When the au_ralign field was added to gss_unwrap_resp_priv, the
wrong calculation was used. Setting au_rslack == au_ralign is
probably correct for kerberos_v1 privacy, but kerberos_v2 privacy
adds additional GSS data after the clear text RPC message.
au_ralign needs to be smaller than au_rslack in that fairly common
case.
When xdr_buf_trim() is restored to gss_unwrap_kerberos_v2(), it does
exactly what I feared it would: it trims off part of the clear text
RPC message. However, that's because rpc_prepare_reply_pages() does
not set up the rq_rcv_buf's tail correctly because au_ralign is too
large.
Fixing the au_ralign computation also corrects the alignment of
rq_rcv_buf->pages so that the client does not have to shift reply
data payloads after they are received.
Fixes: 35e77d21ba ("SUNRPC: Add rpc_auth::au_ralign field")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Refactor: This is a pre-requisite to fixing the client-side ralign
computation in gss_unwrap_resp_priv().
The length value is passed in explicitly rather that as the value
of buf->len. This will subsequently allow gss_unwrap_kerberos_v1()
to compute a slack and align value, instead of computing it in
gss_unwrap_resp_priv().
Fixes: 35e77d21ba ("SUNRPC: Add rpc_auth::au_ralign field")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Pull staging/IIO driver fixes from Greg KH:
"Here are some small staging and IIO driver fixes for 5.7-rc3
Lots of tiny things for reported issues in staging and IIO drivers,
including a counter driver fix as well (the iio drivers seem to be
tied to those). Full details of the fixes are in the shortlog.
All of these have been in linux-next for a while with no reported
issues"
* tag 'staging-5.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (27 commits)
staging: vt6656: Fix calling conditions of vnt_set_bss_mode
staging: comedi: Fix comedi_device refcnt leak in comedi_open
staging: vt6656: Fix pairwise key entry save.
staging: vt6656: Fix drivers TBTT timing counter.
staging: vt6656: Don't set RCR_MULTICAST or RCR_BROADCAST by default.
MAINTAINERS: remove Stefan Popa's email
iio: adc: ad7192: fix null pointer de-reference crash during probe
iio: core: remove extra semi-colon from devm_iio_device_register() macro
iio: adc: ti-ads8344: properly byte swap value
iio: imu: inv_mpu6050: fix suspend/resume with runtime power
iio: st_sensors: rely on odr mask to know if odr can be set
iio: xilinx-xadc: Make sure not exceed maximum samplerate
iio: xilinx-xadc: Fix sequencer configuration for aux channels in simultaneous mode
iio: xilinx-xadc: Fix clearing interrupt when enabling trigger
iio: xilinx-xadc: Fix ADC-B powerdown
iio: dac: ad5770r: fix off-by-one check on maximum number of channels
iio: imu: st_lsm6dsx: flush hw FIFO before resetting the device
iio: core: Fix handling of 'dB'
dt-bindings: iio: adc: stm32-adc: fix id relative path
counter: 104-quad-8: Add lock guards - generic interface
...
Pull driver core fixes from Greg KH:
"Here are some small firmware/driver core/debugfs fixes for 5.7-rc3.
The debugfs change is now possible as now the last users of
debugfs_create_u32() have been fixed up in the different trees that
got merged into 5.7-rc1, and I don't want it creeping back in.
The firmware changes did cause a regression in linux-next, so the
final patch here reverts part of that, re-exporting the symbol to
resolve that issue. All of these patches, with the exception of the
final one, have been in linux-next with only that one reported issue"
* tag 'driver-core-5.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
firmware_loader: revert removal of the fw_fallback_config export
debugfs: remove return value of debugfs_create_u32()
firmware_loader: remove unused exports
firmware: imx: fix compile-testing
Pull networking fixes from David Miller:
1) Fix memory leak in netfilter flowtable, from Roi Dayan.
2) Ref-count leaks in netrom and tipc, from Xiyu Yang.
3) Fix warning when mptcp socket is never accepted before close, from
Florian Westphal.
4) Missed locking in ovs_ct_exit(), from Tonghao Zhang.
5) Fix large delays during PTP synchornization in cxgb4, from Rahul
Lakkireddy.
