m68k: Fix assembler constraint to prevent overeager gcc optimisation
Passing the address of a variable as an operand to an asm statement
doesn't mark the value of this variable as used, so gcc may optimize its
initialisation away. Fix this by using the "m" constraint instead.
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org
diff --git a/arch/m68k/kernel/traps.c b/arch/m68k/kernel/traps.c
index 89362f2..eb67469 100644
--- a/arch/m68k/kernel/traps.c
+++ b/arch/m68k/kernel/traps.c
@@ -552,13 +552,13 @@
#ifdef DEBUG
asm volatile ("ptestr %3,%2@,#7,%0\n\t"
- "pmove %%psr,%1@"
- : "=a&" (desc)
- : "a" (&temp), "a" (addr), "d" (ssw));
+ "pmove %%psr,%1"
+ : "=a&" (desc), "=m" (temp)
+ : "a" (addr), "d" (ssw));
#else
asm volatile ("ptestr %2,%1@,#7\n\t"
- "pmove %%psr,%0@"
- : : "a" (&temp), "a" (addr), "d" (ssw));
+ "pmove %%psr,%0"
+ : "=m" (temp) : "a" (addr), "d" (ssw));
#endif
mmusr = temp;
@@ -605,20 +605,18 @@
!(ssw & RW) ? "write" : "read", addr,
fp->ptregs.pc, ssw);
asm volatile ("ptestr #1,%1@,#0\n\t"
- "pmove %%psr,%0@"
- : /* no outputs */
- : "a" (&temp), "a" (addr));
+ "pmove %%psr,%0"
+ : "=m" (temp)
+ : "a" (addr));
mmusr = temp;
printk ("level 0 mmusr is %#x\n", mmusr);
#if 0
- asm volatile ("pmove %%tt0,%0@"
- : /* no outputs */
- : "a" (&tlong));
+ asm volatile ("pmove %%tt0,%0"
+ : "=m" (tlong));
printk("tt0 is %#lx, ", tlong);
- asm volatile ("pmove %%tt1,%0@"
- : /* no outputs */
- : "a" (&tlong));
+ asm volatile ("pmove %%tt1,%0"
+ : "=m" (tlong));
printk("tt1 is %#lx\n", tlong);
#endif
#ifdef DEBUG
@@ -668,13 +666,13 @@
#ifdef DEBUG
asm volatile ("ptestr #1,%2@,#7,%0\n\t"
- "pmove %%psr,%1@"
- : "=a&" (desc)
- : "a" (&temp), "a" (addr));
+ "pmove %%psr,%1"
+ : "=a&" (desc), "=m" (temp)
+ : "a" (addr));
#else
asm volatile ("ptestr #1,%1@,#7\n\t"
- "pmove %%psr,%0@"
- : : "a" (&temp), "a" (addr));
+ "pmove %%psr,%0"
+ : "=m" (temp) : "a" (addr));
#endif
mmusr = temp;