linux-stable.git/arch/m68k, branch linux-4.9.y

m68k: use fallback for random_get_entropy() instead of zero

2022-06-25T09:45:13+00:00

commit 0f392c95391f2d708b12971a07edaa7973f9eece upstream.

In the event that random_get_entropy() can't access a cycle counter or
similar, falling back to returning 0 is really not the best we can do.
Instead, at least calling random_get_entropy_fallback() would be
preferable, because that always needs to return _something_, even
falling back to jiffies eventually. It's not as though
random_get_entropy_fallback() is super high precision or guaranteed to
be entropic, but basically anything that's not zero all the time is
better than returning zero all the time.

Cc: Thomas Gleixner 
Cc: Arnd Bergmann 
Acked-by: Geert Uytterhoeven 
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Greg Kroah-Hartman

m68knommu: fix undefined reference to `_init_sp'

2022-06-14T14:52:38+00:00

[ Upstream commit a71b9e66fee47c59b3ec34e652b5c23bc6550794 ]

When configuring a nommu classic m68k system enabling the uboot parameter
passing support (CONFIG_UBOOT) will produce the following compile error:

   m68k-linux-ld: arch/m68k/kernel/uboot.o: in function `process_uboot_commandline':
   uboot.c:(.init.text+0x32): undefined reference to `_init_sp'

The logic to support this option is only used on ColdFire based platforms
(in its head.S startup code). So make the selection of this option
depend on building for a ColdFire based platform.

Reported-by: kernel test robot 
Reviewed-by: Geert Uytterhoeven 
Acked-by: Geert Uytterhoeven 
Signed-off-by: Greg Ungerer 
Signed-off-by: Sasha Levin

m68knommu: set ZERO_PAGE() to the allocated zeroed page

2022-06-14T14:52:38+00:00

[ Upstream commit dc068f46217970d9516f16cd37972a01d50dc055 ]

The non-MMU m68k pagetable ZERO_PAGE() macro is being set to the
somewhat non-sensical value of "virt_to_page(0)". The zeroth page
is not in any way guaranteed to be a page full of "0". So the result
is that ZERO_PAGE() will almost certainly contain random values.

We already allocate a real "empty_zero_page" in the mm setup code shared
between MMU m68k and non-MMU m68k. It is just not hooked up to the
ZERO_PAGE() macro for the non-MMU m68k case.

Fix ZERO_PAGE() to use the allocated "empty_zero_page" pointer.

I am not aware of any specific issues caused by the old code.

Link: https://lore.kernel.org/linux-m68k/2a462b23-5b8e-bbf4-ec7d-778434a3b9d7@google.com/T/#t
Reported-by: Hugh Dickens 
Signed-off-by: Greg Ungerer 
Signed-off-by: Sasha Levin

m68k: math-emu: Fix dependencies of math emulation support

2022-06-14T14:52:32+00:00

[ Upstream commit ed6bc6bf0a7d75e80eb1df883c09975ebb74e590 ]

If CONFIG_M54xx=y, CONFIG_MMU=y, and CONFIG_M68KFPU_EMU=y:

    {standard input}:272: Error: invalid instruction for this architecture; needs 68000 or higher (68000 [68ec000, 68hc000, 68hc001, 68008, 68302, 68306, 68307, 68322, 68356], 68010, 68020 [68k, 68ec020], 68030 [68ec030], 68040 [68ec040], 68060 [68ec060], cpu32 [68330, 68331, 68332, 68333, 68334, 68336, 68340, 68341, 68349, 68360], fidoa [fido]) -- statement `sub.b %d1,%d3' ignored
    {standard input}:609: Error: invalid instruction for this architecture; needs 68020 or higher (68020 [68k, 68ec020], 68030 [68ec030], 68040 [68ec040], 68060 [68ec060]) -- statement `bfextu 4(%a1){%d0,#8},%d0' ignored
    {standard input}:752: Error: operands mismatch -- statement `mulu.l 4(%a0),%d3:%d0' ignored
    {standard input}:1155: Error: operands mismatch -- statement `divu.l %d0,%d3:%d7' ignored

The math emulation support code is intended for 68020 and higher, and
uses several instructions or instruction modes not available on coldfire
or 68000.

Originally, the dependency of M68KFPU_EMU on MMU was fine, as MMU
support was only available on 68020 or higher.  But this assumption
was broken by the introduction of MMU support for M547x and M548x.

Drop the dependency on MMU, as the code should work fine on 68020 and up
without MMU (which are not yet supported by Linux, though).
Add dependencies on M68KCLASSIC (to rule out Coldfire) and FPU (kernel
has some type of floating-point support --- be it hardware or software
emulated, to rule out anything below 68020).

Fixes: 1f7034b9616e6f14 ("m68k: allow ColdFire 547x and 548x CPUs to be built with MMU enabled")
Reported-by: kernel test robot 
Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Greg Ungerer 
Link: https://lore.kernel.org/r/18c34695b7c95107f60ccca82a4ff252f3edf477.1652446117.git.geert@linux-m68k.org
Signed-off-by: Sasha Levin

m68k: set a default value for MEMORY_RESERVE

2021-11-26T10:48:38+00:00

[ Upstream commit 1aaa557b2db95c9506ed0981bc34505c32d6b62b ]

'make randconfig' can produce a .config file with
"CONFIG_MEMORY_RESERVE=" (no value) since it has no default.
When a subsequent 'make all' is done, kconfig restarts the config
and prompts for a value for MEMORY_RESERVE. This breaks
scripting/automation where there is no interactive user input.

