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Merge 4.9.195 into android-4.9-q
Changes in 4.9.195
Revert "Bluetooth: validate BLE connection interval updates"
IB/core: Add an unbound WQ type to the new CQ API
HID: prodikeys: Fix general protection fault during probe
HID: logitech: Fix general protection fault caused by Logitech driver
HID: hidraw: Fix invalid read in hidraw_ioctl
mtd: cfi_cmdset_0002: Use chip_good() to retry in do_write_oneword()
crypto: talitos - fix missing break in switch statement
media: tvp5150: fix switch exit in set control handler
ASoC: fsl: Fix of-node refcount unbalance in fsl_ssi_probe_from_dt()
ALSA: hda - Add laptop imic fixup for ASUS M9V laptop
objtool: Clobber user CFLAGS variable
mac80211: Print text for disassociation reason
mac80211: handle deauthentication/disassociation from TDLS peer
power: supply: sysfs: ratelimit property read error message
locking/lockdep: Add debug_locks check in __lock_downgrade()
irqchip/gic-v3-its: Fix LPI release for Multi-MSI devices
f2fs: check all the data segments against all node ones
Revert "f2fs: avoid out-of-range memory access"
f2fs: fix to do sanity check on segment bitmap of LFS curseg
drm: Flush output polling on shutdown
xfs: don't crash on null attr fork xfs_bmapi_read
Bluetooth: btrtl: Additional Realtek 8822CE Bluetooth devices
arcnet: provide a buffer big enough to actually receive packets
cdc_ncm: fix divide-by-zero caused by invalid wMaxPacketSize
macsec: drop skb sk before calling gro_cells_receive
net/phy: fix DP83865 10 Mbps HDX loopback disable function
net: qrtr: Stop rx_worker before freeing node
openvswitch: change type of UPCALL_PID attribute to NLA_UNSPEC
ppp: Fix memory leak in ppp_write
sch_netem: fix a divide by zero in tabledist()
skge: fix checksum byte order
usbnet: ignore endpoints with invalid wMaxPacketSize
usbnet: sanity checking of packet sizes and device mtu
mISDN: enforce CAP_NET_RAW for raw sockets
appletalk: enforce CAP_NET_RAW for raw sockets
ax25: enforce CAP_NET_RAW for raw sockets
ieee802154: enforce CAP_NET_RAW for raw sockets
nfc: enforce CAP_NET_RAW for raw sockets
ALSA: hda: Flush interrupts on disabling
regulator: lm363x: Fix off-by-one n_voltages for lm3632 ldo_vpos/ldo_vneg
ASoC: sgtl5000: Fix charge pump source assignment
dmaengine: bcm2835: Print error in case setting DMA mask fails
leds: leds-lp5562 allow firmware files up to the maximum length
media: dib0700: fix link error for dibx000_i2c_set_speed
media: exynos4-is: fix leaked of_node references
media: hdpvr: Add device num check and handling
sched/fair: Fix imbalance due to CPU affinity
sched/core: Fix CPU controller for !RT_GROUP_SCHED
x86/reboot: Always use NMI fallback when shutdown via reboot vector IPI fails
x86/apic: Soft disable APIC before initializing it
ALSA: hda - Show the fatal CORB/RIRB error more clearly
ALSA: i2c: ak4xxx-adda: Fix a possible null pointer dereference in build_adc_controls()
media: iguanair: add sanity checks
base: soc: Export soc_device_register/unregister APIs
ALSA: usb-audio: Skip bSynchAddress endpoint check if it is invalid
ia64:unwind: fix double free for mod->arch.init_unw_table
EDAC/altera: Use the proper type for the IRQ status bits
md: don't call spare_active in md_reap_sync_thread if all member devices can't work
md: don't set In_sync if array is frozen
efi: cper: print AER info of PCIe fatal error
media: gspca: zero usb_buf on error
dmaengine: iop-adma: use correct printk format strings
media: omap3isp: Don't set streaming state on random subdevs
net: lpc-enet: fix printk format strings
ARM: dts: imx7d: cl-som-imx7: make ethernet work again
media: radio/si470x: kill urb on error
media: hdpvr: add terminating 0 at end of string
