Commit Graph

183 Commits

Author SHA1 Message Date
Tiwei Bie
fe6abeba24 um: Remove the declaration of user_thread function
This function has never been defined since its declaration was
introduced by commit 1da177e4c3 ("Linux-2.6.12-rc2").

Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2024-09-12 20:43:26 +02:00
Tiwei Bie
59376fb2a7 um: Remove unused mm_fd field from mm_id
It's no longer used since the removal of the SKAS3/4 support.

Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2024-09-12 20:36:22 +02:00
Gaosheng Cui
2df8c8d118 um: Remove obsoleted declaration for execute_syscall_skas
The execute_syscall_skas() have been removed since
commit e32dacb9f4 ("[PATCH] uml: system call path cleanup"),
and now it is useless, so remove it.

Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
2024-09-12 20:23:33 +02:00
Benjamin Berg
bcf3d957c6 um: refactor TLB update handling
Conceptually, we want the memory mappings to always be up to date and
represent whatever is in the TLB. To ensure that, we need to sync them
over in the userspace case and for the kernel we need to process the
mappings.

The kernel will call flush_tlb_* if page table entries that were valid
before become invalid. Unfortunately, this is not the case if entries
are added.

As such, change both flush_tlb_* and set_ptes to track the memory range
that has to be synchronized. For the kernel, we need to execute a
flush_tlb_kern_* immediately but we can wait for the first page fault in
case of set_ptes. For userspace in contrast we only store that a range
of memory needs to be synced and do so whenever we switch to that
process.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20240703134536.1161108-13-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03 17:09:50 +02:00
Benjamin Berg
573a446fc8 um: simplify and consolidate TLB updates
The HVC update was mostly used to compress consecutive calls into one.
This is mostly relevant for userspace where it is already handled by the
syscall stub code.

Simplify the whole logic and consolidate it for both kernel and
userspace. This does remove the sequential syscall compression for the
kernel, however that shouldn't be the main factor in most runs.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20240703134536.1161108-12-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03 17:09:50 +02:00
Benjamin Berg
3c83170d7c um: Delay flushing syscalls until the thread is restarted
As running the syscalls is expensive due to context switches, we should
do so as late as possible in case more syscalls need to be queued later
on. This will also benefit a later move to a SECCOMP enabled userspace
as in that case the need for extra context switches is removed entirely.

Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
Link: https://patch.msgid.link/20240703134536.1161108-9-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03 17:09:49 +02:00
Benjamin Berg
a5d2cfe749 um: remove copy_context_skas0
The kernel flushes the memory ranges anyway for CoW and does not assume
that the userspace process has anything set up already. So, start with a
fresh process for the new mm context.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20240703134536.1161108-8-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03 17:09:49 +02:00
Benjamin Berg
7911b650a0 um: remove LDT support
The current LDT code has a few issues that mean it should be redone in a
different way once we always start with a fresh MM even when cloning.

In a new and better world, the kernel would just ensure its own LDT is
clear at startup. At that point, all that is needed is a simple function
to populate the LDT from another MM in arch_dup_mmap combined with some
tracking of the installed LDT entries for each MM.

Note that the old implementation was even incorrect with regard to
reading, as it copied out the LDT entries in the internal format rather
than converting them to the userspace structure.

Removal should be fine as the LDT is not used for thread-local storage
anymore.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20240703134536.1161108-7-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03 17:09:49 +02:00
Benjamin Berg
76ed9158e1 um: Rework syscall handling
Rework syscall handling to be platform independent. Also create a clean
split between queueing of syscalls and flushing them out, removing the
need to keep state in the code that triggers the syscalls.

The code adds syscall_data_len to the global mm_id structure. This will
be used later to allow surrounding code to track whether syscalls still
need to run and if errors occurred.

Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
Link: https://patch.msgid.link/20240703134536.1161108-5-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03 17:09:49 +02:00
Benjamin Berg
dc26184a9d um: Create signal stack memory assignment in stub_data
When we switch to use seccomp, we need both the signal stack and other
data (i.e. syscall information) to co-exist in the stub data. To
facilitate this, start by defining separate memory areas for the stack
and syscall data.

This moves the signal stack onto a new page as the memory area is not
sufficient to hold both signal stack and syscall information.

Only change the signal stack setup for now, as the syscall code will be
reworked later.

Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
Link: https://patch.msgid.link/20240703134536.1161108-3-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03 17:09:48 +02:00
Benjamin Berg
d1d3a2e69b um: Remove stub-data.h include from common-offsets.h
Further commits will require values from common-offsets.h inside
stub-data.h. Resolve the possible circular dependency and simply use
offsetof() inside stub_32.h and stub_64.h.

Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
Link: https://patch.msgid.link/20240703134536.1161108-2-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03 17:09:48 +02:00
Johannes Berg
e20f9b3c59 um: add mmap/mremap OS calls
For the upcoming shared-memory time-travel external
optimisations, we need to be able to mmap/mremap.
Add the necessary OS calls.

Link: https://patch.msgid.link/20240702192118.ca4472963638.Ic2da1d3a983fe57340c1b693badfa9c5bd2d8c61@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03 12:24:48 +02:00
Johannes Berg
5cde6096a4 um: generalize os_rcv_fd
Change os_rcv_fd() to os_rcv_fd_msg() that can more generally
receive any number of FDs in any kind of message.

Link: https://patch.msgid.link/20240702192118.40b78b2bfe4e.Ic6ec12d72630e5bcae1e597d6bd5c6f29f441563@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03 12:24:25 +02:00
Mordechay Goodstein
6555acdefc um: time-travel: support time-travel protocol broadcast messages
Add a message type to the time-travel protocol to broadcast
a small (64-bit) value to all participants in a simulation.
The main use case is to have an identical message come to
all participants in a simulation, e.g. to separate out logs
for different tests running in a single simulation.

Down in the guts of time_travel_handle_message() we can't
use printk() and not even printk_deferred(), so just store
the message and print it at the start of the userspace()
function.

Unfortunately this means that other prints in the kernel
can actually bypass the message, but in most cases where
this is used, for example to separate test logs, userspace
will be involved. Also, even if we could use
printk_deferred(), we'd still need to flush it out in the
userspace() function since otherwise userspace messages
might cross it.

As a result, this is a reasonable compromise, there's no
need to have any core changes and it solves the main use
case we have for it.

Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Link: https://patch.msgid.link/20240702192118.c4093bc5b15e.I2ca8d006b67feeb866ac2017af7b741c9e06445a@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03 12:24:22 +02:00
Tiwei Bie
6fdae1da76 um: Remove unused ncpus variable
It's no longer used. And uml_ncpus_setup doesn't exist anymore.

Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20240527134024.1539848-2-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03 12:21:57 +02:00
Benjamin Berg
b2f9b77c7f um: chan: use blocking IO for console output for time-travel
When in time-travel mode (infinite-cpu or external) time should not pass
for writing to the console. As such, it makes sense to put the FD for
the output side into blocking mode and simply let any write to it hang.

If we did not do this, then time could pass waiting for the console to
become writable again. This is not desirable as it has random effects on
the clock between runs.

Implement this by duplicating the FD if output is active in a relevant
mode and setting the duplicate to be blocking. This avoids changing the
input channel to be blocking should it exists. After this, use the
blocking FD for all write operations and do not allocate an IRQ it is
set.

Without time-travel mode fd_out will always match fd_in and IRQs are
registered.

Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20231018123643.1255813-4-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2024-07-03 12:18:02 +02:00
Linus Torvalds
2313022ec5 Merge tag 'uml-for-linus-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux
Pull UML updates from Richard Weinberger:

 - Fixes for -Wmissing-prototypes warnings and further cleanup

 - Remove callback returning void from rtc and virtio drivers

 - Fix bash location

* tag 'uml-for-linus-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/uml/linux: (26 commits)
  um: virtio_uml: Convert to platform remove callback returning void
  um: rtc: Convert to platform remove callback returning void
  um: Remove unused do_get_thread_area function
  um: Fix -Wmissing-prototypes warnings for __vdso_*
  um: Add an internal header shared among the user code
  um: Fix the declaration of kasan_map_memory
  um: Fix the -Wmissing-prototypes warning for get_thread_reg
  um: Fix the -Wmissing-prototypes warning for __switch_mm
  um: Fix -Wmissing-prototypes warnings for (rt_)sigreturn
  um: Stop tracking host PID in cpu_tasks
  um: process: remove unused 'n' variable
  um: vector: remove unused len variable/calculation
  um: vector: fix bpfflash parameter evaluation
  um: slirp: remove set but unused variable 'pid'
  um: signal: move pid variable where needed
  um: Makefile: use bash from the environment
  um: Add winch to winch_handlers before registering winch IRQ
  um: Fix -Wmissing-prototypes warnings for __warp_* and foo
  um: Fix -Wmissing-prototypes warnings for text_poke*
  um: Move declarations to proper headers
  ...
2024-05-25 13:17:48 -07:00
Tiwei Bie
6a85e34c4d um: Fix the declaration of kasan_map_memory
Make it match its definition (size_t vs unsigned long). And declare
it in a shared header to fix the -Wmissing-prototypes warning, as it
is defined in the user code and called in the kernel code.