6) team_mode_get() can hang, from Taehee Yoo.
7) Need to use kvzalloc() when allocating fw tracer in mlx5 driver,
from Niklas Schnelle.
8) Fix handling of bpf XADD on BTF memory, from Jann Horn.
9) Fix BPF_STX/BPF_B encoding in x86 bpf jit, from Luke Nelson.
10) Missing queue memory release in iwlwifi pcie code, from Johannes
Berg.
11) Fix NULL deref in macvlan device event, from Taehee Yoo.
12) Initialize lan87xx phy correctly, from Yuiko Oshino.
13) Fix looping between VRF and XFRM lookups, from David Ahern.
14) etf packet scheduler assumes all sockets are full sockets, which is
not necessarily true. From Eric Dumazet.
15) Fix mptcp data_fin handling in RX path, from Paolo Abeni.
16) fib_select_default() needs to handle nexthop objects, from David
Ahern.
17) Use GFP_ATOMIC under spinlock in mac80211_hwsim, from Wei Yongjun.
18) vxlan and geneve use wrong nlattr array, from Sabrina Dubroca.
19) Correct rx/tx stats in bcmgenet driver, from Doug Berger.
20) BPF_LDX zero-extension is encoded improperly in x86_32 bpf jit, fix
from Luke Nelson.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (100 commits)
selftests/bpf: Fix a couple of broken test_btf cases
tools/runqslower: Ensure own vmlinux.h is picked up first
bpf: Make bpf_link_fops static
bpftool: Respect the -d option in struct_ops cmd
selftests/bpf: Add test for freplace program with expected_attach_type
bpf: Propagate expected_attach_type when verifying freplace programs
bpf: Fix leak in LINK_UPDATE and enforce empty old_prog_fd
bpf, x86_32: Fix logic error in BPF_LDX zero-extension
bpf, x86_32: Fix clobbering of dst for BPF_JSET
bpf, x86_32: Fix incorrect encoding in BPF_LDX zero-extension
bpf: Fix reStructuredText markup
net: systemport: suppress warnings on failed Rx SKB allocations
net: bcmgenet: suppress warnings on failed Rx SKB allocations
macsec: avoid to set wrong mtu
mac80211: sta_info: Add lockdep condition for RCU list usage
mac80211: populate debugfs only after cfg80211 init
net: bcmgenet: correct per TX/RX ring statistics
net: meth: remove spurious copyright text
net: phy: bcm84881: clear settings on link down
chcr: Fix CPU hard lockup
...
Pull PNP cleanup from Rafael Wysocki:
"Make the PNP code use list_for_each_entry() in a few places instead of
open-coding it (Jason Gunthorpe)"
* tag 'pnp-5.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
pnp: Use list_for_each_entry() instead of open coding
Pull block fixes from Jens Axboe:
"A few fixes/changes that should go into this release:
- null_blk zoned fixes (Damien)
- blkdev_close() sync improvement (Douglas)
- Fix regression in blk-iocost that impacted (at least) systemtap
(Waiman)
- Comment fix, header removal (Zhiqiang, Jianpeng)"
* tag 'block-5.7-2020-04-24' of git://git.kernel.dk/linux-block:
null_blk: Cleanup zoned device initialization
null_blk: Fix zoned command handling
block: remove unused header
blk-iocost: Fix error on iocost_ioc_vrate_adj
bdev: Reduce time holding bd_mutex in sync in blkdev_close()
buffer: remove useless comment and WB_REASON_FREE_MORE_MEM, reason.
Pull tracing fixes from Steven Rostedt:
"A few tracing fixes:
- Two fixes for memory leaks detected by kmemleak
- Removal of some dead code
- A few local functions turned static"
* tag 'trace-v5.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Convert local functions in tracing_map.c to static
tracing: Remove DECLARE_TRACE_NOARGS
ftrace: Fix memory leak caused by not freeing entry in unregister_ftrace_direct()
tracing: Fix memory leaks in trace_events_hist.c
Pull Kbuild fixes from Masahiro Yamada:
- fix scripts/config to properly handle ':' in string type CONFIG
options
- fix unneeded rebuilds of DT schema check rule
- git rid of ordering dependency between <linux/vermagic.h> and
<linux/module.h> to fix build errors in some network drivers
- clean up generated headers of host arch with 'make ARCH=um mrproper'
* tag 'kbuild-fixes-v5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
h8300: ignore vmlinux.lds
Documentation: kbuild: fix the section title format
um: ensure `make ARCH=um mrproper` removes arch/$(SUBARCH)/include/generated/
arch: split MODULE_ARCH_VERMAGIC definitions out to <asm/vermagic.h>
kbuild: fix DT binding schema rule again to avoid needless rebuilds
scripts/config: allow colons in option strings for sed
Pull nfsd fixes from Chuck Lever:
"The first set of 5.7-rc fixes for NFS server issues.