media: dvb-core: fix a memory leak bug
PM / devfreq: passive: Use non-devm notifiers
PM / devfreq: exynos-bus: Correct clock enable sequence
media: saa7146: add cleanup in hexium_attach()
media: cpia2_usb: fix memory leaks
media: saa7134: fix terminology around saa7134_i2c_eeprom_md7134_gate()
media: ov9650: add a sanity check
ACPI / CPPC: do not require the _PSD method
arm64: kpti: ensure patched kernel text is fetched from PoU
nvmet: fix data units read and written counters in SMART log
iommu/amd: Silence warnings under memory pressure
libtraceevent: Change users plugin directory
ARM: dts: exynos: Mark LDO10 as always-on on Peach Pit/Pi Chromebooks
ACPI: custom_method: fix memory leaks
ACPI / PCI: fix acpi_pci_irq_enable() memory leak
hwmon: (acpi_power_meter) Change log level for 'unsafe software power cap'
md/raid1: fail run raid1 array when active disk less than one
dmaengine: ti: edma: Do not reset reserved paRAM slots
kprobes: Prohibit probing on BUG() and WARN() address
s390/crypto: xts-aes-s390 fix extra run-time crypto self tests finding
ASoC: dmaengine: Make the pcm->name equal to pcm->id if the name is not set
mmc: sdhci: Fix incorrect switch to HS mode
libertas: Add missing sentinel at end of if_usb.c fw_table
e1000e: add workaround for possible stalled packet
drm/amd/powerplay/smu7: enforce minimal VBITimeout (v2)
media: ttusb-dec: Fix info-leak in ttusb_dec_send_command()
ALSA: hda/realtek - Blacklist PC beep for Lenovo ThinkCentre M73/93
btrfs: extent-tree: Make sure we only allocate extents from block groups with the same type
media: omap3isp: Set device on omap3isp subdevs
PM / devfreq: passive: fix compiler warning
ALSA: firewire-tascam: handle error code when getting current source of clock
ALSA: firewire-tascam: check intermediate state of clock status and retry
IB/hfi1: Define variables as unsigned long to fix KASAN warning
printk: remove games with previous record flags
printk: Do not lose last line in kmsg buffer dump
fuse: fix missing unlock_page in fuse_writepage()
parisc: Disable HP HSC-PCI Cards to prevent kernel crash
KVM: x86: always stop emulation on page fault
KVM: x86: set ctxt->have_exception in x86_decode_insn()
KVM: x86: Manually calculate reserved bits when loading PDPTRS
media: sn9c20x: Add MSI MS-1039 laptop to flip_dmi_table
ASoC: Intel: NHLT: Fix debug print format
ASoC: Intel: Fix use of potentially uninitialized variable
ARM: zynq: Use memcpy_toio instead of memcpy on smp bring-up
alarmtimer: Use EOPNOTSUPP instead of ENOTSUPP
regulator: Defer init completion for a while after late_initcall
memcg, kmem: do not fail __GFP_NOFAIL charges
ovl: filter of trusted xattr results in audit
Btrfs: fix use-after-free when using the tree modification log
btrfs: Relinquish CPUs in btrfs_compare_trees
md/raid6: Set R5_ReadError when there is read failure on parity disk
cfg80211: Purge frame registrations on iftype change
/dev/mem: Bail out upon SIGKILL.
ext4: fix warning inside ext4_convert_unwritten_extents_endio
ext4: fix punch hole for inline_data file systems
quota: fix wrong condition in is_quota_modification()
hwrng: core - don't wait on add_early_randomness()
i2c: riic: Clear NACK in tend isr
CIFS: fix max ea value size
CIFS: Fix oplock handling for SMB 2.1+ protocols
btrfs: qgroup: Drop quota_root and fs_info parameters from update_qgroup_status_item
Btrfs: fix race setting up and completing qgroup rescan workers
Linux 4.9.195
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
[ Upstream commit e336b4027775cb458dc713745e526fa1a1996b2a ]
Since BUG() and WARN() may use a trap (e.g. UD2 on x86) to
get the address where the BUG() has occurred, kprobes can not
do single-step out-of-line that instruction. So prohibit
probing on such address.
