When GCC realigns a function's stack, it sometimes uses %r13 as the DRAP
register, like:
push %r13
lea 0x10(%rsp), %r13
and $0xfffffffffffffff0, %rsp
pushq -0x8(%r13)
push %rbp
mov %rsp, %rbp
push %r13
...
mov -0x8(%rbp),%r13
leaveq
lea -0x10(%r13), %rsp
pop %r13
retq
Since %r13 was pushed onto the stack twice, its two stack locations need
to be stored separately. The first push of %r13 is its original value,
and the second push of %r13 is the caller's stack frame address.
Since %r13 is a callee-saved register, we need to track the stack
location of its original value separately from the DRAP register.
This fixes the following false positive warning:
lib/ubsan.o: warning: objtool: val_to_string.constprop.7()+0x97: leave instruction with modified stack frame
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: baa41469a7 ("objtool: Implement stack validation 2.0")
Link: http://lkml.kernel.org/r/3da23a6d4c5b3c1e21fc2ccc21a73941b97ff20a.1502401017.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Switching FS and GS is a mess, and the current code is still subtly
wrong: it assumes that "Loading a nonzero value into FS sets the
index and base", which is false on AMD CPUs if the value being
loaded is 1, 2, or 3.
(The current code came from commit 3e2b68d752 ("x86/asm,
sched/x86: Rewrite the FS and GS context switch code"), which made
it better but didn't fully fix it.)
Rewrite it to be much simpler and more obviously correct. This
should fix it fully on AMD CPUs and shouldn't adversely affect
performance.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chang Seok <chang.seok.bae@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Apparently the binutils 2.20 assembler can't handle the '&&' operator in
the UNWIND_HINT_REGS macro. Rearrange the macro to do without it.
This fixes the following error:
arch/x86/entry/entry_64.S: Assembler messages:
arch/x86/entry/entry_64.S:521: Error: non-constant expression in ".if" statement
arch/x86/entry/entry_64.S:521: Error: non-constant expression in ".if" statement
arch/x86/entry/entry_64.S:521: Error: non-constant expression in ".if" statement
arch/x86/entry/entry_64.S:521: Error: non-constant expression in ".if" statement
arch/x86/entry/entry_64.S:521: Error: non-constant expression in ".if" statement
arch/x86/entry/entry_64.S:521: Error: non-constant expression in ".if" statement
arch/x86/entry/entry_64.S:521: Error: non-constant expression in ".if" statement
arch/x86/entry/entry_64.S:521: Error: non-constant expression in ".if" statement
arch/x86/entry/entry_64.S:521: Error: non-constant expression in ".if" statement
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 39358a033b ("objtool, x86: Add facility for asm code to provide unwind hints")
Link: http://lkml.kernel.org/r/e2ad97c1ae49a484644b4aaa4dd3faa4d6d969b2.1502116651.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull pin control fixes from Linus Walleij:
"These are the pin control fixes I have gathered since the return from
my vacation. They boiled in -next a while so let's get them in.
Apart from the documentation build it is purely driver fixes. Which is
nice. The Intel fixes seem kind of important.
- Fix the documentation build as the docs were moved
- Correct the UART pin list on the Intel Merrifield
- Fix pin assignment and number of pins on the Marvell Armada 37xx
pin controller
- Cover the Setzer models in the Chromebook DMI quirk in the Intel
cheryview driver so they start working
- Add the missing "sim" function to the sunxi driver
- Fix USB pin definitions on Uniphier Pro4
- Smatch fix for invalid reference in the zx pin control driver"
* tag 'pinctrl-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
pinctrl: generic: update references to Documentation/pinctrl.txt
pinctrl: intel: merrifield: Correct UART pin lists
pinctrl: armada-37xx: Fix number of pin in south bridge
pinctrl: armada-37xx: Fix the pin 23 on south bridge
pinctrl: cherryview: Add Setzer models to the Chromebook DMI quirk
pinctrl: sunxi: add a missing function of A10/A20 pinctrl driver
pinctrl: uniphier: fix USB3 pin assignment for Pro4
pinctrl: zte: fix dereference of 'data' in zx_set_mux()
Commit 65d8fc777f ("futex: Remove requirement for lock_page() in
get_futex_key()") removed an unnecessary lock_page() with the
side-effect that page->mapping needed to be treated very carefully.
