ns_capable() in the 'net' tree vs. supporting 'tc' operations
in non-init namespaces. These were simple transformations from
netlink_capable to netlink_ns_capable.
The Altera driver conflict was simply code removal overlapping some
void pointer cast cleanups in net-next.
Signed-off-by: David S. Miller <davem@davemloft.net>
One can logically expect that when the user has specified "nordrand",
the user doesn't want any use of the CPU random number generator,
neither RDRAND nor RDSEED, so disable both.
Reported-by: Stephan Mueller <smueller@chronox.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Link: http://lkml.kernel.org/r/21542339.0lFnPSyGRS@myon.chronox.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
With tk->wall_to_monotonic.tv_nsec being a 32-bit value on 32-bit
systems, (tk->wall_to_monotonic.tv_nsec << tk->shift) in update_vsyscall()
may lose upper bits or, worse, add them since compiler will do this:
(u64)(tk->wall_to_monotonic.tv_nsec << tk->shift)
instead of
((u64)tk->wall_to_monotonic.tv_nsec << tk->shift)
So if, for example, tv_nsec is 0x800000 and shift is 8 we will end up
with 0xffffffff80000000 instead of 0x80000000. And then we are stuck in
the subsequent 'while' loop.
We need an explicit cast.
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Link: http://lkml.kernel.org/r/1399648287-15178-1-git-send-email-boris.ostrovsky@oracle.com
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: <stable@vger.kernel.org> # v3.14
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Due to a typo the msr accessor function introduced in
22085a66c2 didn't have any lasting
effects because they accidentally wrote the old value back.
After c0a639ad0b this at the very least
this causes cpuid limits not to be lifted on some cpus leading to
missing capabilities for those.
Signed-off-by: Andres Freund <andres@anarazel.de>
Link: http://lkml.kernel.org/r/1399598957-7011-2-git-send-email-andres@anarazel.de
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
HPET on current Baytrail platform has accuracy problem to be
used as reliable clocksource/clockevent, so add a early quirk to
disable it.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1398327498-13163-2-git-send-email-feng.tang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
HPET on some platform has accuracy problem. Making
"boot_hpet_disable" extern so that we can runtime disable
the HPET timer by using quirk to check the platform.
Signed-off-by: Feng Tang <feng.tang@intel.com>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1398327498-13163-1-git-send-email-feng.tang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If you are using a 64-bit kernel with 32-bit userland, then
scripts/gcc-x86_64-has-stack-protector.sh invokes 32-bit gcc
with -mcmodel=kernel, which produces:
<stdin>:1:0: error: code model 'kernel' not supported in the 32 bit mode
and trips the "broken compiler" test at arch/x86/Makefile:120.
There are several places a fix is possible, but the following seems
cleanest. (But it's minimal; it would also be possible to factor
out a bunch of stuff from the two branches of the if.)
Signed-off-by: George Spelvin <linux@horizon.com>
Link: http://lkml.kernel.org/r/20140507210552.7581.qmail@ns.horizon.com
Cc: <stable@vger.kernel.org> # v3.14
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
While running a nested guest, we should disable APIC virtualization
controls (virtualized APIC register accesses, virtual interrupt
delivery and posted interrupts), because we do not expose them to
the nested guest.
Reported-by: Hu Yaohui <loki2441@gmail.com>
Suggested-by: Abel Gordon <abel@stratoscale.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Event 0x013c is not the same as fixed counter2, remove it from
Silvermont's event constraints.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1398755081-12471-1-git-send-email-zheng.z.yan@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As requested by Linus add explicit __visible to the asmlinkage users.
This marks all functions visible to assembler.
Tree sweep for arch/x86/*
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Link: http://lkml.kernel.org/r/1398984278-29319-3-git-send-email-andi@firstfloor.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
arch/x86/crypto/sha1_avx2_x86_64_asm.S introduced _end as a local
symbol, which broke the build under certain circumstances. Although
the wisdom of _end as a local symbol can definitely be questioned, the
build should not break for that reason.
Thus, filter the output of nm to only get global symbols of
appropriate type.
Reported-by: Andy Lutomirski <luto@amacapital.net>
Cc: Chandramouli Narayanan <mouli@linux.intel.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/n/tip-uxm3j3w3odglcwhafwq5tjqu@git.kernel.org
Note add32_with_carry(a, b) is suboptimal, as it forces
a and b in registers.
b could be a memory or a register operand.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
of the framebuffer when early_ioremap() is no longer available and
dropping __init from functions that may be invoked after
free_initmem() - Dave Young
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Merge tag 'efi-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/urgent
Pull EFI fix from Matt Fleming:
" * Fix earlyprintk=efi,keep support by switching to an ioremap() mapping
of the framebuffer when early_ioremap() is no longer available and
dropping __init from functions that may be invoked after
free_initmem() - Dave Young "
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull irq fixes from Thomas Gleixner:
"This udpate delivers:
- A fix for dynamic interrupt allocation on x86 which is required to
exclude the GSI interrupts from the dynamic allocatable range.