Without this fix, if someone put a kprobe on WARN(), the
kernel will crash with invalid opcode error instead of
outputing warning message, because kernel can not find
correct bug address.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S . Miller <davem@davemloft.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Naveen N . Rao <naveen.n.rao@linux.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/156750890133.19112.3393666300746167111.stgit@devnote2
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry-picked from 85caa95b9f19bb3a26d7e025d1134760b69e0c40)
The CHECK_DATA_CORRUPTION() macro was designed to have callers do
something meaningful/protective on failure. However, using "return
false" in the macro too strictly limits the design patterns of callers.
Instead, let callers handle the logic test directly, but make sure that
the result IS checked by forcing __must_check (which appears to not be
able to be used directly on macro expressions).
Change-Id: I23a87276163e3760c6eba44d6072e495fd8ec65d
Link: http://lkml.kernel.org/r/20170206204547.GA125312@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Satya Tangirala <satyat@google.com>
(cherry-picked from de54ebbe26bb371a6f1fbc0593372232f04e3107)
The kernel checks for cases of data structure corruption under some
CONFIGs (e.g. CONFIG_DEBUG_LIST). When corruption is detected, some
systems may want to BUG() immediately instead of letting the system run
with known corruption. Usually these kinds of manipulation primitives can
be used by security flaws to gain arbitrary memory write control. This
provides a new config CONFIG_BUG_ON_DATA_CORRUPTION and a corresponding
macro CHECK_DATA_CORRUPTION for handling these situations. Notably, even
if not BUGing, the kernel should not continue processing the corrupted
structure.
This is inspired by similar hardening by Syed Rameez Mustafa in MSM
kernels, and in PaX and Grsecurity, which is likely in response to earlier
removal of the BUG calls in commit 924d9addb9 ("list debugging: use
WARN() instead of BUG()").
Change-Id: I81927d2aa3684d676934ac109833fe71f0bc0156
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Satya Tangirala <satyat@google.com>
Common approach to accessing register fields is to define
structures or sets of macros containing mask and shift pair.
Operations on the register are then performed as follows:
field = (reg >> shift) & mask;
reg &= ~(mask << shift);
reg |= (field & mask) << shift;
Defining shift and mask separately is tedious. Ivo van Doorn
came up with an idea of computing them at compilation time
based on a single shifted mask (later refined by Felix) which
can be used like this:
#define REG_FIELD 0x000ff000
field = FIELD_GET(REG_FIELD, reg);
reg &= ~REG_FIELD;
reg |= FIELD_PREP(REG_FIELD, field);
FIELD_{GET,PREP} macros take care of finding out what the
appropriate shift is based on compilation time ffs operation.
GENMASK can be used to define registers (which is usually
less error-prone and easier to match with datasheets).
This approach is the most convenient I've seen so to limit code
multiplication let's move the macros to a global header file.
Attempts to use static inlines instead of macros failed due
to false positive triggering of BUILD_BUG_ON()s, especially with
GCC < 6.0.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dinan Gunawardena <dinan.gunawardena@netronome.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
With next generation power processor, we are having a new mmu model
[1] that require us to maintain a different linux page table format.
Inorder to support both current and future ppc64 systems with a single
kernel we need to make sure kernel can select between different page
table format at runtime. With the new MMU (radix MMU) added, we will
have two different pmd hugepage size 16MB for hash model and 2MB for
Radix model. Hence make HPAGE_PMD related values as a variable.
Actual conversion of HPAGE_PMD to a variable for ppc64 happens in a
followup patch.
[1] http://ibm.biz/power-isa3 (Needs registration).
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Introduce compiletime_assert to compiler.h, which moves the details of
how to break a build and emit an error message for a specific compiler
to the headers where these details should be. Following in the
tradition of the POSIX assert macro, compiletime_assert creates a
build-time error when the supplied condition is *false*.
Next, we add BUILD_BUG_ON_MSG to bug.h which simply wraps
compiletime_assert, inverting the logic, so that it fails when the
condition is *true*, consistent with the language "build bug on." This
macro allows you to specify the error message you want emitted when the
supplied condition is true.
Finally, we remove all other code from bug.h that mucks with these
details (BUILD_BUG & BUILD_BUG_ON), and have them all call
BUILD_BUG_ON_MSG. This not only reduces source code bloat, but also
prevents the possibility of code being changed for one macro and not for
the other (which was previously the case for BUILD_BUG and
BUILD_BUG_ON).