Two defensive warnings were added in case any assumption was missed and
the first warning assumed a correct application would not alter a
mapping backing a futex key. Since merging, it has not triggered for
any unexpected case but Mark Rutland reported the following bug
triggering due to the first warning.
kernel BUG at kernel/futex.c:679!
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 3695 Comm: syz-executor1 Not tainted 4.13.0-rc3-00020-g307fec773ba3 #3
Hardware name: linux,dummy-virt (DT)
task: ffff80001e271780 task.stack: ffff000010908000
PC is at get_futex_key+0x6a4/0xcf0 kernel/futex.c:679
LR is at get_futex_key+0x6a4/0xcf0 kernel/futex.c:679
pc : [<ffff00000821ac14>] lr : [<ffff00000821ac14>] pstate: 80000145
The fact that it's a bug instead of a warning was due to an unrelated
arm64 problem, but the warning itself triggered because the underlying
mapping changed.
This is an application issue but from a kernel perspective it's a
recoverable situation and the warning is unnecessary so this patch
removes the warning. The warning may potentially be triggered with the
following test program from Mark although it may be necessary to adjust
NR_FUTEX_THREADS to be a value smaller than the number of CPUs in the
system.
#include <linux/futex.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/syscall.h>
#include <sys/time.h>
#include <unistd.h>
#define NR_FUTEX_THREADS 16
pthread_t threads[NR_FUTEX_THREADS];
void *mem;
#define MEM_PROT (PROT_READ | PROT_WRITE)
#define MEM_SIZE 65536
static int futex_wrapper(int *uaddr, int op, int val,
const struct timespec *timeout,
int *uaddr2, int val3)
{
syscall(SYS_futex, uaddr, op, val, timeout, uaddr2, val3);
}
void *poll_futex(void *unused)
{
for (;;) {
futex_wrapper(mem, FUTEX_CMP_REQUEUE_PI, 1, NULL, mem + 4, 1);
}
}
int main(int argc, char *argv[])
{
int i;
mem = mmap(NULL, MEM_SIZE, MEM_PROT,
MAP_SHARED | MAP_ANONYMOUS, -1, 0);
printf("Mapping @ %p\n", mem);
printf("Creating futex threads...\n");
for (i = 0; i < NR_FUTEX_THREADS; i++)
pthread_create(&threads[i], NULL, poll_futex, NULL);
printf("Flipping mapping...\n");
for (;;) {
mmap(mem, MEM_SIZE, MEM_PROT,
MAP_FIXED | MAP_SHARED | MAP_ANONYMOUS, -1, 0);
}
return 0;
}
Reported-and-tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org # 4.7+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull i2c fixes from Wolfram Sang:
"The main thing is to allow empty id_tables for ACPI to make some
drivers get probed again. It looks a bit bigger than usual because it
needs some internal renaming, too.
Other than that, there is a fix for broken DSTDs, a super simple
enablement for ARM MPS, and two documentation fixes which I'd like to
see in v4.13 already"
* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: rephrase explanation of I2C_CLASS_DEPRECATED
i2c: allow i2c-versatile for ARM MPS platforms
i2c: designware: Some broken DSTDs use 1MiHz instead of 1MHz
i2c: designware: Print clock freq on invalid clock freq error
i2c: core: Allow empty id_table in ACPI case as well
i2c: mux: pinctrl: mention correct module name in Kconfig help text
Pull block fixes from Jens Axboe:
"Three patches that should go into this release.
Two of them are from Paolo and fix up some corner cases with BFQ, and
the last patch is from Ming and fixes up a potential usage count
imbalance regression due to the recent NOWAIT work"
* 'for-linus' of git://git.kernel.dk/linux-block:
blk-mq: don't leak preempt counter/q_usage_counter when allocating rq failed
block, bfq: consider also in_service_entity to state whether an entity is active
block, bfq: reset in_service_entity if it becomes idle
Pull crypto fixes from Herbert Xu:
"Fix two regressions in the inside-secure driver with respect to
hmac(sha1)"
* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: inside-secure - fix the sha state length in hmac_sha1_setkey
crypto: inside-secure - fix invalidation check in hmac_sha1_setkey
Pull networking fixes from David Miller:
"The pull requests are getting smaller, that's progress I suppose :-)
1) Fix infinite loop in CIPSO option parsing, from Yujuan Qi.
2) Fix remote checksum handling in VXLAN and GUE tunneling drivers,
from Koichiro Den.