Fixes: 5b301409e8 ("UML: add support for KASAN under x86_64")
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2024-04-30 14:15:42 +02:00
Tiwei Bie
2cbade17b1 um: Fix the -Wmissing-prototypes warning for __switch_mm
The __switch_mm function is defined in the user code, and is called
by the kernel code. It should be declared in a shared header.

Fixes: 4dc706c2f2 ("um: take um_mmu.h to asm/mmu.h, clean asm/mmu_context.h a bit")
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2024-04-30 14:14:08 +02:00
Tiwei Bie
f95bab8610 um: Stop tracking host PID in cpu_tasks
The host PID tracked in 'cpu_tasks' is no longer used. Stopping
tracking it will also save some cycles.

Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2024-04-30 14:11:30 +02:00
Kent Overstreet
88ae5fb755 mm: vmalloc: enable memory allocation profiling
This wrapps all external vmalloc allocation functions with the
alloc_hooks() wrapper, and switches internal allocations to _noprof
variants where appropriate, for the new memory allocation profiling
feature.

[surenb@google.com: arch/um: fix forward declaration for vmalloc]
  Link: https://lkml.kernel.org/r/20240326073750.726636-1-surenb@google.com
[surenb@google.com: undo _noprof additions in the documentation]
  Link: https://lkml.kernel.org/r/20240326231453.1206227-5-surenb@google.com
Link: https://lkml.kernel.org/r/20240321163705.3067592-31-surenb@google.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Tested-by: Kees Cook <keescook@chromium.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alex Gaynor <alex.gaynor@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@samsung.com>
Cc: Benno Lossin <benno.lossin@proton.me>
Cc: "Björn Roy Baron" <bjorn3_gh@protonmail.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wedson Almeida Filho <wedsonaf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-04-25 20:55:57 -07:00
Tiwei Bie
a4b4382f3e um: Move declarations to proper headers
This will address below -Wmissing-prototypes warnings:

arch/um/kernel/initrd.c:18:12: warning: no previous prototype for ‘read_initrd’ [-Wmissing-prototypes]
arch/um/kernel/um_arch.c:408:19: warning: no previous prototype for ‘read_initrd’ [-Wmissing-prototypes]
arch/um/os-Linux/start_up.c:301:12: warning: no previous prototype for ‘parse_iomem’ [-Wmissing-prototypes]
arch/x86/um/ptrace_32.c:15:6: warning: no previous prototype for ‘arch_switch_to’ [-Wmissing-prototypes]
arch/x86/um/ptrace_32.c:101:5: warning: no previous prototype for ‘poke_user’ [-Wmissing-prototypes]
arch/x86/um/ptrace_32.c:153:5: warning: no previous prototype for ‘peek_user’ [-Wmissing-prototypes]
arch/x86/um/ptrace_64.c:111:5: warning: no previous prototype for ‘poke_user’ [-Wmissing-prototypes]
arch/x86/um/ptrace_64.c:171:5: warning: no previous prototype for ‘peek_user’ [-Wmissing-prototypes]
arch/x86/um/syscalls_64.c:48:6: warning: no previous prototype for ‘arch_switch_to’ [-Wmissing-prototypes]
arch/x86/um/tls_32.c:184:5: warning: no previous prototype for ‘arch_switch_tls’ [-Wmissing-prototypes]

Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2024-04-22 21:58:48 +02:00
Tiwei Bie
0c2b208c8b um: Fix the declaration of vfree
The definition of vfree has changed since commit b3bdda02aa
("vmalloc: add const to void* parameters"). Update the declaration
of vfree in um_malloc.h to match the latest definition.

Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2024-04-22 21:44:00 +02:00
Kees Cook
1e06589843 um: Convert strscpy() usage to 2-argument style
The ARCH=um build has its own idea about strscpy()'s definition. Adjust
the callers to remove the redundant sizeof() arguments ahead of treewide
changes, since it needs a manual adjustment for the newly named
sized_strscpy() export.