Since __compiletime_error_fallback is now only used in compiler.h, I'm
considering it a private macro and removing the double negation that's
now extraneous.
[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Joe Perches <joe@perches.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Prior to the introduction of __attribute__((error("msg"))) in gcc 4.3,
creating compile-time errors required a little trickery.
BUILD_BUG{,_ON} uses this attribute when available to generate
compile-time errors, but also uses the negative-sized array trick for
older compilers, resulting in two error messages in some cases. The
reason it's "some" cases is that as of gcc 4.4, the negative-sized array
will not create an error in some situations, like inline functions.
This patch replaces the negative-sized array code with the new
__compiletime_error_fallback() macro which expands to the same thing
unless the the error attribute is available, in which case it expands to
do{}while(0), resulting in exactly one compile-time error on all
versions of gcc.
Note that we are not changing the negative-sized array code for the
unoptimized version of BUILD_BUG_ON, since it has the potential to catch
problems that would be disabled in later versions of gcc were
__compiletime_error_fallback used. The reason is that that an
unoptimized build can't always remove calls to an error-attributed
function call (like we are using) that should effectively become dead
code if it were optimized. However, using a negative-sized array with a
similar value will not result in an false-positive (error). The only
caveat being that it will also fail to catch valid conditions, which we
should be expecting in an unoptimized build anyway.
Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Joe Perches <joe@perches.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Negative sized arrays wont create a compile-time error in some cases
starting with gcc 4.4 (e.g., inlined functions), but gcc 4.3 introduced
the error function attribute that will.
This patch modifies BUILD_BUG_ON to behave like BUILD_BUG already does,
using the error function attribute so that you don't have to build the
entire kernel to discover that you have a problem, and then enjoy trying
to track it down from a link-time error.
Also, we are only including asm/bug.h and then expecting that
linux/compiler.h will eventually be included to define __linktime_error
(used in BUILD_BUG_ON). This patch includes it directly for clarity and
to avoid the possibility of changes in <arch>/*/include/asm/bug.h being
changed or not including linux/compiler.h for some reason.
Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joe Perches <joe@perches.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When calling BUILD_BUG_ON in an optimized build using gcc 4.3 and later,
the condition will be evaulated twice, possibily with side-effects. This
patch eliminates that error.
[akpm@linux-foundation.org: tweak code layout]
Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Rientjes <rientjes@google.com>
Cc: Joe Perches <joe@perches.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When __CHECKER__ is defined, we disable all of the BUILD_BUG.* macros.
However, both BUILD_BUG_ON_NOT_POWER_OF_2 and BUILD_BUG_ON was evaluating
to nothing in this case, and we want (0) since this is a function-like
macro that will be followed by a semicolon.
Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joe Perches <joe@perches.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__linktime_error() does the same thing as __compiletime_error() and is
only used in bug.h. Since the macro defines a function attribute that
will cause a failure at compile-time (not link-time), it makes more sense
to keep __compiletime_error(), which is also neatly mated with
__compiletime_warning().
Signed-off-by: Daniel Santos <daniel.santos@pobox.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Joe Perches <joe@perches.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit baf05aa927 ("bug: introduce BUILD_BUG_ON_INVALID() macro")
introduces this macro only when _CHECKER_ is not defined. Define a
silent macro in the else condition to fix following sparse warning:
mm/filemap.c:395:9: error: undefined identifier 'BUILD_BUG_ON_INVALID'
mm/filemap.c:396:9: error: undefined identifier 'BUILD_BUG_ON_INVALID'
mm/filemap.c:397:9: error: undefined identifier 'BUILD_BUG_ON_INVALID'
include/linux/mm.h:419:9: error: undefined identifier 'BUILD_BUG_ON_INVALID'
include/linux/mm.h:419:9: error: not a function <noident>
Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Acked-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Sometimes we want to check some expressions correctness at compile time.
"(void)(e);" or "if (e);" can be dangerous if the expression has
side-effects, and gcc sometimes generates a lot of code, even if the
expression has no effect.
This patch introduces macro BUILD_BUG_ON_INVALID() for such checks, it
forces a compilation error if expression is invalid without any extra
code.
[Cast to "long" required because sizeof does not work for bit-fields.]
