Go to file
Saurabh Sengar bb9b0e46b8 hv: hyperv.h: Replace one-element array with flexible-array member
One-element and zero-length arrays are deprecated. Replace one-element
array in struct vmtransfer_page_packet_header with flexible-array
member. This change fixes below warning:

[    2.593788] ================================================================================
[    2.593908] UBSAN: array-index-out-of-bounds in drivers/net/hyperv/netvsc.c:1445:41
[    2.593989] index 1 is out of range for type 'vmtransfer_page_range [1]'
[    2.594049] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.5.0-rc4-next-20230803+ #1
[    2.594114] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 04/20/2023
[    2.594121] Call Trace:
[    2.594126]  <IRQ>
[    2.594133]  dump_stack_lvl+0x4c/0x70
[    2.594154]  dump_stack+0x14/0x20
[    2.594162]  __ubsan_handle_out_of_bounds+0xa6/0xf0
[    2.594224]  netvsc_poll+0xc01/0xc90 [hv_netvsc]
[    2.594258]  __napi_poll+0x30/0x1e0
[    2.594320]  net_rx_action+0x194/0x2f0
[    2.594333]  __do_softirq+0xde/0x31e
[    2.594345]  __irq_exit_rcu+0x6b/0x90
[    2.594357]  irq_exit_rcu+0x12/0x20
[    2.594366]  sysvec_hyperv_callback+0x84/0x90
[    2.594376]  </IRQ>
[    2.594379]  <TASK>
[    2.594383]  asm_sysvec_hyperv_callback+0x1f/0x30
[    2.594394] RIP: 0010:pv_native_safe_halt+0xf/0x20
[    2.594452] Code: 0b 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 05 35 3f 00 fb f4 <c3> cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
[    2.594459] RSP: 0018:ffffb841c00d3e88 EFLAGS: 00000256
[    2.594469] RAX: ffff9d18c326f4a0 RBX: ffff9d18c031df40 RCX: 4000000000000000
[    2.594475] RDX: 0000000000000001 RSI: 0000000000000082 RDI: 00000000000268dc
[    2.594481] RBP: ffffb841c00d3e90 R08: 00000066a171109b R09: 00000000d33d2600
[    2.594486] R10: 000000009a41bf00 R11: 0000000000000000 R12: 0000000000000001
[    2.594491] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[    2.594501]  ? ct_kernel_exit.constprop.0+0x7d/0x90
[    2.594513]  ? default_idle+0xd/0x20
[    2.594523]  arch_cpu_idle+0xd/0x20
[    2.594532]  default_idle_call+0x30/0xe0
[    2.594542]  do_idle+0x200/0x240
[    2.594553]  ? complete+0x71/0x80
[    2.594613]  cpu_startup_entry+0x24/0x30
[    2.594624]  start_secondary+0x12d/0x160
[    2.594634]  secondary_startup_64_no_verify+0x17e/0x18b
[    2.594649]  </TASK>
[    2.594656] ================================================================================

With this change the structure size is reduced by 8 bytes, below is the
pahole output.

struct vmtransfer_page_packet_header {
	struct vmpacket_descriptor d;                    /*     0    16 */
	u16                        xfer_pageset_id;      /*    16     2 */
	u8                         sender_owns_set;      /*    18     1 */
	u8                         reserved;             /*    19     1 */
	u32                        range_cnt;            /*    20     4 */
	struct vmtransfer_page_range ranges[];           /*    24     0 */

	/* size: 24, cachelines: 1, members: 6 */
	/* last cacheline: 24 bytes */
};

The validation code in the netvsc driver is affected by changing the
struct size, but the effects have been examined and have been determined
to be appropriate.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/1692160478-18469-1-git-send-email-ssengar@linux.microsoft.com
2023-08-22 01:19:47 +00:00
Documentation TTY/Serial fixes for 6.5-rc4 2023-07-30 11:51:36 -07:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
arch x86/hyperv: Add hyperv-specific handling for VMMCALL under SEV-ES 2023-08-22 00:38:20 +00:00
block block-6.5-2023-07-21 2023-07-22 11:05:15 -07:00
certs KEYS: Add missing function documentation 2023-04-24 16:15:52 +03:00
crypto crypto: algif_hash - Fix race between MORE and non-MORE sends 2023-07-08 22:48:42 +10:00
drivers Drivers: hv: vmbus: Don't dereference ACPI root object handle 2023-08-22 01:18:32 +00:00
fs four small client fixes 2023-07-29 20:49:13 -07:00
include hv: hyperv.h: Replace one-element array with flexible-array member 2023-08-22 01:19:47 +00:00
init Kbuild updates for v6.5 2023-07-01 09:24:31 -07:00
io_uring io_uring-6.5-2023-07-28 2023-07-28 10:19:44 -07:00
ipc Merge branch 'work.namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2023-02-24 19:20:07 -08:00
kernel Probe fixes for 6.5-rc3: 2023-07-30 11:27:22 -07:00
lib Char driver and Documentation fixes for 6.5-rc4 2023-07-30 11:44:00 -07:00
mm 11 hotfixes. Five are cc:stable and the remainder address post-6.4 issues 2023-07-28 17:19:52 -07:00
net A patch to reduce the potential for erroneous RBD exclusive lock 2023-07-28 10:47:24 -07:00
rust rust: error: `impl Debug` for `Error` with `errname()` integration 2023-06-13 01:24:42 +02:00
samples arm64: ftrace: Add direct call trampoline samples support 2023-07-10 17:51:54 -04:00
scripts x86: 2023-07-30 11:19:08 -07:00
security security: keys: perform capable check only on privileged operations 2023-07-28 18:07:41 +00:00
sound ASoC: Fixes for v6.5 2023-07-27 14:54:23 +02:00
tools Probe fixes for 6.5-rc3: 2023-07-30 11:27:22 -07:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt KVM: Grab a reference to KVM for VM and vCPU stats file descriptors 2023-07-29 11:05:28 -04:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Revert ".gitignore: ignore *.cover and *.mbx" 2023-07-04 15:05:12 -07:00
.mailmap mailmap: update remaining active codeaurora.org email addresses 2023-07-27 13:07:05 -07:00
.rustfmt.toml rust: add `.rustfmt.toml` 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS - Address -Wmissing-prototype warnings 2023-06-26 16:43:54 -07:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS USB fixes for 6.5-rc4 2023-07-30 11:57:51 -07:00
Makefile Linux 6.5-rc4 2023-07-30 13:23:47 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.