This was detected with the newfangled tablet SoCs which have GPIOs
and therefor allocate a range of interrupts. The MSI allocations
already excluded the GSI range, so we never noticed before.
- The last missing set_irq_affinity() repair, which was delayed due
to testing issues
- A few bug fixes for the armada SoC interrupt controller
- A memory allocation fix for the TI crossbar interrupt controller
- A trivial kernel-doc warning fix"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip: irq-crossbar: Not allocating enough memory
irqchip: armanda: Sanitize set_irq_affinity()
genirq: x86: Ensure that dynamic irq allocation does not conflict
linux/interrupt.h: fix new kernel-doc warnings
irqchip: armada-370-xp: Fix releasing of MSIs
irqchip: armada-370-xp: implement the ->check_device() msi_chip operation
irqchip: armada-370-xp: fix invalid cast of signed value into unsigned variable
earlyprintk=efi,keep will cause kernel hangs while freeing initmem like
below:
VFS: Mounted root (ext4 filesystem) readonly on device 254:2.
devtmpfs: mounted
Freeing unused kernel memory: 880K (ffffffff817d4000 - ffffffff818b0000)
It is caused by efi earlyprintk use __init function which will be freed
later. Such as early_efi_write is marked as __init, also it will use
early_ioremap which is init function as well.
To fix this issue, I added early initcall early_efi_map_fb which maps
the whole efi fb for later use. OTOH, adding a wrapper function
early_efi_map which calls early_ioremap before ioremap is available.
With this patch applied efi boot ok with earlyprintk=efi,keep console=efi
Signed-off-by: Dave Young <dyoung@redhat.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
Pull x86 fixes from Peter Anvin:
"Two very small changes: one fix for the vSMP Foundation platform, and
one to help LLVM not choke on options it doesn't understand (although
it probably should)"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/vsmp: Fix irq routing
x86: LLVMLinux: Wrap -mno-80387 with cc-option
the merge window.
- A fix from Oleg to async page faults.
- A bunch of small ARM changes.
- A trivial patch to use the new MSI-X API introduced during the merge
window.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
- Fix for a Haswell regression in nested virtualization, introduced
during the merge window.
- A fix from Oleg to async page faults.
- A bunch of small ARM changes.
- A trivial patch to use the new MSI-X API introduced during the merge
window.
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: ARM: vgic: Fix the overlap check action about setting the GICD & GICC base address.
KVM: arm/arm64: vgic: fix GICD_ICFGR register accesses
KVM: async_pf: mm->mm_users can not pin apf->mm
KVM: ARM: vgic: Fix sgi dispatch problem
MAINTAINERS: co-maintainance of KVM/{arm,arm64}
arm: KVM: fix possible misalignment of PGDs and bounce page
KVM: x86: Check for host supported fields in shadow vmcs
kvm: Use pci_enable_msix_exact() instead of pci_enable_msix()
ARM: KVM: disable KVM in Kconfig on big-endian systems
On x86 the allocation of irq descriptors may allocate interrupts which
are in the range of the GSI interrupts. That's wrong as those
interrupts are hardwired and we don't have the irq domain translation
like PPC. So one of these interrupts can be hooked up later to one of
the devices which are hard wired to it and the io_apic init code for
that particular interrupt line happily reuses that descriptor with a
completely different configuration so hell breaks lose.
Inside x86 we allocate dynamic interrupts from above nr_gsi_irqs,
except for a few usage sites which have not yet blown up in our face
for whatever reason. But for drivers which need an irq range, like the
GPIO drivers, we have no limit in place and we don't want to expose
such a detail to a driver.
To cure this introduce a function which an architecture can implement
to impose a lower bound on the dynamic interrupt allocations.
Implement it for x86 and set the lower bound to nr_gsi_irqs, which is
the end of the hardwired interrupt space, so all dynamic allocations
happen above.
That not only allows the GPIO driver to work sanely, it also protects
the bogus callsites of create_irq_nr() in hpet, uv, irq_remapping and
htirq code. They need to be cleaned up as well, but that's a separate
issue.
Reported-by: Jin Yao <yao.jin@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Mathias Nyman <mathias.nyman@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Krogerus Heikki <heikki.krogerus@intel.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1404241617360.28206@ionos.tec.linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
We track shadow vmcs fields through two static lists,
one for read only and another for r/w fields. However, with
addition of new vmcs fields, not all fields may be supported on
all hosts. If so, copy_vmcs12_to_shadow() trying to vmwrite on
unsupported hosts will result in a vmwrite error. For example, commit
36be0b9deb introduced GUEST_BNDCFGS, which is not supported
by all processors. Filter out host unsupported fields before
letting guests use shadow vmcs
Signed-off-by: Bandan Das <bsd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Correct IRQ routing in case a vSMP box is detected
but the Interrupt Routing Comply (IRC) value is set to
"comply", which leads to incorrect IRQ routing.
