• David S. Miller's avatar
    sparc64: Fix sun4u execute bit check in TSB I-TLB load. · 1f474646
    David S. Miller authored
    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>
    1f474646
tsb.S 12.1 KB