libc/x86: ensure the stack 16-byte aligned when tasks created
Currently Renderscript sample code RsBalls crashed on x86 when SSE2
enabled. The root cause is that the stack was not 16-byte aligned
from the beginning when the processes/threads were created, so the
RsBalls crashed when SSE2 instructions tried to access the variables
on the stack.
- For the thread created by fork():
Its stack alignment is determined by crtbegin_{dynamic, static}.S
- For the thread created by pthread_create():
Its stack alignment is determined by clone.S. __thread_entry( ) is
a standard C function. In order to have its stack be aligned with
16 byte properly, __thread_entry() needs the stack with following
layout when it is called:
layout #1 (correct)
--------------
| |
-------------- <--ESP (ECX - 20)
| ret EIP |
-------------- <--ECX - 16
| arg0 |
-------------- <--ECX - 12
| arg1 |
-------------- <--ECX - 8
| arg2 |
-------------- <--ECX - 4
| unused |
-------------- <--ECX (16-byte boundary)
But it has following layout for now:
layout #2: (incorrect)
--------------
| |
-------------- <--ESP (ECX - 16)
| unused |
-------------- <--ECX - 12
| arg0 |
-------------- <--ECX - 8
| arg1 |
-------------- <--ECX - 4
| arg2 |
-------------- <--ECX (16-byte boundary)
Fixed in this patch.
Change-Id: Ibe01f64db14be14033c505d854c73033556ddaa8
Signed-off-by: Michael Liao <michael.liao@intel.com>
Signed-off-by: H.J. Lu <hongjiu.lu@intel.com>
Signed-off-by: Jack Ren <jack.ren@intel.com>
Signed-off-by: Bruce Beare <bruce.j.beare@intel.com>
3 files changed