These were all unresolved at the time the 5.7 window opened, and
needed some additional time to ensure they were correctly addressed.
They are ready now.
At the moment I know of one more urgent issue regarding the NFS
server. A fix has been tested and is under review. I expect to send
one more pull request, containing this fix (which now consists of 3
patches).
Fixes:
- Address several use-after-free and memory leak bugs
- Prevent a backchannel livelock"
* tag 'nfsd-5.7-rc-1' of git://git.linux-nfs.org/projects/cel/cel-2.6:
svcrdma: Fix leak of svc_rdma_recv_ctxt objects
svcrdma: Fix trace point use-after-free race
SUNRPC: Fix backchannel RPC soft lockups
SUNRPC/cache: Fix unsafe traverse caused double-free in cache_purge
nfsd: memory corruption in nfsd4_lock()
As the bug report [1] pointed out, <linux/vermagic.h> must be included
after <linux/module.h>.
I believe we should not impose any include order restriction. We often
sort include directives alphabetically, but it is just coding style
convention. Technically, we can include header files in any order by
making every header self-contained.
Currently, arch-specific MODULE_ARCH_VERMAGIC is defined in
<asm/module.h>, which is not included from <linux/vermagic.h>.
Hence, the straight-forward fix-up would be as follows:
|--- a/include/linux/vermagic.h
|+++ b/include/linux/vermagic.h
|@@ -1,5 +1,6 @@
| /* SPDX-License-Identifier: GPL-2.0 */
| #include <generated/utsrelease.h>
|+#include <linux/module.h>
|
| /* Simply sanity version stamp for modules. */
| #ifdef CONFIG_SMP
This works enough, but for further cleanups, I split MODULE_ARCH_VERMAGIC
definitions into <asm/vermagic.h>.
With this, <linux/module.h> and <linux/vermagic.h> will be orthogonal,
and the location of MODULE_ARCH_VERMAGIC definitions will be consistent.
For arc and ia64, MODULE_PROC_FAMILY is only used for defining
MODULE_ARCH_VERMAGIC. I squashed it.
For hexagon, nds32, and xtensa, I removed <asm/modules.h> entirely
because they contained nothing but MODULE_ARCH_VERMAGIC definition.
Kbuild will automatically generate <asm/modules.h> at build-time,
wrapping <asm-generic/module.h>.
[1] https://lore.kernel.org/lkml/20200411155623.GA22175@zn.tnic
Reported-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Aside from good practice, this avoids a warning from gcc 10:
./include/linux/kernel.h:997:3: warning: array subscript -31 is outside array bounds of ‘struct list_head[1]’ [-Warray-bounds]
997 | ((type *)(__mptr - offsetof(type, member))); })
| ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
./include/linux/list.h:493:2: note: in expansion of macro ‘container_of’
493 | container_of(ptr, type, member)
| ^~~~~~~~~~~~
./include/linux/pnp.h:275:30: note: in expansion of macro ‘list_entry’
275 | #define global_to_pnp_dev(n) list_entry(n, struct pnp_dev, global_list)
| ^~~~~~~~~~
./include/linux/pnp.h:281:11: note: in expansion of macro ‘global_to_pnp_dev’
281 | (dev) != global_to_pnp_dev(&pnp_global); \
| ^~~~~~~~~~~~~~~~~
arch/x86/kernel/rtc.c:189:2: note: in expansion of macro ‘pnp_for_each_dev’
189 | pnp_for_each_dev(dev) {
Because the common code doesn't cast the starting list_head to the
containing struct.
