sparc64: fix fault handling in NGbzero.S and GENbzero.S
authorDave Aldridge <david.j.aldridge@oracle.com>
Tue, 9 May 2017 08:57:35 +0000 (02:57 -0600)
committerDavid S. Miller <davem@davemloft.net>
Tue, 9 May 2017 19:16:25 +0000 (12:16 -0700)
commit3c7f62212018b904ae17f5636ead18a4dca3a88f
tree3563b65cdb09b8257fcd890dbab0db14213c97d1
parentaed74ea0a09d2e60e4b3fe45caf30f6365b6c9f3
sparc64: fix fault handling in NGbzero.S and GENbzero.S

When any of the functions contained in NGbzero.S and GENbzero.S
vector through *bzero_from_clear_user, we may end up taking a
fault when executing one of the store alternate address space
instructions. If this happens, the exception handler does not
restore the %asi register.

This commit fixes the issue by introducing a new exception
handler that ensures the %asi register is restored when
a fault is handled.

Orabug: 25577560

Signed-off-by: Dave Aldridge <david.j.aldridge@oracle.com>
Reviewed-by: Rob Gardner <rob.gardner@oracle.com>
Reviewed-by: Babu Moger <babu.moger@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
arch/sparc/kernel/head_64.S
arch/sparc/lib/GENbzero.S
arch/sparc/lib/NGbzero.S