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authorAndreas Schwab <schwab@linux-m68k.org>2012-01-09 15:10:15 +0100
committerGeert Uytterhoeven <geert@linux-m68k.org>2012-01-22 14:50:20 +0100
commit2a3535069e33d8b416f406c159ce924427315303 (patch)
tree2de8aa3a94215260fe91b0edb1c8f5d685413d04 /arch/m68k/kernel
parentc808d3d839ab70c87a6c9356c50569c87661378e (diff)
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
Diffstat (limited to 'arch/m68k/kernel')
-rw-r--r--arch/m68k/kernel/process_mm.c4
-rw-r--r--arch/m68k/kernel/process_no.c4
-rw-r--r--arch/m68k/kernel/traps.c36
3 files changed, 21 insertions, 23 deletions
diff --git a/arch/m68k/kernel/process_mm.c b/arch/m68k/kernel/process_mm.c
index 1bc223aa07ec..aa4ffb882366 100644
--- a/arch/m68k/kernel/process_mm.c
+++ b/arch/m68k/kernel/process_mm.c
@@ -189,8 +189,8 @@ void flush_thread(void)
current->thread.fs = __USER_DS;
if (!FPU_IS_EMU)
asm volatile (".chip 68k/68881\n\t"
- "frestore %0@\n\t"
- ".chip 68k" : : "a" (&zero));
+ "frestore %0\n\t"
+ ".chip 68k" : : "m" (zero));
}
/*
diff --git a/arch/m68k/kernel/process_no.c b/arch/m68k/kernel/process_no.c
index 69c1803fcf1b..5e1078cabe0e 100644
--- a/arch/m68k/kernel/process_no.c
+++ b/arch/m68k/kernel/process_no.c
@@ -163,8 +163,8 @@ void flush_thread(void)
#ifdef CONFIG_FPU
if (!FPU_IS_EMU)
asm volatile (".chip 68k/68881\n\t"
- "frestore %0@\n\t"
- ".chip 68k" : : "a" (&zero));
+ "frestore %0\n\t"
+ ".chip 68k" : : "m" (zero));
#endif
}
diff --git a/arch/m68k/kernel/traps.c b/arch/m68k/kernel/traps.c
index 89362f2bb56a..eb6746978083 100644
--- a/arch/m68k/kernel/traps.c
+++ b/arch/m68k/kernel/traps.c
@@ -552,13 +552,13 @@ static inline void bus_error030 (struct frame *fp)
#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 @@ static inline void bus_error030 (struct frame *fp)
!(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 @@ static inline void bus_error030 (struct frame *fp)
#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;