linux.git/arch/alpha/include, branch v5.15.197

sched: Add wrapper for get_wchan() to keep task blocked

2025-08-28T14:24:03+00:00

commit 42a20f86dc19f9282d974df0ba4d226c865ab9dd upstream.

Having a stable wchan means the process must be blocked and for it to
stay that way while performing stack unwinding.

Suggested-by: Peter Zijlstra 
Signed-off-by: Kees Cook 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Geert Uytterhoeven 
Acked-by: Russell King (Oracle)  [arm]
Tested-by: Mark Rutland  [arm64]
Link: https://lkml.kernel.org/r/20211008111626.332092234@infradead.org
Signed-off-by: Siddhi Katage 
Signed-off-by: Greg Kroah-Hartman

alpha/elf: Fix misc/setarch test of util-linux by removing 32bit support

2025-04-10T12:31:50+00:00

[ Upstream commit b029628be267cba3c7684ec684749fe3e4372398 ]

Richard Henderson  writes[1]:

> There was a Spec benchmark (I forget which) which was memory bound and ran
> twice as fast with 32-bit pointers.
>
> I copied the idea from DEC to the ELF abi, but never did all the other work
> to allow the toolchain to take advantage.
>
> Amusingly, a later Spec changed the benchmark data sets to not fit into a
> 32-bit address space, specifically because of this.
>
> I expect one could delete the ELF bit and personality and no one would
> notice. Not even the 10 remaining Alpha users.

In [2] it was pointed out that parts of setarch weren't working
properly on alpha because it has it's own SET_PERSONALITY
implementation.  In the discussion that followed Richard Henderson
pointed out that the 32bit pointer support for alpha was never
completed.

Fix this by removing alpha's 32bit pointer support.

As a bit of paranoia refuse to execute any alpha binaries that have
the EF_ALPHA_32BIT flag set.  Just in case someone somewhere has
binaries that try to use alpha's 32bit pointer support.

Link: https://lkml.kernel.org/r/CAFXwXrkgu=4Qn-v1PjnOR4SG0oUb9LSa0g6QXpBq4ttm52pJOQ@mail.gmail.com [1]
Link: https://lkml.kernel.org/r/20250103140148.370368-1-glaubitz@physik.fu-berlin.de [2]
Signed-off-by: Eric W. Biederman 
Reviewed-by: Richard Henderson 
Reviewed-by: Arnd Bergmann 
Reviewed-by: John Paul Adrian Glaubitz 
Tested-by: John Paul Adrian Glaubitz 
Link: https://lore.kernel.org/r/87y0zfs26i.fsf_-_@email.froward.int.ebiederm.org
Signed-off-by: Kees Cook 
Signed-off-by: Sasha Levin

alpha: make stack 16-byte aligned (most cases)

2025-03-13T11:50:40+00:00

commit 0a0f7362b0367634a2d5cb7c96226afc116f19c9 upstream.

The problem is that GCC expects 16-byte alignment of the incoming stack
since early 2004, as Maciej found out [1]:
  Having actually dug speculatively I can see that the psABI was changed in
 GCC 3.5 with commit e5e10fb4a350 ("re PR target/14539 (128-bit long double
 improperly aligned)") back in Mar 2004, when the stack pointer alignment
 was increased from 8 bytes to 16 bytes, and arch/alpha/kernel/entry.S has
 various suspicious stack pointer adjustments, starting with SP_OFF which
 is not a whole multiple of 16.

Also, as Magnus noted, "ALPHA Calling Standard" [2] required the same:
 D.3.1 Stack Alignment
  This standard requires that stacks be octaword aligned at the time a
  new procedure is invoked.

However:
- the "normal" kernel stack is always misaligned by 8 bytes, thanks to
  the odd number of 64-bit words in 'struct pt_regs', which is the very
  first thing pushed onto the kernel thread stack;
- syscall, fault, interrupt etc. handlers may, or may not, receive aligned
  stack depending on numerous factors.

Somehow we got away with it until recently, when we ended up with
a stack corruption in kernel/smp.c:smp_call_function_single() due to
its use of 32-byte aligned local data and the compiler doing clever
things allocating it on the stack.

This adds padding between the PAL-saved and kernel-saved registers
so that 'struct pt_regs' have an even number of 64-bit words.
This makes the stack properly aligned for most of the kernel
code, except two handlers which need special threatment.

Note: struct pt_regs doesn't belong in uapi/asm; this should be fixed,
but let's put this off until later.

