linux.git/arch/nios2/kernel, branch v6.6

nios2: Replace all non-returning strlcpy with strscpy

2023-06-13T21:51:49+00:00

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

Reviewed-by: Kees Cook 
Signed-off-by: Azeem Shaikh 
Signed-off-by: Dinh Nguyen

arch/idle: Change arch_cpu_idle() behavior: always exit with IRQs disabled

2023-01-13T10:48:15+00:00

Current arch_cpu_idle() is called with IRQs disabled, but will return
with IRQs enabled.

However, the very first thing the generic code does after calling
arch_cpu_idle() is raw_local_irq_disable(). This means that
architectures that can idle with IRQs disabled end up doing a
pointless 'enable-disable' dance.

Therefore, push this IRQ disabling into the idle function, meaning
that those architectures can avoid the pointless IRQ state flipping.

Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Ingo Molnar 
Tested-by: Tony Lindgren 
Tested-by: Ulf Hansson 
Reviewed-by: Gautham R. Shenoy 
Acked-by: Mark Rutland  [arm64]
Acked-by: Rafael J. Wysocki 
Acked-by: Guo Ren 
Acked-by: Frederic Weisbecker 
Link: https://lore.kernel.org/r/20230112195540.618076436@infradead.org

objtool/idle: Validate __cpuidle code as noinstr

2023-01-13T10:48:15+00:00

Idle code is very like entry code in that RCU isn't available. As
such, add a little validation.

Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Ingo Molnar 
Tested-by: Tony Lindgren 
Tested-by: Ulf Hansson 
Acked-by: Geert Uytterhoeven 
Acked-by: Rafael J. Wysocki 
Acked-by: Frederic Weisbecker 
Link: https://lore.kernel.org/r/20230112195540.373461409@infradead.org

nios2: ptrace: user_regset_copyin_ignore() always returns 0

2022-11-15T22:30:40+00:00

user_regset_copyin_ignore() always returns 0, so checking its result seems
pointless -- don't do this anymore...

Link: https://lkml.kernel.org/r/20221014212235.10770-8-s.shtylyov@omp.ru
Signed-off-by: Sergey Shtylyov 
Cc: Brian Cain 
Cc: Catalin Marinas 
Cc: Christophe Leroy 
Cc: David S. Miller 
Cc: Dinh Nguyen 
Cc: Helge Deller 
Cc: James Bottomley 
Cc: Jonas Bonn 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Oleg Nesterov 
Cc: Rich Felker 
Cc: Russell King 
Cc: Stafford Horne 
Cc: Stefan Kristiansson 
Cc: Thomas Bogendoerfer 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Signed-off-by: Andrew Morton

kbuild: use obj-y instead extra-y for objects placed at the head

2022-10-02T09:04:05+00:00

The objects placed at the head of vmlinux need special treatments:

 - arch/$(SRCARCH)/Makefile adds them to head-y in order to place
   them before other archives in the linker command line.

 - arch/$(SRCARCH)/kernel/Makefile adds them to extra-y instead of
   obj-y to avoid them going into built-in.a.

This commit gets rid of the latter.

Create vmlinux.a to collect all the objects that are unconditionally
linked to vmlinux. The objects listed in head-y are moved to the head
of vmlinux.a by using 'ar m'.

With this, arch/$(SRCARCH)/kernel/Makefile can consistently use obj-y
for builtin objects.

There is no *.o that is directly linked to vmlinux. Drop unneeded code
in scripts/clang-tools/gen_compile_commands.py.

$(AR) mPi needs 'T' to workaround the llvm-ar bug. The fix was suggested
by Nathan Chancellor [1].

[1]: https://lore.kernel.org/llvm/YyjjT5gQ2hGMH0ni@dev-arch.thelio-3990X/

Signed-off-by: Masahiro Yamada 
Tested-by: Nick Desaulniers 
Reviewed-by: Nicolas Schier

nios2: add force_successful_syscall_return()

2022-08-15T16:25:32+00:00

If we use the ancient SysV syscall ABI, we'd better have tell the
kernel how to claim that a negative return value is a success.
Use ->orig_r2 for that - it's inaccessible via ptrace, so it's
a fair game for changes and it's normally[*] non-negative on return
from syscall.  Set to -1; syscall is not going to be restart-worthy
by definition, so we won't interfere with that use either.

[*] the only exception is rt_sigreturn(), where we skip the entire
messing with r1/r2 anyway.

Fixes: 82ed08dd1b0e ("nios2: Exception handling")
Signed-off-by: Al Viro 
Signed-off-by: Dinh Nguyen

nios2: restarts apply only to the first sigframe we build...

2022-08-15T16:25:32+00:00

Fixes: b53e906d255d ("nios2: Signal handling support")
Signed-off-by: Al Viro 
Signed-off-by: Dinh Nguyen

nios2: fix syscall restart checks

2022-08-15T16:25:32+00:00

sys_foo() returns -512 (aka -ERESTARTSYS) => do_signal() sees
512 in r2 and 1 in r1.

sys_foo() returns 512 => do_signal() sees 512 in r2 and 0 in r1.

The former is restart-worthy; the latter obviously isn't.

Fixes: b53e906d255d ("nios2: Signal handling support")
Signed-off-by: Al Viro 
Signed-off-by: Dinh Nguyen

nios2: traced syscall does need to check the syscall number

2022-08-15T16:25:32+00:00

all checks done before letting the tracer modify the register
state are worthless...

Fixes: 82ed08dd1b0e ("nios2: Exception handling")
Signed-off-by: Al Viro 
Signed-off-by: Dinh Nguyen

nios2: don't leave NULLs in sys_call_table[]

2022-08-15T16:25:32+00:00

fill the gaps in there with sys_ni_syscall, as everyone does...

Fixes: 82ed08dd1b0e ("nios2: Exception handling")
Signed-off-by: Al Viro 
Signed-off-by: Dinh Nguyen