Before the patch:
When a vSMP box was detected and IRC was set to "comply",
users (and the kernel) couldn't effectively set the
destination of the IRQs. This is because the hook inside
vsmp_64.c always setup all CPUs as the IRQ destination using
cpumask_setall() as the return value for IRQ allocation mask.
Later, this "overrided" mask caused the kernel to set the IRQ
destination to the lowest online CPU in the mask (CPU0 usually).
After the patch:
When the IRC is set to "comply", users (and the kernel) can control
the destination of the IRQs as we will not be changing the
default "apic->vector_allocation_domain".
Signed-off-by: Oren Twaig <oren@scalemp.com>
Acked-by: Shai Fultheim <shai@scalemp.com>
Link: http://lkml.kernel.org/r/1398669697-2123-1-git-send-email-oren@scalemp.com
[ Minor readability edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch fixes a bug introduced by:
2422365780 ("perf/x86/intel: Use rdmsrl_safe() when initializing RAPL PMU")
The rdmsrl_safe() function returns 0 on success.
The current code was failing to detect the RAPL PMU
on real hardware (missing /sys/devices/power) because
the return value of rdmsrl_safe() was misinterpreted.
Signed-off-by: Stephane Eranian <eranian@google.com>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Venkatesh Srinivas <venkateshs@google.com>
Cc: peterz@infradead.org
Cc: zheng.z.yan@intel.com
Link: http://lkml.kernel.org/r/20140423170418.GA12767@quad
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 vdso fix from Peter Anvin:
"This is a single build fix for building with gold as opposed to GNU
ld. It got queued up separately and was expected to be pushed during
the merge window, but it got left behind"
* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, vdso: Make the vdso linker script compatible with Gold
Pull x86 fix from Ingo Molnar:
"This fixes the preemption-count imbalance crash reported by Owen
Kibel"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce: Fix CMCI preemption bugs
CPUs which should support the RAPL counters according to
Family/Model/Stepping may still issue #GP when attempting to access
the RAPL MSRs. This may happen when Linux is running under KVM and
we are passing-through host F/M/S data, for example. Use rdmsrl_safe
to first access the RAPL_POWER_UNIT MSR; if this fails, do not
attempt to use this PMU.
Signed-off-by: Venkatesh Srinivas <venkateshs@google.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1394739386-22260-1-git-send-email-venkateshs@google.com
Cc: zheng.z.yan@intel.com
Cc: eranian@google.com
Cc: ak@linux.intel.com
Cc: linux-kernel@vger.kernel.org
[ The patch also silently fixes another bug: rapl_pmu_init() didn't handle the memory alloc failure case previously. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
- Fix completely broken 32-bit PV guests caused by x86 refactoring
32-bit thread_info.
- Only enable ticketlock slow path on Xen (not bare metal).
- Fix two bugs with PV guests not shutting down when requested.
- Fix a minor memory leak in xen-pciback error path.
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Merge tag 'stable/for-linus-3.15-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull Xen fixes from David Vrabel:
"Xen regression and bug fixes for 3.15-rc1:
- fix completely broken 32-bit PV guests caused by x86 refactoring
32-bit thread_info.
- only enable ticketlock slow path on Xen (not bare metal)
- fix two bugs with PV guests not shutting down when requested
- fix a minor memory leak in xen-pciback error path"
* tag 'stable/for-linus-3.15-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/manage: Poweroff forcefully if user-space is not yet up.
xen/xenbus: Avoid synchronous wait on XenBus stalling shutdown/restart.
xen/spinlock: Don't enable them unconditionally.
xen-pciback: silence an unwanted debug printk
xen: fix memory leak in __xen_pcibk_add_pci_dev()
x86/xen: Fix 32-bit PV guests's usage of kernel_stack
Current kprobes in-kernel page fault handler doesn't
expect that its single-stepping can be interrupted by
an NMI handler which may cause a page fault(e.g. perf
with callback tracing).
In that case, the page-fault handled by kprobes and it
misunderstands the page-fault has been caused by the
single-stepping code and tries to recover IP address
to probed address.
But the truth is the page-fault has been caused by the
NMI handler, and do_page_fault failes to handle real
page fault because the IP address is modified and
causes Kernel BUGs like below.
