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f7c83bcbfaf5 ("net: xfrm: use __this_cpu_read per-cpu helper") added a
__this_cpu_read() call inside ipcomp_alloc_tfms().
At the time, __this_cpu_read() required the caller to either not care
about races or to handle preemption/interrupt issues. 3.15 tightened
the rules around some per-cpu operations, and now __this_cpu_read()
should never be used in a preemptible context. On 3.15 and later, we
need to use this_cpu_read() instead.
syzkaller reported this leading to the following kernel BUG while
fuzzing sendmsg:
BUG: using __this_cpu_read() in preemptible [00000000] code: repro/3101
caller is ipcomp_init_state+0x185/0x990
CPU: 3 PID: 3101 Comm: repro Not tainted 4.16.0-rc4-00123-g86f84779d8e9 #154
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
Call Trace:
dump_stack+0xb9/0x115
check_preemption_disabled+0x1cb/0x1f0
ipcomp_init_state+0x185/0x990
? __xfrm_init_state+0x876/0xc20
? lock_downgrade+0x5e0/0x5e0
ipcomp4_init_state+0xaa/0x7c0
__xfrm_init_state+0x3eb/0xc20
xfrm_init_state+0x19/0x60
pfkey_add+0x20df/0x36f0
? pfkey_broadcast+0x3dd/0x600
? pfkey_sock_destruct+0x340/0x340
? pfkey_seq_stop+0x80/0x80
? __skb_clone+0x236/0x750
? kmem_cache_alloc+0x1f6/0x260
? pfkey_sock_destruct+0x340/0x340
? pfkey_process+0x62a/0x6f0
pfkey_process+0x62a/0x6f0
? pfkey_send_new_mapping+0x11c0/0x11c0
? mutex_lock_io_nested+0x1390/0x1390
pfkey_sendmsg+0x383/0x750
? dump_sp+0x430/0x430
sock_sendmsg+0xc0/0x100
___sys_sendmsg+0x6c8/0x8b0
? copy_msghdr_from_user+0x3b0/0x3b0
? pagevec_lru_move_fn+0x144/0x1f0
? find_held_lock+0x32/0x1c0
? do_huge_pmd_anonymous_page+0xc43/0x11e0
? lock_downgrade+0x5e0/0x5e0
? get_kernel_page+0xb0/0xb0
? _raw_spin_unlock+0x29/0x40
? do_huge_pmd_anonymous_page+0x400/0x11e0
? __handle_mm_fault+0x553/0x2460
? __fget_light+0x163/0x1f0
? __sys_sendmsg+0xc7/0x170
__sys_sendmsg+0xc7/0x170
? SyS_shutdown+0x1a0/0x1a0
? __do_page_fault+0x5a0/0xca0
? lock_downgrade+0x5e0/0x5e0
SyS_sendmsg+0x27/0x40
? __sys_sendmsg+0x170/0x170
do_syscall_64+0x19f/0x640
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x7f0ee73dfb79
RSP: 002b:00007ffe14fc15a8 EFLAGS: 00000207 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0ee73dfb79
RDX: 0000000000000000 RSI: 00000000208befc8 RDI: 0000000000000004
RBP: 00007ffe14fc15b0 R08: 00007ffe14fc15c0 R09: 00007ffe14fc15c0
R10: 0000000000000000 R11: 0000000000000207 R12: 0000000000400440
R13: 00007ffe14fc16b0 R14: 0000000000000000 R15: 0000000000000000
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
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Conflicts:
drivers/net/ethernet/emulex/benet/be.h
drivers/net/netconsole.c
net/bridge/br_private.h
Three mostly trivial conflicts.
The net/bridge/br_private.h conflict was a function signature (argument
addition) change overlapping with the extern removals from Joe Perches.
In drivers/net/netconsole.c we had one change adjusting a printk message
whilst another changed "printk(KERN_INFO" into "pr_info(".
