linux-stable.git/arch/um/include/shared, branch v5.19.2

um: seed rng using host OS rng

2022-08-17T13:13:53+00:00

commit 0b9ba6135d7f18b82f3d8bebb55ded725ba88e0e upstream.

UML generally does not provide access to special CPU instructions like
RDRAND, and execution tends to be rather deterministic, with no real
hardware interrupts, making good randomness really very hard, if not
all together impossible. Not only is this a security eyebrow raiser, but
it's also quite annoying when trying to do various pieces of UML-based
automation that takes a long time to boot, if ever.

Fix this by trivially calling getrandom() in the host and using that
seed as "bootloader randomness", which initializes the rng immediately
at UML boot.

The old behavior can be restored the same way as on any other arch, by
way of CONFIG_TRUST_BOOTLOADER_RANDOMNESS=n or
random.trust_bootloader=0. So seen from that perspective, this just
makes UML act like other archs, which is positive in its own right.

Additionally, wire up arch_get_random_{int,long}() in the same way, so
that reseeds can also make use of the host RNG, controllable by
CONFIG_TRUST_CPU_RANDOMNESS and random.trust_cpu, per usual.

Cc: stable@vger.kernel.org
Acked-by: Johannes Berg 
Acked-By: Anton Ivanov 
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

um: Replace to_phys() and to_virt() with less generic function names

2022-07-14T18:57:27+00:00

The UML function names to_virt() and to_phys() are exposed by UML
headers, and are very generic and may be defined by drivers.  As it
turns out, commit 9409c9b6709e ("pmem: refactor pmem_clear_poison()")
did exactly that.

This results in build errors such as the following when trying to build
um:allmodconfig:

  drivers/nvdimm/pmem.c: In function ‘pmem_dax_zero_page_range’:
  ./arch/um/include/asm/page.h:105:20: error: too few arguments to function ‘to_phys’
    105 | #define __pa(virt) to_phys((void *) (unsigned long) (virt))
        |                    ^~~~~~~

Use less generic function names for the um specific to_phys() and
to_virt() functions to fix the problem and to avoid similar problems in
the future.

Fixes: 9409c9b6709e ("pmem: refactor pmem_clear_poison()")
Cc: Dan Williams 
Cc: Christoph Hellwig 
Signed-off-by: Guenter Roeck 
Signed-off-by: Linus Torvalds

Merge tag 'for-linus-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

2022-03-31T23:16:58+00:00

Pull UML updates from Richard Weinberger:

 - Devicetree support (for testing)

 - Various cleanups and fixes: UBD, port_user, uml_mconsole

 - Maintainer update

* tag 'for-linus-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: run_helper: Write error message to kernel log on exec failure on host
  um: port_user: Improve error handling when port-helper is not found
  um: port_user: Allow setting path to port-helper using UML_PORT_HELPER envvar
  um: port_user: Search for in.telnetd in PATH
  um: clang: Strip out -mno-global-merge from USER_CFLAGS
  docs: UML: Mention telnetd for port channel
  um: Remove unused timeval_to_ns() function
  um: Fix uml_mconsole stop/go
  um: Cleanup syscall_handler_t definition/cast, fix warning
  uml: net: vector: fix const issue
  um: Fix WRITE_ZEROES in the UBD Driver
  um: Migrate vector drivers to NAPI
  um: Fix order of dtb unflatten/early init
  um: fix and optimize xor select template for CONFIG64 and timetravel mode
  um: Document dtb command line option
  lib/logic_iomem: correct fallback config references
  um: Remove duplicated include in syscalls_64.c
  MAINTAINERS: Update UserModeLinux entry

um: Fix WRITE_ZEROES in the UBD Driver

2022-03-11T09:46:34+00:00

Call to fallocate with FALLOC_FL_PUNCH_HOLE on a device backed by a sparse
file can end up by missing data, zeroes data range, if the underlying file
is used with a tool like bmaptool which will referenced only used spaces.

Signed-off-by: Frédéric Danis 
Acked-by: Anton Ivanov 
Signed-off-by: Richard Weinberger

treewide: Replace zero-length arrays with flexible-array members

2022-02-17T13:00:39+00:00

There is a regular need in the kernel to provide a way to declare
having a dynamically sized set of trailing elements in a structure.
Kernel code should always use “flexible array members”[1] for these
cases. The older style of one-element or zero-length arrays should
no longer be used[2].

This code was transformed with the help of Coccinelle:
(next-20220214$ spatch --jobs $(getconf _NPROCESSORS_ONLN) --sp-file script.cocci --include-headers --dir . > output.patch)

@@
identifier S, member, array;
type T1, T2;
@@

struct S {
  ...
  T1 member;
  T2 array[
- 0
  ];
};

UAPI and wireless changes were intentionally excluded from this patch
and will be sent out separately.

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/78
Reviewed-by: Kees Cook 
Signed-off-by: Gustavo A. R. Silva

um: header debriding - sigio.h

2021-12-21T20:31:36+00:00

Signed-off-by: Al Viro 
Signed-off-by: Richard Weinberger

um: header debriding - os.h

2021-12-21T20:31:36+00:00

Signed-off-by: Al Viro 
Signed-off-by: Richard Weinberger

um: header debriding - net_*.h

2021-12-21T20:31:35+00:00

externs dead since before the initial merge

Signed-off-by: Al Viro 
Signed-off-by: Richard Weinberger

um: header debriding - mem_user.h

2021-12-21T20:31:35+00:00

get_vm(), add_iomem(), phys_offset() dead since 2004;
init_mem_user() and setup_memory() - since before the initial merge.

Signed-off-by: Al Viro 
Signed-off-by: Richard Weinberger

um: header debriding - activate_ipi()

2021-12-21T20:31:35+00:00

... had been dead for 15 years.

Signed-off-by: Al Viro 
Signed-off-by: Richard Weinberger