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
[ rjw: Whitespace adjustments ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This patch is to enable Intel SERDES power up/down sequence. The SERDES
converts 8/10 bits data to SGMII signal. Below is an example of
HW configuration for SGMII mode. The SERDES is located in the PHY IF
in the diagram below.
<-----------------GBE Controller---------->|<--External PHY chip-->
+----------+ +----+ +---+ +----------+
| EQoS | <-GMII->| DW | < ------ > |PHY| <-SGMII-> | External |
| MAC | |xPCS| |IF | | PHY |
+----------+ +----+ +---+ +----------+
^ ^ ^ ^
| | | |
+---------------------MDIO-------------------------+
PHY IF configuration and status registers are accessible through
mdio address 0x15 which is defined as mdio_adhoc_addr. During D0,
The driver will need to power up PHY IF by changing the power state
to P0. Likewise, for D3, the driver sets PHY IF power state to P3.
Signed-off-by: Voon Weifeng <weifeng.voon@intel.com>
Signed-off-by: Ong Boon Leong <boon.leong.ong@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge misc fixes from Andrew Morton:
"15 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
tools/vm: fix cross-compile build
coredump: fix null pointer dereference on coredump
mm: shmem: disable interrupt when acquiring info->lock in userfaultfd_copy path
shmem: fix possible deadlocks on shmlock_user_lock
vmalloc: fix remap_vmalloc_range() bounds checks
mm/shmem: fix build without THP
mm/ksm: fix NULL pointer dereference when KSM zero page is enabled
tools/build: tweak unused value workaround
checkpatch: fix a typo in the regex for $allocFunctions
mm, gup: return EINTR when gup is interrupted by fatal signals
mm/hugetlb: fix a addressing exception caused by huge_pte_offset
MAINTAINERS: add an entry for kfifo
mm/userfaultfd: disable userfaultfd-wp on x86_32
slub: avoid redzone when choosing freepointer location
sh: fix build error in mm/init.c
Pull kvm fixes from Paolo Bonzini:
"Bugfixes, and a few cleanups to the newly-introduced assembly language
vmentry code for AMD"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: PPC: Book3S HV: Handle non-present PTEs in page fault functions
kvm: Disable objtool frame pointer checking for vmenter.S
MAINTAINERS: add a reviewer for KVM/s390
KVM: s390: Fix PV check in deliverable_irqs()
kvm: Handle reads of SandyBridge RAPL PMU MSRs rather than injecting #GP
KVM: Remove CREATE_IRQCHIP/SET_PIT2 race
KVM: SVM: Fix __svm_vcpu_run declaration.
KVM: SVM: Do not setup frame pointer in __svm_vcpu_run
KVM: SVM: Fix build error due to missing release_pages() include
KVM: SVM: Do not mark svm_vcpu_run with STACK_FRAME_NON_STANDARD
kvm: nVMX: match comment with return type for nested_vmx_exit_reflected
kvm: nVMX: reflect MTF VM-exits if injected by L1
KVM: s390: Return last valid slot if approx index is out-of-bounds
KVM: Check validity of resolved slot when searching memslots
KVM: VMX: Enable machine check support for 32bit targets
KVM: SVM: move more vmentry code to assembly
KVM: SVM: fix compilation with modular PSP and non-modular KVM
Pull virtio fixes and cleanups from Michael Tsirkin:
- Some bug fixes
- Cleanup a couple of issues that surfaced meanwhile
- Disable vhost on ARM with OABI for now - to be fixed fully later in
the cycle or in the next release.
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (24 commits)
vhost: disable for OABI
virtio: drop vringh.h dependency
virtio_blk: add a missing include
virtio-balloon: Avoid using the word 'report' when referring to free page hinting
virtio-balloon: make virtballoon_free_page_report() static
vdpa: fix comment of vdpa_register_device()
vdpa: make vhost, virtio depend on menu
vdpa: allow a 32 bit vq alignment
drm/virtio: fix up for include file changes
remoteproc: pull in slab.h
rpmsg: pull in slab.h
virtio_input: pull in slab.h
remoteproc: pull in slab.h
virtio-rng: pull in slab.h
virtgpu: pull in uaccess.h
tools/virtio: make asm/barrier.h self contained
tools/virtio: define aligned attribute
virtio/test: fix up after IOTLB changes
vhost: Create accessors for virtqueues private_data
vdpasim: Return status in vdpasim_get_status
...
