This is a note to let you know that I've just added the patch titled
m68k: Fix assembler constraint to prevent overeager gcc optimisation
to the 3.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
m68k-fix-assembler-constraint-to-prevent-overeager-gcc-optimisation.patch
and it can be found in the queue-3.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 2a3535069e33d8b416f406c159ce924427315303 Mon Sep 17 00:00:00 2001
From: Andreas Schwab <[email protected]>
Date: Mon, 9 Jan 2012 15:10:15 +0100
Subject: m68k: Fix assembler constraint to prevent overeager gcc optimisation
From: Andreas Schwab <[email protected]>
commit 2a3535069e33d8b416f406c159ce924427315303 upstream.
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 <[email protected]>
Signed-off-by: Geert Uytterhoeven <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
arch/m68k/atari/config.c | 8 ++++----
arch/m68k/kernel/process_mm.c | 4 ++--
arch/m68k/kernel/process_no.c | 4 ++--
arch/m68k/kernel/traps.c | 36 +++++++++++++++++-------------------
arch/m68k/mm/cache.c | 6 +++---
5 files changed, 28 insertions(+), 30 deletions(-)
--- a/arch/m68k/atari/config.c
+++ b/arch/m68k/atari/config.c
@@ -414,9 +414,9 @@ void __init config_atari(void)
* FDC val = 4 -> Supervisor only */
asm volatile ("\n"
" .chip 68030\n"
- " pmove %0@,%/tt1\n"
+ " pmove %0,%/tt1\n"
" .chip 68k"
- : : "a" (&tt1_val));
+ : : "m" (tt1_val));
} else {
asm volatile ("\n"
" .chip 68040\n"
@@ -569,10 +569,10 @@ static void atari_reset(void)
: "d0");
} else
asm volatile ("\n"
- " pmove %0@,%%tc\n"
+ " pmove %0,%%tc\n"
" jmp %1@"
: /* no outputs */
- : "a" (&tc_val), "a" (reset_addr));
+ : "m" (tc_val), "a" (reset_addr));
}
--- 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));
}
/*
--- 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
}
--- a/arch/m68k/kernel/traps.c
+++ b/arch/m68k/kernel/traps.c
@@ -552,13 +552,13 @@ static inline void bus_error030 (struct
#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
!(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
#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;
--- a/arch/m68k/mm/cache.c
+++ b/arch/m68k/mm/cache.c
@@ -52,9 +52,9 @@ static unsigned long virt_to_phys_slow(u
unsigned long *descaddr;
asm volatile ("ptestr %3,%2@,#7,%0\n\t"
- "pmove %%psr,%1@"
- : "=a&" (descaddr)
- : "a" (&mmusr), "a" (vaddr), "d" (get_fs().seg));
+ "pmove %%psr,%1"
+ : "=a&" (descaddr), "=m" (mmusr)
+ : "a" (vaddr), "d" (get_fs().seg));
if (mmusr & (MMU_I|MMU_B|MMU_L))
return 0;
descaddr = phys_to_virt((unsigned long)descaddr);
Patches currently in stable-queue which might be from [email protected] are
queue-3.2/m68k-fix-assembler-constraint-to-prevent-overeager-gcc-optimisation.patch
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