3) Missing u64_stats_init() calls in several drivers, from Florian
Fainelli.
4) TCP can set the congestion window to an invalid ssthresh value
after congestion window reductions, from Yuchung Cheng.
5) Fix BPF jit branch generation on s390, from Daniel Borkmann.
6) Correct MIPS ebpf JIT merge, from David Daney.
7) Correct byte order test in BPF test_verifier.c, from Daniel
Borkmann.
8) Fix various crashes and leaks in ASIX driver, from Dean Jenkins.
9) Handle SCTP checksums properly in mlx4 driver, from Davide
Caratti.
10) We can potentially enter tcp_connect() with a cached route
already, due to fastopen, so we have to explicitly invalidate it.
11) skb_warn_bad_offload() can bark in legitimate situations, fix from
Willem de Bruijn"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (52 commits)
net: avoid skb_warn_bad_offload false positives on UFO
qmi_wwan: fix NULL deref on disconnect
ppp: fix xmit recursion detection on ppp channels
rds: Reintroduce statistics counting
tcp: fastopen: tcp_connect() must refresh the route
net: sched: set xt_tgchk_param par.net properly in ipt_init_target
net: dsa: mediatek: add adjust link support for user ports
net/mlx4_en: don't set CHECKSUM_COMPLETE on SCTP packets
qed: Fix a memory allocation failure test in 'qed_mcp_cmd_init()'
hysdn: fix to a race condition in put_log_buffer
s390/qeth: fix L3 next-hop in xmit qeth hdr
asix: Fix small memory leak in ax88772_unbind()
asix: Ensure asix_rx_fixup_info members are all reset
asix: Add rx->ax_skb = NULL after usbnet_skb_return()
bpf: fix selftest/bpf/test_pkt_md_access on s390x
netvsc: fix race on sub channel creation
bpf: fix byte order test in test_verifier
xgene: Always get clk source, but ignore if it's missing for SGMII ports
MIPS: Add missing file for eBPF JIT.
bpf, s390: fix build for libbpf and selftest suite
...
skb_warn_bad_offload triggers a warning when an skb enters the GSO
stack at __skb_gso_segment that does not have CHECKSUM_PARTIAL
checksum offload set.
Commit b2504a5dbe ("net: reduce skb_warn_bad_offload() noise")
observed that SKB_GSO_DODGY producers can trigger the check and
that passing those packets through the GSO handlers will fix it
up. But, the software UFO handler will set ip_summed to
CHECKSUM_NONE.
When __skb_gso_segment is called from the receive path, this
triggers the warning again.
Make UFO set CHECKSUM_UNNECESSARY instead of CHECKSUM_NONE. On
Tx these two are equivalent. On Rx, this better matches the
skb state (checksum computed), as CHECKSUM_NONE here means no
checksum computed.
See also this thread for context:
http://patchwork.ozlabs.org/patch/799015/
Fixes: b2504a5dbe ("net: reduce skb_warn_bad_offload() noise")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit e5dadc65f9 ("ppp: Fix false xmit recursion detect with two ppp
devices") dropped the xmit_recursion counter incrementation in
ppp_channel_push() and relied on ppp_xmit_process() for this task.
But __ppp_channel_push() can also send packets directly (using the
.start_xmit() channel callback), in which case the xmit_recursion
counter isn't incremented anymore. If such packets get routed back to
the parent ppp unit, ppp_xmit_process() won't notice the recursion and
will call ppp_channel_push() on the same channel, effectively creating
the deadlock situation that the xmit_recursion mechanism was supposed
to prevent.
This patch re-introduces the xmit_recursion counter incrementation in
ppp_channel_push(). Since the xmit_recursion variable is now part of
the parent ppp unit, incrementation is skipped if the channel doesn't
have any. This is fine because only packets routed through the parent
unit may enter the channel recursively.
Finally, we have to ensure that pch->ppp is not going to be modified
while executing ppp_channel_push(). Instead of taking this lock only
while calling ppp_xmit_process(), we now have to hold it for the full
ppp_channel_push() execution. This respects the ppp locks ordering
which requires locking ->upl before ->downl.
Fixes: e5dadc65f9 ("ppp: Fix false xmit recursion detect with two ppp devices")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Juergen Gross
Josh Poimboeuf
Andy Lutomirski
Peter Zijlstra
Ingo Molnar
Linus Torvalds
Mel Gorman
Willem de Bruijn
Bjørn Mork
Guillaume Nault