remap_vmalloc_range() has had various issues with the bounds checks it
promises to perform ("This function checks that addr is a valid
vmalloc'ed area, and that it is big enough to cover the vma") over time,
e.g.:
- not detecting pgoff<<PAGE_SHIFT overflow
- not detecting (pgoff<<PAGE_SHIFT)+usize overflow
- not checking whether addr and addr+(pgoff<<PAGE_SHIFT) are the same
vmalloc allocation
- comparing a potentially wildly out-of-bounds pointer with the end of
the vmalloc region
In particular, since commit fc9702273e ("bpf: Add mmap() support for
BPF_MAP_TYPE_ARRAY"), unprivileged users can cause kernel null pointer
dereferences by calling mmap() on a BPF map with a size that is bigger
than the distance from the start of the BPF map to the end of the
address space.
This could theoretically be used as a kernel ASLR bypass, by using
whether mmap() with a given offset oopses or returns an error code to
perform a binary search over the possible address range.
To allow remap_vmalloc_range_partial() to verify that addr and
addr+(pgoff<<PAGE_SHIFT) are in the same vmalloc region, pass the offset
to remap_vmalloc_range_partial() instead of adding it to the pointer in
remap_vmalloc_range().
In remap_vmalloc_range_partial(), fix the check against
get_vm_area_size() by using size comparisons instead of pointer
comparisons, and add checks for pgoff.
Fixes: 833423143c ("[PATCH] mm: introduce remap_vmalloc_range()")
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@chromium.org>
Link: http://lkml.kernel.org/r/20200415222312.236431-1-jannh@google.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jonathan writes:
First set of IIO fixes for the 5.7 cycle.
Includes one MAINTAINERS update to avoid people getting a lot of bounce
messages and complaining about it.
* MAINTAINERS
- Drop Stefan Popa's Analog Devices email address in favour of
Michael Hennerich.
* core
- Fix handling of dB sysfs inputs.
- Drop a stray semi colon in macro definition.
* ad5770r
- Fix an off by one in chec on maximum number of channels.
* ad7192
- Fix a null pointer de-reference due to the name previously being
retrieved from the spi_get_device_id call which no longer works as
the relevant table was removed.
* ad7797
- Use correct attribute group.
* counter/104-quad-8
- Add locks to prevent some race conditions.
* inv-mpu6050
- Fix issues around suspend / resume clashing with runtime PM.
* stm32-adc
- Fix sleep in invalid context
- Fix id relative path error in device tree binding doc.
* st_lsm6dsx
- Fix a read alignment issue on an untagged FIFO.
- Handle odr for slave to properly compute the FIFO data layout / pattern.
- Flush the HW FIFO before resettting the device to avoid a race on
interrupt line 1.
* st_sensors
- Rely on ODR mask not ODR address to identify if the ODR can be set.
Some devices have an ODR address of 0.
* ti-ads8344
- Byte ordering was wrong - fix it.
* xilinx-xadc
- Fix inverted logic in powering down the second ADC.
- Fix clearing interrupt when enabling the trigger.
- Fix configuration of sequencer when in simultaneous sampling mode.
- Limit initial sampling rate as done for runtime configured ones.
* tag 'iio-fixes-for-5.7a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio:
MAINTAINERS: remove Stefan Popa's email
iio: adc: ad7192: fix null pointer de-reference crash during probe
iio: core: remove extra semi-colon from devm_iio_device_register() macro
iio: adc: ti-ads8344: properly byte swap value
iio: imu: inv_mpu6050: fix suspend/resume with runtime power
iio: st_sensors: rely on odr mask to know if odr can be set
iio: xilinx-xadc: Make sure not exceed maximum samplerate
iio: xilinx-xadc: Fix sequencer configuration for aux channels in simultaneous mode
iio: xilinx-xadc: Fix clearing interrupt when enabling trigger
iio: xilinx-xadc: Fix ADC-B powerdown
iio: dac: ad5770r: fix off-by-one check on maximum number of channels
iio: imu: st_lsm6dsx: flush hw FIFO before resetting the device
iio: core: Fix handling of 'dB'
dt-bindings: iio: adc: stm32-adc: fix id relative path
counter: 104-quad-8: Add lock guards - generic interface
iio: imu: st_lsm6dsx: specify slave odr in slv_odr
iio: imu: st_lsm6dsx: fix read misalignment on untagged FIFO
iio: adc: stm32-adc: fix sleep in atomic context
iio:ad7797: Use correct attribute_group
Pull irq fixes from Thomas Gleixner:
"A set of fixes/updates for the interrupt subsystem:
- Remove setup_irq() and remove_irq(). All users have been converted
so remove them before new users surface.
