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| author | David S. Miller <davem@davemloft.net> | 2010-02-20 02:19:52 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-02-20 02:19:52 +0300 |
| commit | 1f474646fdc36b457606bbcd6a3592e6cbd31ac4 (patch) | |
| tree | 706149d39c9de0bc0ceacfb2ab44e909caba5b3c | |
| parent | d7ecfb3c2aa155c9f6152ebe91de92067d16ba6e (diff) | |
| download | linux-1f474646fdc36b457606bbcd6a3592e6cbd31ac4.tar.xz | |
sparc64: Fix sun4u execute bit check in TSB I-TLB load.
Thanks to testcase and report from Brad Spengler:
--------------------
#include <stdio.h>
typedef int (* _wee)(void);
int main(void)
{
char buf[8] = { '\x81', '\xc7', '\xe0', '\x08', '\x81', '\xe8',
'\x00', '\x00' };
_wee wee;
printf("%p\n", &buf);
wee = (_wee)&buf;
wee();
return 0;
}
--------------------
TSB I-tlb load code tries to use andcc to check the _PAGE_EXEC_4U bit,
but that's bit 12 so it gets sign extended all the way up to bit 63
and the test nearly always passes as a result.
Use sethi to fix the bug.
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | arch/sparc/kernel/tsb.S | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/sparc/kernel/tsb.S b/arch/sparc/kernel/tsb.S index 8c91d9b29a2f..db15d123f054 100644 --- a/arch/sparc/kernel/tsb.S +++ b/arch/sparc/kernel/tsb.S @@ -191,10 +191,12 @@ tsb_dtlb_load: tsb_itlb_load: /* Executable bit must be set. */ -661: andcc %g5, _PAGE_EXEC_4U, %g0 - .section .sun4v_1insn_patch, "ax" +661: sethi %hi(_PAGE_EXEC_4U), %g4 + andcc %g5, %g4, %g0 + .section .sun4v_2insn_patch, "ax" .word 661b andcc %g5, _PAGE_EXEC_4V, %g0 + nop .previous be,pn %xcc, tsb_do_fault |