Add a default value for MEMORY_RESERVE. (Any integer value will
work here for kconfig.)

Fixes a kconfig warning:

.config:214:warning: symbol value '' invalid for MEMORY_RESERVE
* Restart config...
Memory reservation (MiB) (MEMORY_RESERVE) [] (NEW)

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") # from beginning of git history
Signed-off-by: Randy Dunlap 
Reviewed-by: Geert Uytterhoeven 
Cc: Greg Ungerer 
Cc: linux-m68k@lists.linux-m68k.org
Signed-off-by: Greg Ungerer 
Signed-off-by: Sasha Levin

m68k: Double cast io functions to unsigned long

2021-10-06T08:23:40+00:00

[ Upstream commit b1a89856fbf63fffde6a4771d8f1ac21df549e50 ]

m68k builds fail widely with errors such as

arch/m68k/include/asm/raw_io.h:20:19: error:
	cast to pointer from integer of different size
arch/m68k/include/asm/raw_io.h:30:32: error:
	cast to pointer from integer of different size [-Werror=int-to-p

On m68k, io functions are defined as macros. The problem is seen if the
macro parameter variable size differs from the size of a pointer. Cast
the parameter of all io macros to unsigned long before casting it to
a pointer to fix the problem.

Signed-off-by: Guenter Roeck 
Link: https://lore.kernel.org/r/20210907060729.2391992-1-linux@roeck-us.net
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Sasha Levin

m68k: emu: Fix invalid free in nfeth_cleanup()

2021-09-22T09:42:59+00:00

[ Upstream commit 761608f5cf70e8876c2f0e39ca54b516bdcb7c12 ]

In the for loop all nfeth_dev array members should be freed, not only
the first one.  Freeing only the first array member can cause
double-free bugs and memory leaks.

Fixes: 9cd7b148312f ("m68k/atari: ARAnyM - Add support for network access")
Signed-off-by: Pavel Skripkin 
Link: https://lore.kernel.org/r/20210705204727.10743-1-paskripkin@gmail.com
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Sasha Levin

m68k: q40: Fix info-leak in rtc_ioctl

2020-10-01T18:40:01+00:00

[ Upstream commit 7cf78b6b12fd5550545e4b73b35dca18bd46b44c ]

When the option is RTC_PLL_GET, pll will be copied to userland
via copy_to_user. pll is initialized using mach_get_rtc_pll indirect
call and mach_get_rtc_pll is only assigned with function
q40_get_rtc_pll in arch/m68k/q40/config.c.
In function q40_get_rtc_pll, the field pll_ctrl is not initialized.
This will leak uninitialized stack content to userland.
Fix this by zeroing the uninitialized field.

Signed-off-by: Fuqian Huang 
Link: https://lore.kernel.org/r/20190927121544.7650-1-huangfq.daxian@gmail.com
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Sasha Levin

m68knommu: fix overwriting of bits in ColdFire V3 cache control

2020-08-26T08:29:04+00:00

[ Upstream commit bdee0e793cea10c516ff48bf3ebb4ef1820a116b ]

The Cache Control Register (CACR) of the ColdFire V3 has bits that
control high level caching functions, and also enable/disable the use
of the alternate stack pointer register (the EUSP bit) to provide
separate supervisor and user stack pointer registers. The code as
it is today will blindly clear the EUSP bit on cache actions like
invalidation. So it is broken for this case - and that will result
in failed booting (interrupt entry and exit processing will be
completely hosed).

This only affects ColdFire V3 parts that support the alternate stack
register (like the 5329 for example) - generally speaking new parts do,
older parts don't. It has no impact on ColdFire V3 parts with the single
stack pointer, like the 5307 for example.

Fix the cache bit defines used, so they maintain the EUSP bit when
carrying out cache actions through the CACR register.

Signed-off-by: Greg Ungerer 
Signed-off-by: Sasha Levin

m68k: mac: Fix IOP status/control register writes

2020-08-21T09:01:57+00:00

[ Upstream commit 931fc82a6aaf4e2e4a5490addaa6a090d78c24a7 ]

When writing values to the IOP status/control register make sure those
values do not have any extraneous bits that will clear interrupt flags.

To place the SCC IOP into bypass mode would be desirable but this is not
achieved by writing IOP_DMAINACTIVE | IOP_RUN | IOP_AUTOINC | IOP_BYPASS
to the control register. Drop this ineffective register write.

Remove the flawed and unused iop_bypass() function. Make use of the
unused iop_stop() function.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Finn Thain 
Tested-by: Stan Johnson 
Cc: Joshua Thompson 
Link: https://lore.kernel.org/r/09bcb7359a1719a18b551ee515da3c4c3cf709e6.1590880333.git.fthain@telegraphics.com.au
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Sasha Levin