Lastly, the emulex change was a new inline function addition overlapping
with Joe Perches's extern removals.
Signed-off-by: David S. Miller <davem@davemloft.net>
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scratches are per cpu, we can use vmalloc_node() for proper
NUMA affinity.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
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In ipcomp_compress(), sortirq is enabled too early, allowing the
per-cpu scratch buffer to be rewritten by ipcomp_decompress()
(called on the same CPU in softirq context) between populating
the buffer and copying the compressed data to the skb.
v2: as pointed out by Steffen Klassert, if we also move the
local_bh_disable() before reading the per-cpu pointers, we can
get rid of get_cpu()/put_cpu().
v3: removed ipcomp_decompress part (as explained by Herbert Xu,
it cannot be called from process context), get rid of cpu
variable (thanks to Eric Dumazet)
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
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this_cpu_ptr/this_cpu_read is faster than per_cpu_ptr(p, smp_processor_id())
and can reduce memory accesses.
The latter helper needs to find the offset for current cpu,
and needs more assembler instructions which objdump shows in following.
this_cpu_ptr relocates and address. this_cpu_read() relocates the address
and performs the fetch. this_cpu_read() saves you more instructions
since it can do the relocation and the fetch in one instruction.
per_cpu_ptr(p, smp_processor_id())：
1e: 65 8b 04 25 00 00 00 00 mov %gs:0x0,%eax
26: 48 98 cltq
28: 31 f6 xor %esi,%esi
2a: 48 c7 c7 00 00 00 00 mov $0x0,%rdi
31: 48 8b 04 c5 00 00 00 00 mov 0x0(,%rax,8),%rax
39: c7 44 10 04 14 00 00 00 movl $0x14,0x4(%rax,%rdx,1)
this_cpu_ptr(p)
1e: 65 48 03 14 25 00 00 00 00 add %gs:0x0,%rdx
27: 31 f6 xor %esi,%esi
29: c7 42 04 14 00 00 00 movl $0x14,0x4(%rdx)
30: 48 c7 c7 00 00 00 00 mov $0x0,%rdi
Signed-off-by: Shan Wei <davidshan@tencent.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
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To ease skb->truesize sanitization, its better to be able to localize
all references to skb frags size.
Define accessors : skb_frag_size() to fetch frag size, and
skb_frag_size_{set|add|sub}() to manipulate it.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
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percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
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Add __percpu sparse annotations to net.
These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors. This patch doesn't affect normal builds.
The macro and type tricks around snmp stats make things a bit
interesting. DEFINE/DECLARE_SNMP_STAT() macros mark the target field
as __percpu and SNMP_UPD_PO_STATS() macro is updated accordingly. All
snmp_mib_*() users which used to cast the argument to (void **) are
updated to cast it to (void __percpu **).
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Vlad Yasevich <vladislav.yasevich@hp.com>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
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When I made ipcomp use frags, I forgot to take out the original
truesize update that was added for pskb_expand_head. As we no
longer expand the head of skb, that update should have been removed.
This bug is not related to the truesize warnings since we only
made it bigger than what it should've been.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Removes legacy reinvent-the-wheel type thing. The generic
machinery integrates much better to automated debugging aids
such as kerneloops.org (and others), and is unambiguous due to
better naming. Non-intuively BUG_TRAP() is actually equal to
WARN_ON() rather than BUG_ON() though some might actually be
promoted to BUG_ON() but I left that to future.
I could make at least one BUILD_BUG_ON conversion.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
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When decompressing extremely large packets allocating them through
kmalloc is prone to failure. Therefore it's better to use page
frags instead.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This patch merges the IPv4/IPv6 IPComp implementations since most
of the code is identical. As a result future enhancements will no
longer need to be duplicated.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Greg Hackmann
David S. Miller
Eric Dumazet
Michal Kubecek
Shan Wei
Eric Dumazet
Ian Campbell
Tejun Heo
Herbert Xu
Ilpo Järvinen