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| author | Andreas Schwab <schwab@linux-m68k.org> | 2012-07-28 00:20:34 +0200 |
|---|---|---|
| committer | Geert Uytterhoeven <geert@linux-m68k.org> | 2012-08-03 00:48:24 +0200 |
| commit | 9e2760d18b3cf179534bbc27692c84879c61b97c (patch) | |
| tree | 2b2b308f8ff8db41b3ecec941f3f5caf1aac62e8 | |
| parent | 1525e06e4414dbe053ea10cbd8cc03bb150e8e27 (diff) | |
| download | linux-3.10-9e2760d18b3cf179534bbc27692c84879c61b97c.tar.gz linux-3.10-9e2760d18b3cf179534bbc27692c84879c61b97c.tar.bz2 linux-3.10-9e2760d18b3cf179534bbc27692c84879c61b97c.zip | |
m68k: Make sys_atomic_cmpxchg_32 work on classic m68k
User space access must always go through uaccess accessors, since on
classic m68k user space and kernel space are completely separate.
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Tested-by: Thorsten Glaser <tg@debian.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: stable@vger.kernel.org
| -rw-r--r-- | arch/m68k/kernel/sys_m68k.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/arch/m68k/kernel/sys_m68k.c b/arch/m68k/kernel/sys_m68k.c index 8623f8dc16f..9a5932ec368 100644 --- a/arch/m68k/kernel/sys_m68k.c +++ b/arch/m68k/kernel/sys_m68k.c @@ -479,9 +479,13 @@ sys_atomic_cmpxchg_32(unsigned long newval, int oldval, int d3, int d4, int d5, goto bad_access; } - mem_value = *mem; + /* + * No need to check for EFAULT; we know that the page is + * present and writable. + */ + __get_user(mem_value, mem); if (mem_value == oldval) - *mem = newval; + __put_user(newval, mem); pte_unmap_unlock(pte, ptl); up_read(&mm->mmap_sem); |