This selects the THREAD_INFO_IN_TASK option for UM and changes the way
that the current task is discovered. This is trivial though, as UML
already tracks the current task in cpu_tasks[] and this can be used to
retrieve it.
Also remove the signal handler code that copies the thread information
into the IRQ stack. It is obsolete now, which also means that the
mentioned race condition cannot happen anymore.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Reviewed-by: Hajime Tazaki <thehajime@gmail.com>
Link: https://patch.msgid.link/20241111102910.46512-1-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The show_stack function had some code to detect double faults. However,
the logic is wrong and it would e.g. trigger if a WARNING happened
inside an IRQ.
Remove it without trying to add a new logic. The current behaviour,
which will just fault repeatedly until the IRQ stack is used up and the
host kills UML, seems to be good enough.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20241103150506.1367695-5-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
There is no need to sync the stub code to "disk" for the other process
to see the correct memory. Drop the fsync there and remove the helper
function.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20241103150506.1367695-3-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Since commit a95b37e20d ("kbuild: get <linux/compiler_types.h> out of
<linux/kconfig.h>") we can safely include these files in userspace code.
Doing so simplifies matters as options do not need to be exported via
asm-offsets.h anymore.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20241103150506.1367695-2-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This helper can be used to set the parent-death signal of the calling
process to SIGKILL to ensure that the process will be killed if the
UML kernel dies unexpectedly without proper cleanup. This helper will
be used in the follow-up patches.
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20241024142828.2612828-2-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
In time-travel mode userspace can do a lot of work without any time
passing. Unfortunately, this can result in OOM situations as the RCU
core code will never be run.
Work around this by keeping track of userspace processes that do not
yield for a lot of operations. When this happens, insert a jiffie into
the sched_clock clock to account time against the process and cause the
bookkeeping to run.
As sched_clock is used for tracing, it is useful to keep it in sync
between the different VMs. As such, try to remove added ticks again when
the actual clock ticks.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20241010142537.1134685-1-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When a PTE is updated in the page table, the _PAGE_NEWPAGE bit will
always be set. And the corresponding page will always be mapped or
unmapped depending on whether the PTE is present or not. The check
on the _PAGE_NEWPROT bit is not really reachable. Abandoning it will
allow us to simplify the code and remove the unreachable code.
Reviewed-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20241011102354.1682626-2-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This was perhaps intended to do _nofault copies, but the
real reason is lost to history. Remove this, it's not
needed, and using longjmp() out of the middle of the
signal handler with all the state it has modified is
not going to be a good idea anyway.
Link: https://patch.msgid.link/20241010224513.901c4d390b3e.Ia74742668b44603c1ca23dd36f90e964e6e7ee55@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When loading the UML binary, the host kernel will place the stack at the
highest possible address. It will then map the program name and
environment variables onto the start of the stack.
As such, an easy way to figure out the host_task_size is to use the
highest pointer to an environment variable as a reference.
Ensure that this works by disabling address layout randomization and
re-executing UML in case it was enabled.
This increases the available TASK_SIZE for 64 bit UML considerably.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20240919124511.282088-9-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Using clone will not undo features that have been enabled by libc. An
example of this already happening is rseq, which could cause the kernel
to read/write memory of the userspace process. In the future the
standard library might also use mseal by default to protect itself,
which would also thwart our attempts at unmapping everything.
Solve all this by taking a step back and doing an execve into a tiny
static binary that sets up the minimal environment required for the
stub without using any standard library. That way we have a clean
execution environment that is fully under the control of UML.
Note that this changes things a bit as the FDs are not anymore shared
with the kernel. Instead, we explicitly share the FDs for the physical
memory and all existing iomem regions. Doing this is fine, as iomem
regions cannot be added at runtime.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20240919124511.282088-3-benjamin@sipsolutions.net
[use pipe() instead of pipe2(), remove unneeded close() calls]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
We do not need the extra save/restore of the FP registers when getting
the fault information. This was originally added in commit 2f56debd77
("uml: fix FP register corruption") but at that time the code was not
saving/restoring the FP registers when switching to userspace. This was
fixed in commit fbfe9c847e ("um: Save FPU registers between task
switches") and since then the auxiliary registers have not been useful.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20241004233821.2130874-1-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When switching from userspace to the kernel, all registers including the
FP registers are copied into the kernel and restored later on. As such,
the true source for the FP register state is actually already in the
kernel and they should never be grabbed from the userspace process.
Change the various places to simply copy the data from the internal FP
register storage area. Note that on i386 the format of PTRACE_GETFPREGS
and PTRACE_GETFPXREGS is different enough that conversion would be
needed. With this patch, -EINVAL is returned if the non-native format is
requested.
The upside is, that this patchset fixes setting registers via ptrace
(which simply did not work before) as well as fixing setting floating
point registers using the mcontext on signal return on i386.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Link: https://patch.msgid.link/20240913133845.964292-1-benjamin@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Currently physmem_size is defined as long long but declared locally
as unsigned long long before using it in separate .c files. Make them
match by defining physmem_size as unsigned long long and also move
the declaration to a common header to allow the compiler to check it.
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20240916045950.508910-5-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Highmem was only supported on UML/i386. And the support has been
removed by commit a98a6d864d ("um: Remove broken highmem support").
Remove the leftovers and stop UML from trying to setup highmem when
the sum of physmem_size and iomem_size exceeds max_physmem.
Signed-off-by: Tiwei Bie <tiwei.btw@antgroup.com>
Link: https://patch.msgid.link/20240916045950.508910-4-tiwei.btw@antgroup.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
- Fixes for -Wmissing-prototypes warnings and further cleanup
- Remove callback returning void from rtc and virtio drivers
- Fix bash location
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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
...
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
__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>
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>
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>