----
[ 2264.726905] BUG: unable to handle kernel NULL pointer dereference at 0000000000000020
[ 2264.727190] IP: [<ffffffff813c46e0>] copy_user_generic_string+0x0/0x40
To handle this correctly, I fixed the kprobes fault
handler to ensure the faulted ip address is its own
single-step buffer instead of checking current kprobe
state.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Sandeepa Prabhu <sandeepa.prabhu@linaro.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: fche@redhat.com
Cc: systemtap@sourceware.org
Link: http://lkml.kernel.org/r/20140417081644.26341.52351.stgit@ltc230.yrl.intra.hitachi.co.jp
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The following commit:
27f6c573e0 ("x86, CMCI: Add proper detection of end of CMCI storms")
Added two preemption bugs:
- machine_check_poll() does a get_cpu_var() without a matching
put_cpu_var(), which causes preemption imbalance and crashes upon
bootup.
- it does percpu ops without disabling preemption. Preemption is not
disabled due to the mistaken use of a raw spinlock.
To fix these bugs fix the imbalance and change
cmci_discover_lock to a regular spinlock.
Reported-by: Owen Kibel <qmewlo@gmail.com>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Chen, Gong <gong.chen@linux.intel.com>
Cc: Josh Boyer <jwboyer@fedoraproject.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Alexander Todorov <atodorov@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/n/tip-jtjptvgigpfkpvtQxpEk1at2@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
--
arch/x86/kernel/cpu/mcheck/mce.c | 4 +---
arch/x86/kernel/cpu/mcheck/mce_intel.c | 18 +++++++++---------
2 files changed, 10 insertions(+), 12 deletions(-)
Pull x86 fixes from Ingo Molnar:
"Various fixes:
- reboot regression fix
- build message spam fix
- GPU quirk fix
- 'make kvmconfig' fix
plus the wire-up of the renameat2() system call on i386"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Remove the PCI reboot method from the default chain
x86/build: Supress "Nothing to be done for ..." messages
x86/gpu: Fix sign extension issue in Intel graphics stolen memory quirks
x86/platform: Fix "make O=dir kvmconfig"
i386: Wire up the renameat2() syscall
Pull perf fixes from Ingo Molnar:
"Tooling fixes, plus a simple hardware-enablement patch for the Intel
RAPL PMU (energy use measurement) on Haswell CPUs, which I hope is
still fine at this stage"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf tools: Instead of redirecting flex output, use -o
perf tools: Fix double free in perf test 21 (code-reading.c)
perf stat: Initialize statistics correctly
perf bench: Set more defaults in the 'numa' suite
perf bench: Fix segfault at the end of an 'all' execution
perf bench: Update manpage to mention numa and futex
perf probe: Use dwarf_getcfi_elf() instead of dwarf_getcfi()
perf probe: Fix to handle errors in line_range searching
perf probe: Fix --line option behavior
perf tools: Pick up libdw without explicit LIBDW_DIR
MAINTAINERS: Change e-mail to kernel.org one
perf callchains: Disable unwind libraries when libelf isn't found
tools lib traceevent: Do not call warning() directly
tools lib traceevent: Print event name when show warning if possible
perf top: Fix documentation of invalid -s option
perf/x86: Enable DRAM RAPL support on Intel Haswell
Steve reported a reboot hang and bisected it back to this commit:
a4f1987e4c x86, reboot: Add EFI and CF9 reboot methods into the default list
He heroically tested all reboot methods and found the following:
reboot=t # triple fault ok
reboot=k # keyboard ctrl FAIL
reboot=b # BIOS ok
reboot=a # ACPI FAIL
reboot=e # EFI FAIL [system has no EFI]
reboot=p # PCI 0xcf9 FAIL
And I think it's pretty obvious that we should only try PCI 0xcf9 as a
last resort - if at all.
The other observation is that (on this box) we should never try
the PCI reboot method, but close with either the 'triple fault'
or the 'BIOS' (terminal!) reboot methods.
Thirdly, CF9_COND is a total misnomer - it should be something like
CF9_SAFE or CF9_CAREFUL, and 'CF9' should be 'CF9_FORCE' ...
So this patch fixes the worst problems:
- it orders the actual reboot logic to follow the reboot ordering
pattern - it was in a pretty random order before for no good
reason.
- it fixes the CF9 misnomers and uses BOOT_CF9_FORCE and
BOOT_CF9_SAFE flags to make the code more obvious.
- it tries the BIOS reboot method before the PCI reboot method.
(Since 'BIOS' is a terminal reboot method resulting in a hang
if it does not work, this is essentially equivalent to removing
the PCI reboot method from the default reboot chain.)
- just for the miraculous possibility of terminal (resulting
in hang) reboot methods of triple fault or BIOS returning
without having done their job, there's an ordering between
them as well.
Reported-and-bisected-and-tested-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Aubrey <aubrey.li@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Link: http://lkml.kernel.org/r/20140404064120.GB11877@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
