David Daney 46011e6ea3 MIPS: Make set_pte() SMP safe. ...

On MIPS the GLOBAL bit of the PTE must have the same value in any
aligned pair of PTEs.  These pairs of PTEs are referred to as
"buddies".  In a SMP system is is possible for two CPUs to be calling
set_pte() on adjacent PTEs at the same time.  There is a race between
setting the PTE and a different CPU setting the GLOBAL bit in its
buddy PTE.

This race can be observed when multiple CPUs are executing
vmap()/vfree() at the same time.

Make setting the buddy PTE's GLOBAL bit an atomic operation to close
the race condition.

The case of CONFIG_64BIT_PHYS_ADDR && CONFIG_CPU_MIPS32 is *not*
handled.

Signed-off-by: David Daney <[email protected]>
Cc: <[email protected]>
Cc: [email protected]
Patchwork: https://patchwork.linux-mips.org/patch/10835/
Signed-off-by: Ralf Baechle <[email protected]>

2015-08-05 11:11:10 +02:00

..

asm

MIPS: Make set_pte() SMP safe.

2015-08-05 11:11:10 +02:00

uapi/asm

MIPS: asm-offset.c: Patch up various comments refering to the old filename.

2015-07-14 16:05:49 +02:00