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authorDavid S. Miller <davem@davemloft.net>2010-02-19 18:19:52 -0500
committerDavid S. Miller <davem@davemloft.net>2010-02-19 18:19:52 -0500
commit1f474646fdc36b457606bbcd6a3592e6cbd31ac4 (patch)
tree706149d39c9de0bc0ceacfb2ab44e909caba5b3c /arch
parentd7ecfb3c2aa155c9f6152ebe91de92067d16ba6e (diff)
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/sparc/kernel/tsb.S6
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:
191 191
192tsb_itlb_load: 192tsb_itlb_load:
193 /* Executable bit must be set. */ 193 /* Executable bit must be set. */
194661: andcc %g5, _PAGE_EXEC_4U, %g0 194661: sethi %hi(_PAGE_EXEC_4U), %g4
195 .section .sun4v_1insn_patch, "ax" 195 andcc %g5, %g4, %g0
196 .section .sun4v_2insn_patch, "ax"
196 .word 661b 197 .word 661b
197 andcc %g5, _PAGE_EXEC_4V, %g0 198 andcc %g5, _PAGE_EXEC_4V, %g0
199 nop
198 .previous 200 .previous
199 201
200 be,pn %xcc, tsb_do_fault 202 be,pn %xcc, tsb_do_fault