[ Upstream commit c74fd80f2f ]
Revert the main part of commit:
af42b8d12f ("xen: fix MSI setup and teardown for PV on HVM guests")
That commit introduced reading the pci device's msi message data to see
if a pirq was previously configured for the device's msi/msix, and re-use
that pirq. At the time, that was the correct behavior. However, a
later change to Qemu caused it to call into the Xen hypervisor to unmap
all pirqs for a pci device, when the pci device disables its MSI/MSIX
vectors; specifically the Qemu commit:
c976437c7dba9c7444fb41df45468968aaa326ad
("qemu-xen: free all the pirqs for msi/msix when driver unload")
Once Qemu added this pirq unmapping, it was no longer correct for the
kernel to re-use the pirq number cached in the pci device msi message
data. All Qemu releases since 2.1.0 contain the patch that unmaps the
pirqs when the pci device disables its MSI/MSIX vectors.
This bug is causing failures to initialize multiple NVMe controllers
under Xen, because the NVMe driver sets up a single MSIX vector for
each controller (concurrently), and then after using that to talk to
the controller for some configuration data, it disables the single MSIX
vector and re-configures all the MSIX vectors it needs. So the MSIX
setup code tries to re-use the cached pirq from the first vector
for each controller, but the hypervisor has already given away that
pirq to another controller, and its initialization fails.
This is discussed in more detail at:
https://lists.xen.org/archives/html/xen-devel/2017-01/msg00447.html
Fixes: af42b8d12f ("xen: fix MSI setup and teardown for PV on HVM guests")
Signed-off-by: Dan Streetman <dan.streetman@canonical.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 21d25f6a42 upstream.
On a kernel with DEBUG_LOCKS, ioat_free_chan_resources triggers an
in_interrupt() warning. With PROVE_LOCKING, it reports detecting a
SOFTIRQ-safe to SOFTIRQ-unsafe lock ordering in the same code path.
This is because dma_generic_alloc_coherent() checks if the GFP flags
permit blocking. It allocates from different subsystems if blocking is
permitted. The free path knows how to return the memory to the correct
allocator. If GFP_KERNEL is specified then the alloc and free end up
going through cma_alloc(), which uses mutexes.
Given that ioat_free_chan_resources() can be called in interrupt
context, ioat_alloc_chan_resources() must specify GFP_NOWAIT so that the
allocations do not block and instead use an allocator that uses
spinlocks.
Signed-off-by: Krister Johansen <kjlx@templeofstupid.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 6760bf2ddd ]
Martin reported a verifier issue that hit the BUG_ON() for his
test case in the mark_reg_unknown_value() function:
[ 202.861380] kernel BUG at kernel/bpf/verifier.c:467!
[...]
[ 203.291109] Call Trace:
[ 203.296501] [<ffffffff811364d5>] mark_map_reg+0x45/0x50
[ 203.308225] [<ffffffff81136558>] mark_map_regs+0x78/0x90
[ 203.320140] [<ffffffff8113938d>] do_check+0x226d/0x2c90
[ 203.331865] [<ffffffff8113a6ab>] bpf_check+0x48b/0x780
[ 203.343403] [<ffffffff81134c8e>] bpf_prog_load+0x27e/0x440
[ 203.355705] [<ffffffff8118a38f>] ? handle_mm_fault+0x11af/0x1230
[ 203.369158] [<ffffffff812d8188>] ? security_capable+0x48/0x60
[ 203.382035] [<ffffffff811351a4>] SyS_bpf+0x124/0x960
[ 203.393185] [<ffffffff810515f6>] ? __do_page_fault+0x276/0x490
[ 203.406258] [<ffffffff816db320>] entry_SYSCALL_64_fastpath+0x13/0x94
This issue got uncovered after the fix in a08dd0da53 ("bpf: fix
regression on verifier pruning wrt map lookups"). The reason why it
wasn't noticed before was, because as mentioned in a08dd0da53,
mark_map_regs() was doing the id matching incorrectly based on the
uncached regs[regno].id. So, in the first loop, we walked all regs
and as soon as we found regno == i, then this reg's id was cleared
when calling mark_reg_unknown_value() thus that every subsequent
register was probed against id of 0 (which, in combination with the
PTR_TO_MAP_VALUE_OR_NULL type is an invalid condition that no other
register state can hold), and therefore wasn't type transitioned such
as in the spilled register case for the second loop.
Now since that got fixed, it turned out that 57a09bf0a4 ("bpf:
Detect identical PTR_TO_MAP_VALUE_OR_NULL registers") used
mark_reg_unknown_value() incorrectly for the spilled regs, and thus
hitting the BUG_ON() in some cases due to regno >= MAX_BPF_REG.
Although spilled regs have the same type as the non-spilled regs
for the verifier state, that is, struct bpf_reg_state, they are
semantically different from the non-spilled regs. In other words,
there can be up to 64 (MAX_BPF_STACK / BPF_REG_SIZE) spilled regs
in the stack, for example, register R<x> could have been spilled by
the program to stack location X, Y, Z, and in mark_map_regs() we
need to scan these stack slots of type STACK_SPILL for potential
registers that we have to transition from PTR_TO_MAP_VALUE_OR_NULL.
Therefore, depending on the location, the spilled_regs regno can
be a lot higher than just MAX_BPF_REG's value since we operate on
stack instead. The reset in mark_reg_unknown_value() itself is
just fine, only that the BUG_ON() was inappropriate for this. Fix
it by making a __mark_reg_unknown_value() version that can be
called from mark_map_reg() generically; we know for the non-spilled
case that the regno is always < MAX_BPF_REG anyway.