Cc: Richard Weinberger <richard@nod.at>
Cc: linux-um@lists.infradead.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-02-20 20:47:32 -08:00
Kees Cook
e6584c3964 string: Allow 2-argument strscpy()
Using sizeof(dst) for the "size" argument in strscpy() is the
overwhelmingly common case. Instead of requiring this everywhere, allow a
2-argument version to be used that will use the sizeof() internally. There
are other functions in the kernel with optional arguments[1], so this
isn't unprecedented, and improves readability. Update and relocate the
kern-doc for strscpy() too, and drop __HAVE_ARCH_STRSCPY as it is unused.

Adjust ARCH=um build to notice the changed export name, as it doesn't
do full header includes for the string helpers.

This could additionally let us save a few hundred lines of code:
 1177 files changed, 2455 insertions(+), 3026 deletions(-)
with a treewide cleanup using Coccinelle:

@needless_arg@
expression DST, SRC;
@@

        strscpy(DST, SRC
-, sizeof(DST)
        )

Link: https://elixir.bootlin.com/linux/v6.7/source/include/linux/pci.h#L1517 [1]
Reviewed-by: Justin Stitt <justinstitt@google.com>
Cc: Andy Shevchenko <andy@kernel.org>
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-02-20 20:47:32 -08:00
Benjamin Berg
1e41c415e2 um: Remove unused register save/restore functions
These functions were only used when calling PTRACE_ARCH_PRCTL, but this
code has been removed.

Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
Signed-off-by: Richard Weinberger <richard@nod.at>
2024-01-05 16:28:57 +01:00
Benjamin Berg
1ca1443570 um: Rely on PTRACE_SETREGSET to set FS/GS base registers
These registers are saved/restored together with the other general
registers using ptrace. In arch_set_tls we then just need to set the
register and it will be synced back normally.

Most of this logic was introduced in commit f355559cf7 ("[PATCH] uml:
x86_64 thread fixes"). However, at least today we can rely on ptrace to
restore the base registers for us. As such, only the part of the patch
that tracks the FS register for use as thread local storage is actually
needed.

Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
Signed-off-by: Richard Weinberger <richard@nod.at>
2024-01-05 16:28:56 +01:00
Benjamin Berg
a55719847d um: Drop support for hosts without SYSEMU_SINGLESTEP support
These features have existed since Linux 2.6.14 and can be considered
widely available at this point. Also drop the backward compatibility
code for PTRACE_SETOPTIONS.

Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>

----

v2:
 * Continue to define PTRACE_SYSEMU_SINGLESTEP as glibc only added it in
   version 2.27.
Signed-off-by: Richard Weinberger <richard@nod.at>
2024-01-04 23:29:11 +01:00
Anton Ivanov
541d4e4d43 um: Fix naming clash between UML and scheduler
__cant_sleep was already used and exported by the scheduler.
The name had to be changed to a UML specific one.

Signed-off-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Reviewed-by: Peter Lafreniere <peter@n8pjl.ca>
Signed-off-by: Richard Weinberger <richard@nod.at>
2024-01-04 21:22:27 +01:00
Nick Desaulniers
ab7ca2eb63 um: fix 3 instances of -Wmissing-prototypes
Fixes the following build errors observed from W=1 builds:
  arch/um/drivers/xterm_kern.c:35:5: warning: no previous prototype for
  function 'xterm_fd' [-Wmissing-prototypes]
  35 | int xterm_fd(int socket, int *pid_out)
     |     ^
  arch/um/drivers/xterm_kern.c:35:1: note: declare 'static' if the
  function is not intended to be used outside of this translation unit
  35 | int xterm_fd(int socket, int *pid_out)
     | ^
     | static
  arch/um/drivers/chan_kern.c:183:6: warning: no previous prototype for
  function 'free_irqs' [-Wmissing-prototypes]
  183 | void free_irqs(void)
      |      ^
  arch/um/drivers/chan_kern.c:183:1: note: declare 'static' if the
  function is not intended to be used outside of this translation unit
  183 | void free_irqs(void)
      | ^
      | static
  arch/um/drivers/slirp_kern.c:18:6: warning: no previous prototype for
  function 'slirp_init' [-Wmissing-prototypes]
  18 | void slirp_init(struct net_device *dev, void *data)
     |      ^
  arch/um/drivers/slirp_kern.c:18:1: note: declare 'static' if the
  function is not intended to be used outside of this translation unit
  18 | void slirp_init(struct net_device *dev, void *data)
     | ^
     | static