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The support for BUILD_BUG in linux/kernel.h predates the
addition of linux/bug.h -- with this chunk off separate,
you can run into situations where a person gets a compile
fail even when they've included linux/bug.h, like this:
CC lib/string.o
lib/string.c: In function 'strlcat':
lib/string.c:225:2: error: implicit declaration of function 'BUILD_BUG_ON'
make[2]: *** [lib/string.o] Error 1
$
$ grep linux/bug.h lib/string.c
#include <linux/bug.h>
$
Since the above violates the principle of least surprise, move
the BUG chunks from kernel.h to bug.h so it is all together.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
They're in linux/bug.h at present, which causes include order tangles. In
particular, linux/bug.h cannot be used by linux/atomic.h because,
according to Nikanth:
linux/bug.h pulls in linux/module.h => linux/spinlock.h => asm/spinlock.h
(which uses atomic_inc) => asm/atomic.h.
bug.h is a pretty low-level thing and module.h is a higher-level thing,
IMO.
Cc: Nikanth Karthikesan <knikanth@novell.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current generic bug implementation has a call to dump_stack() in case a
WARN_ON(whatever) gets hit. Since report_bug(), which calls dump_stack(),
gets called from an exception handler we can do better: just pass the
pt_regs structure to report_bug() and pass it to show_regs() in case of a
warning. This will give more debug informations like register contents,
etc... In addition this avoids some pointless lines that dump_stack()
emits, since it includes a stack backtrace of the exception handler which
is of no interest in case of a warning. E.g. on s390 the following lines
are currently always present in a stack backtrace if dump_stack() gets
called from report_bug():
[<000000000001517a>] show_trace+0x92/0xe8)
[<0000000000015270>] show_stack+0xa0/0xd0
[<00000000000152ce>] dump_stack+0x2e/0x3c
[<0000000000195450>] report_bug+0x98/0xf8
[<0000000000016cc8>] illegal_op+0x1fc/0x21c
[<00000000000227d6>] sysc_return+0x0/0x10
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds common handling for kernel BUGs, for use by architectures as
they wish. The code is derived from arch/powerpc.
The advantages of having common BUG handling are:
- consistent BUG reporting across architectures
- shared implementation of out-of-line file/line data
- implement CONFIG_DEBUG_BUGVERBOSE consistently
This means that in inline impact of BUG is just the illegal instruction
itself, which is an improvement for i386 and x86-64.
A BUG is represented in the instruction stream as an illegal instruction,
which has file/line information associated with it. This extra information is
stored in the __bug_table section in the ELF file.
When the kernel gets an illegal instruction, it first confirms it might
possibly be from a BUG (ie, in kernel mode, the right illegal instruction).
It then calls report_bug(). This searches __bug_table for a matching
instruction pointer, and if found, prints the corresponding file/line
information. If report_bug() determines that it wasn't a BUG which caused the
trap, it returns BUG_TRAP_TYPE_NONE.
Some architectures (powerpc) implement WARN using the same mechanism; if the
illegal instruction was the result of a WARN, then report_bug(Q) returns
CONFIG_DEBUG_BUGVERBOSE; otherwise it returns BUG_TRAP_TYPE_BUG.
lib/bug.c keeps a list of loaded modules which can be searched for __bug_table
entries. The architecture must call
module_bug_finalize()/module_bug_cleanup() from its corresponding
module_finalize/cleanup functions.
Unsetting CONFIG_DEBUG_BUGVERBOSE will reduce the kernel size by some amount.
At the very least, filename and line information will not be recorded for each
but, but architectures may decide to store no extra information per BUG at
all.
Unfortunately, gcc doesn't have a general way to mark an asm() as noreturn, so
architectures will generally have to include an infinite loop (or similar) in
the BUG code, so that gcc knows execution won't continue beyond that point.
gcc does have a __builtin_trap() operator which may be useful to achieve the
same effect, unfortunately it cannot be used to actually implement the BUG
itself, because there's no way to get the instruction's address for use in
generating the __bug_table entry.
[randy.dunlap@oracle.com: Handle BUG=n, GENERIC_BUG=n to prevent build errors]
[bunk@stusta.de: include/linux/bug.h must always #include <linux/module.h]
Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Andi Kleen <ak@muc.de>
Cc: Hugh Dickens <hugh@veritas.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
