Commit 1f474646 authored by David S. Miller's avatar David S. Miller

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: default avatarDavid S. Miller <davem@davemloft.net>
parent d7ecfb3c
......@@ -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
......
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