Link: https://lore.kernel.org/rcu/alpine.DEB.2.21.2501130248010.18889@angie.orcam.me.uk/ [1]
Link: https://bitsavers.org/pdf/dec/alpha/Alpha_Calling_Standard_Rev_2.0_19900427.pdf [2]

Cc: stable@vger.kernel.org
Tested-by: Maciej W. Rozycki 
Tested-by: Magnus Lindholm 
Tested-by: Matt Turner 
Reviewed-by: Maciej W. Rozycki 
Signed-off-by: Ivan Kokshaysky 
Signed-off-by: Matt Turner 
Signed-off-by: Greg Kroah-Hartman

init: Remove check_bugs() leftovers

2023-08-08T17:58:31+00:00

commit 61235b24b9cb37c13fcad5b9596d59a1afdcec30 upstream

Everything is converted over to arch_cpu_finalize_init(). Remove the
check_bugs() leftovers including the empty stubs in asm-generic, alpha,
parisc, powerpc and xtensa.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Richard Henderson 
Link: https://lore.kernel.org/r/20230613224545.553215951@linutronix.de
Signed-off-by: Daniel Sneddon 
Signed-off-by: Greg Kroah-Hartman

alpha: fix TIF_NOTIFY_SIGNAL handling

2022-12-31T12:14:01+00:00

[ Upstream commit e2c7554cc6d85f95e3c6635f270ec839ab9fe05e ]

it needs to be added to _TIF_WORK_MASK, or we might not reach
do_work_pending() in the first place...

Fixes: 5a9a8897c253a "alpha: add support for TIF_NOTIFY_SIGNAL"
Signed-off-by: Al Viro 
Signed-off-by: Sasha Levin

alpha: fix alloc_zeroed_user_highpage_movable()

2022-06-09T08:22:43+00:00

[ Upstream commit f9c668d281aa20e38c9bda3b7b0adeb8891aa15e ]

Due to a typo, the final argument to alloc_page_vma() didn't refer to a
real variable.  This only affected CONFIG_NUMA, which was marked BROKEN in
2006 and removed from alpha in 2021.  Found due to a refactoring patch.

Link: https://lkml.kernel.org/r/20220504182857.4013401-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) 
Reported-by: kernel test robot 
Reviewed-by: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Sasha Levin

alpha: define get_cycles macro for arch-override

2022-05-30T07:29:13+00:00

commit 1097710bc9660e1e588cf2186a35db3d95c4d258 upstream.

Alpha defines a get_cycles() function, but it does not do the usual
`#define get_cycles get_cycles` dance, making it impossible for generic
code to see if an arch-specific function was defined. While the
get_cycles() ifdef is not currently used, the following timekeeping
patch in this series will depend on the macro existing (or not existing)
when defining random_get_entropy().

Cc: Thomas Gleixner 
Cc: Arnd Bergmann 
Cc: Richard Henderson 
Cc: Ivan Kokshaysky 
Acked-by: Matt Turner 
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

alpha: move __udiv_qrnnd library function to arch/alpha/lib/

2021-09-18T21:45:48+00:00

We already had the implementation for __udiv_qrnnd (unsigned divide for
multi-precision arithmetic) as part of the alpha math emulation code.

But you can disable the math emulation code - even if you shouldn't -
and then the MPI code that actually wants this functionality (and is
needed by various crypto functions) will fail to build.

So move the extended-precision divide code to be a regular library
function, just like all the regular division code is.  That way ie is
available regardless of math-emulation.

Signed-off-by: Linus Torvalds

alpha: make 'Jensen' IO functions build again

2021-09-18T17:57:10+00:00

The Jensen IO functions are overly copmplicated because some of the IO
addresses refer to special 'local IO' ports, and they get accessed
differently.

That then makes gcc not actually inline them, and since they were marked
"extern inline" when included through the regular  path, and
then only marked "inline" when included from sys_jensen.c, you never
necessarily got a body for the IO functions at all.

The intent of the sys_jensen.c code is to actually get the non-inlined
copy generated, so remove the 'inline' from the magic macro that is
supposed to sort this all out.

Also, do not mix 'extern inline' functions (that may or may not be
inlined and will not generate a function body if they are not) with
'static inline' (that _will_ generate a function body when not inlined).
Because gcc will complain about this situation:

   error: ‘jensen_bus_outb’ is static but used in inline function ‘jensen_outb’ which is not static

because gcc basically doesn't know whether to generate a body for that
static inline function or not for that call site.

So make all of these use that __EXTERN_INLINE marker.  Gcc will
generally not inline these things on use, and then generate the function
body out-of-line in sys_jensen.c.

This makes the core IO functions build for the alpha Jensen config.

Not that the rest then builds, because it turns out Jensen also doesn't
enable PCI, which then makes other drievrs very unhappy, but that's a
separate issue.

Signed-off-by: Linus Torvalds

alpha: Declare virt_to_phys and virt_to_bus parameter as pointer to volatile

2021-09-16T18:27:32+00:00

Some drivers pass a pointer to volatile data to virt_to_bus() and
virt_to_phys(), and that works fine.  One exception is alpha.  This
results in a number of compile errors such as

  drivers/net/wan/lmc/lmc_main.c: In function 'lmc_softreset':
  drivers/net/wan/lmc/lmc_main.c:1782:50: error:
	passing argument 1 of 'virt_to_bus' discards 'volatile'
	qualifier from pointer target type

  drivers/atm/ambassador.c: In function 'do_loader_command':
  drivers/atm/ambassador.c:1747:58: error:
	passing argument 1 of 'virt_to_bus' discards 'volatile'
	qualifier from pointer target type

Declare the parameter of virt_to_phys and virt_to_bus as pointer to
volatile to fix the problem.

Signed-off-by: Guenter Roeck 
Acked-by: Arnd Bergmann 
Signed-off-by: Linus Torvalds