Merge branch 'x86-geode-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...

[pandora-kernel.git] / arch / x86 / kernel / sys_x86_64.c

diff --git a/arch/x86/kernel/sys_x86_64.c b/arch/x86/kernel/sys_x86_64.c
index ff14a50..0514890 100644 (file)
--- a/arch/x86/kernel/sys_x86_64.c
+++ b/arch/x86/kernel/sys_x86_64.c
@@ -14,10 +14,73 @@
 #include <linux/personality.h>
 #include <linux/random.h>
 #include <linux/uaccess.h>
+#include <linux/elf.h>
 
 #include <asm/ia32.h>
 #include <asm/syscalls.h>
 
+/*
+ * Align a virtual address to avoid aliasing in the I$ on AMD F15h.
+ *
+ * @flags denotes the allocation direction - bottomup or topdown -
+ * or vDSO; see call sites below.
+ */
+unsigned long align_addr(unsigned long addr, struct file *filp,
+                        enum align_flags flags)
+{
+       unsigned long tmp_addr;
+
+       /* handle 32- and 64-bit case with a single conditional */
+       if (va_align.flags < 0 || !(va_align.flags & (2 - mmap_is_ia32())))
+               return addr;
+
+       if (!(current->flags & PF_RANDOMIZE))
+               return addr;
+
+       if (!((flags & ALIGN_VDSO) || filp))
+               return addr;
+
+       tmp_addr = addr;
+
+       /*
+        * We need an address which is <= than the original
+        * one only when in topdown direction.
+        */
+       if (!(flags & ALIGN_TOPDOWN))
+               tmp_addr += va_align.mask;
+
+       tmp_addr &= ~va_align.mask;
+
+       return tmp_addr;
+}
+
+static int __init control_va_addr_alignment(char *str)
+{
+       /* guard against enabling this on other CPU families */
+       if (va_align.flags < 0)
+               return 1;
+
+       if (*str == 0)
+               return 1;
+
+       if (*str == '=')
+               str++;
+
+       if (!strcmp(str, "32"))
+               va_align.flags = ALIGN_VA_32;
+       else if (!strcmp(str, "64"))
+               va_align.flags = ALIGN_VA_64;
+       else if (!strcmp(str, "off"))
+               va_align.flags = 0;
+       else if (!strcmp(str, "on"))
+               va_align.flags = ALIGN_VA_32 | ALIGN_VA_64;
+       else
+               return 0;
+
+       return 1;
+}
+__setup("align_va_addr", control_va_addr_alignment);
+
 SYSCALL_DEFINE6(mmap, unsigned long, addr, unsigned long, len,
                unsigned long, prot, unsigned long, flags,
                unsigned long, fd, unsigned long, off)
@@ -92,6 +155,9 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
        start_addr = addr;
 
 full_search:
+
+       addr = align_addr(addr, filp, 0);
+
        for (vma = find_vma(mm, addr); ; vma = vma->vm_next) {
                /* At this point:  (!vma || addr < vma->vm_end). */
                if (end - len < addr) {
@@ -117,6 +183,7 @@ full_search:
                        mm->cached_hole_size = vma->vm_start - addr;
 
                addr = vma->vm_end;
+               addr = align_addr(addr, filp, 0);
        }
 }
 
@@ -161,10 +228,13 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
 
        /* make sure it can fit in the remaining address space */
        if (addr > len) {
-               vma = find_vma(mm, addr-len);
-               if (!vma || addr <= vma->vm_start)
+               unsigned long tmp_addr = align_addr(addr - len, filp,
+                                                   ALIGN_TOPDOWN);
+
+               vma = find_vma(mm, tmp_addr);
+               if (!vma || tmp_addr + len <= vma->vm_start)
                        /* remember the address as a hint for next time */
-                       return mm->free_area_cache = addr-len;
+                       return mm->free_area_cache = tmp_addr;
        }
 
        if (mm->mmap_base < len)
@@ -173,6 +243,8 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
        addr = mm->mmap_base-len;
 
        do {
+               addr = align_addr(addr, filp, ALIGN_TOPDOWN);
+
                /*
                 * Lookup failure means no vma is above this address,
                 * else if new region fits below vma->vm_start,