- A set of bugfixes for various interrupt chip drivers
- Add a few missing static attributes to address sparse warnings"
* tag 'irq-urgent-2020-04-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/irq-bcm7038-l1: Make bcm7038_l1_of_init() static
irqchip/irq-mvebu-icu: Make legacy_bindings static
irqchip/meson-gpio: Fix HARDIRQ-safe -> HARDIRQ-unsafe lock order
irqchip/sifive-plic: Fix maximum priority threshold value
irqchip/ti-sci-inta: Fix processing of masked irqs
irqchip/mbigen: Free msi_desc on device teardown
irqchip/gic-v4.1: Update effective affinity of virtual SGIs
irqchip/gic-v4.1: Add support for VPENDBASER's Dirty+Valid signaling
genirq: Remove setup_irq() and remove_irq()
Pull ext4 fixes from Ted Ts'o:
"Miscellaneous bug fixes and cleanups for ext4, including a fix for
generic/388 in data=journal mode, removing some BUG_ON's, and cleaning
up some compiler warnings"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: convert BUG_ON's to WARN_ON's in mballoc.c
ext4: increase wait time needed before reuse of deleted inode numbers
ext4: remove set but not used variable 'es' in ext4_jbd2.c
ext4: remove set but not used variable 'es'
ext4: do not zeroout extents beyond i_disksize
ext4: fix return-value types in several function comments
ext4: use non-movable memory for superblock readahead
ext4: use matching invalidatepage in ext4_writepage
Pull flexible-array member conversion from Gustavo Silva:
"The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array
member[1][2], introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof
operator may not be applied. As a quirk of the original
implementation of zero-length arrays, sizeof evaluates to zero."[1]
sizeof(flexible-array-member) triggers a warning because flexible
array members have incomplete type[1]. There are some instances of
code in which the sizeof operator is being incorrectly/erroneously
applied to zero-length arrays and the result is zero. Such instances
may be hiding some bugs. So, this work (flexible-array member
convertions) will also help to get completely rid of those sorts of
issues.
Notice that all of these patches have been baking in linux-next for
quite a while now and, 238 more of these patches have already been
merged into 5.7-rc1.
There are a couple hundred more of these issues waiting to be
addressed in the whole codebase"
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
* tag 'flexible-array-member-5.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux: (28 commits)
xattr.h: Replace zero-length array with flexible-array member
uapi: linux: fiemap.h: Replace zero-length array with flexible-array member
uapi: linux: dlm_device.h: Replace zero-length array with flexible-array member
tpm_eventlog.h: Replace zero-length array with flexible-array member
ti_wilink_st.h: Replace zero-length array with flexible-array member
swap.h: Replace zero-length array with flexible-array member
skbuff.h: Replace zero-length array with flexible-array member
sched: topology.h: Replace zero-length array with flexible-array member
rslib.h: Replace zero-length array with flexible-array member
rio.h: Replace zero-length array with flexible-array member
posix_acl.h: Replace zero-length array with flexible-array member
platform_data: wilco-ec.h: Replace zero-length array with flexible-array member
memcontrol.h: Replace zero-length array with flexible-array member
list_lru.h: Replace zero-length array with flexible-array member
lib: cpu_rmap: Replace zero-length array with flexible-array member
irq.h: Replace zero-length array with flexible-array member
ihex.h: Replace zero-length array with flexible-array member
igmp.h: Replace zero-length array with flexible-array member
genalloc.h: Replace zero-length array with flexible-array member
ethtool.h: Replace zero-length array with flexible-array member
...
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
