From 2a3535069e33d8b416f406c159ce924427315303 Mon Sep 17 00:00:00 2001 From: Andreas Schwab Date: Mon, 9 Jan 2012 15:10:15 +0100 Subject: 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 Signed-off-by: Geert Uytterhoeven Cc: stable@vger.kernel.org --- arch/m68k/kernel/process_mm.c | 4 ++-- arch/m68k/kernel/process_no.c | 4 ++-- arch/m68k/kernel/traps.c | 36 +++++++++++++++++------------------- 3 files changed, 21 insertions(+), 23 deletions(-) (limited to 'arch/m68k/kernel') 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; -- cgit v1.2.3