Fixes: 57a09bf0a4 ("bpf: Detect identical PTR_TO_MAP_VALUE_OR_NULL registers")
Reported-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a08dd0da53 ]
Commit 57a09bf0a4 ("bpf: Detect identical PTR_TO_MAP_VALUE_OR_NULL
registers") introduced a regression where existing programs stopped
loading due to reaching the verifier's maximum complexity limit,
whereas prior to this commit they were loading just fine; the affected
program has roughly 2k instructions.
What was found is that state pruning couldn't be performed effectively
anymore due to mismatches of the verifier's register state, in particular
in the id tracking. It doesn't mean that 57a09bf0a4 is incorrect per
se, but rather that verifier needs to perform a lot more work for the
same program with regards to involved map lookups.
Since commit 57a09bf0a4 is only about tracking registers with type
PTR_TO_MAP_VALUE_OR_NULL, the id is only needed to follow registers
until they are promoted through pattern matching with a NULL check to
either PTR_TO_MAP_VALUE or UNKNOWN_VALUE type. After that point, the
id becomes irrelevant for the transitioned types.
For UNKNOWN_VALUE, id is already reset to 0 via mark_reg_unknown_value(),
but not so for PTR_TO_MAP_VALUE where id is becoming stale. It's even
transferred further into other types that don't make use of it. Among
others, one example is where UNKNOWN_VALUE is set on function call
return with RET_INTEGER return type.
states_equal() will then fall through the memcmp() on register state;
note that the second memcmp() uses offsetofend(), so the id is part of
that since d2a4dd37f6 ("bpf: fix state equivalence"). But the bisect
pointed already to 57a09bf0a4, where we really reach beyond complexity
limit. What I found was that states_equal() often failed in this
case due to id mismatches in spilled regs with registers in type
PTR_TO_MAP_VALUE. Unlike non-spilled regs, spilled regs just perform
a memcmp() on their reg state and don't have any other optimizations
in place, therefore also id was relevant in this case for making a
pruning decision.
We can safely reset id to 0 as well when converting to PTR_TO_MAP_VALUE.
For the affected program, it resulted in a ~17 fold reduction of
complexity and let the program load fine again. Selftest suite also
runs fine. The only other place where env->id_gen is used currently is
through direct packet access, but for these cases id is long living, thus
a different scenario.
Also, the current logic in mark_map_regs() is not fully correct when
marking NULL branch with UNKNOWN_VALUE. We need to cache the destination
reg's id in any case. Otherwise, once we marked that reg as UNKNOWN_VALUE,
it's id is reset and any subsequent registers that hold the original id
and are of type PTR_TO_MAP_VALUE_OR_NULL won't be marked UNKNOWN_VALUE
anymore, since mark_map_reg() reuses the uncached regs[regno].id that
was just overridden. Note, we don't need to cache it outside of
mark_map_regs(), since it's called once on this_branch and the other
time on other_branch, which are both two independent verifier states.
A test case for this is added here, too.
Fixes: 57a09bf0a4 ("bpf: Detect identical PTR_TO_MAP_VALUE_OR_NULL registers")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit d2a4dd37f6 ]
Commmits 57a09bf0a4 ("bpf: Detect identical PTR_TO_MAP_VALUE_OR_NULL registers")
and 484611357c ("bpf: allow access into map value arrays") by themselves
are correct, but in combination they make state equivalence ignore 'id' field
of the register state which can lead to accepting invalid program.
Fixes: 57a09bf0a4 ("bpf: Detect identical PTR_TO_MAP_VALUE_OR_NULL registers")
Fixes: 484611357c ("bpf: allow access into map value arrays")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 57a09bf0a4 ]
A BPF program is required to check the return register of a
map_elem_lookup() call before accessing memory. The verifier keeps
track of this by converting the type of the result register from
PTR_TO_MAP_VALUE_OR_NULL to PTR_TO_MAP_VALUE after a conditional
jump ensures safety. This check is currently exclusively performed
for the result register 0.
In the event the compiler reorders instructions, BPF_MOV64_REG
instructions may be moved before the conditional jump which causes
them to keep their type PTR_TO_MAP_VALUE_OR_NULL to which the
verifier objects when the register is accessed:
0: (b7) r1 = 10
1: (7b) *(u64 *)(r10 -8) = r1
2: (bf) r2 = r10
3: (07) r2 += -8
4: (18) r1 = 0x59c00000
6: (85) call 1
7: (bf) r4 = r0
8: (15) if r0 == 0x0 goto pc+1
R0=map_value(ks=8,vs=8) R4=map_value_or_null(ks=8,vs=8) R10=fp
9: (7a) *(u64 *)(r4 +0) = 0
R4 invalid mem access 'map_value_or_null'
This commit extends the verifier to keep track of all identical
PTR_TO_MAP_VALUE_OR_NULL registers after a map_elem_lookup() by
assigning them an ID and then marking them all when the conditional
jump is observed.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 72ef9c4125 ]
This patch fixes a memory leak, which happens if the connection request
is not fulfilled between parsing the DCCP options and handling the SYN
(because e.g. the backlog is full), because we forgot to free the
list of ack vectors.
Reported-by: Jianwen Ji <jiji@redhat.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