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202308081050.sZEw4cQ5-lkp@intel.com/
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2023-08-26 22:45:05 +02:00
Azeem Shaikh
f5ff432d96 um: Remove strlcpy usage
strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
[rw: Massaged subject]
Signed-off-by: Richard Weinberger <richard@nod.at>
2023-08-19 22:24:39 +02:00
Azeem Shaikh
f0a6b5831c uml: Replace strlcpy with strscpy
strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20230614003604.1021205-1-azeemshaikh38@gmail.com
2023-06-20 13:35:37 -07:00
Johannes Berg
6032aca0de um: make stub data pages size tweakable
There's a lot of code here that hard-codes that the
data is a single page, and right now that seems to
be sufficient, but to make it easier to change this
in the future, add a new STUB_DATA_PAGES constant
and use it throughout the code.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2023-04-20 23:08:43 +02:00
Linus Torvalds
79b7e67bb9 Merge tag 'for-linus-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml
Pull UML updates from Richard Weinberger:

 - KASAN support for x86_64

 - noreboot command line option, just like qemu's -no-reboot

 - Various fixes and cleanups

* tag 'for-linus-5.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: include sys/types.h for size_t
  um: Replace to_phys() and to_virt() with less generic function names
  um: Add missing apply_returns()
  um: add "noreboot" command line option for PANIC_TIMEOUT=-1 setups
  um: include linux/stddef.h for __always_inline
  UML: add support for KASAN under x86_64
  mm: Add PAGE_ALIGN_DOWN macro
  um: random: Don't initialise hwrng struct with zero
  um: remove unused mm_copy_segments
  um: remove unused variable
  um: Remove straying parenthesis
  um: x86: print RIP with symbol
  arch: um: Fix build for statically linked UML w/ constructors
  x86/um: Kconfig: Fix indentation
  um/drivers: Kconfig: Fix indentation
  um: Kconfig: Fix indentation
2022-08-05 14:03:11 -07:00
Jason A. Donenfeld
0b9ba6135d um: seed rng using host OS rng
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 <johannes@sipsolutions.net>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-07-18 15:04:04 +02:00
Jason A. Donenfeld
af3e16101c um: include sys/types.h for size_t
Usually size_t comes from sys/types.h, not stddef.h. This code likely
worked only because something else in its usage chain was pulling in
sys/types.h. stddef.h is still required for NULL, however, so note this.

Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2022-07-17 23:47:18 +02:00
Guenter Roeck
8970d5c9f4 um: Replace to_phys() and to_virt() with less generic function names
to_virt() and to_phys() are very generic and may be defined by drivers.
As it turns out, commit 9409c9b670 ("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: 9409c9b670 ("pmem: refactor pmem_clear_poison()")
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Acked-By: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2022-07-17 23:44:40 +02:00
Guenter Roeck
097da1a44d um: Replace to_phys() and to_virt() with less generic function names
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 9409c9b670 ("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: 9409c9b670 ("pmem: refactor pmem_clear_poison()")
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-07-14 11:57:27 -07:00
Linus Torvalds
e8b767f5e0 Merge tag 'for-linus-5.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml
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
2022-03-31 16:16:58 -07:00
Frédéric Danis
d2a0a616ab um: Fix WRITE_ZEROES in the UBD Driver
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 <frederic.danis@collabora.com>
Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2022-03-11 10:46:34 +01:00
Gustavo A. R. Silva
5224f79096 treewide: Replace zero-length arrays with flexible-array members
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 <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2022-02-17 07:00:39 -06:00
Al Viro
4c1f795773 um: header debriding - sigio.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-12-21 21:31:36 +01:00
Al Viro
021fdaef80 um: header debriding - os.h
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-12-21 21:31:36 +01:00
Al Viro
b31ef6d89d um: header debriding - net_*.h
externs dead since before the initial merge

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-12-21 21:31:35 +01:00
Al Viro
bb1a2c4e2d um: header debriding - mem_user.h
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 <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-12-21 21:31:35 +01:00
Al Viro
ed4b1cc590 um: header debriding - activate_ipi()
... had been dead for 15 years.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-12-21 21:31:35 +01:00
Al Viro
8e5d7cf347 um: common-offsets.h debriding...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-12-21 21:31:35 +01:00
Al Viro
2610ed63ea um, x86: bury crypto_tfm_ctx_offset
unused since 2011

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-12-21 21:31:35 +01:00
Al Viro
7f5f156dae um: remove a dangling extern of syscall_trace()
the function had been gone since 2012...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-12-21 21:31:35 +01:00
Al Viro
6605a44866 um: kill unused cpu()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-12-21 21:31:35 +01:00