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  1. 29 Mar, 2010 3 commits
    • Ian Campbell's avatar
      x86: Do not free zero sized per cpu areas · eed63519
      Ian Campbell authored 
      This avoids an infinite loop in free_early_partial().

Add a warning to free_early_partial() to catch future problems.

-v5: put back start > end back into WARN_ONCE()
-v6: use one line for warning, suggested by Linus
-v7: more tests
-v8: remove the function name as suggested by Johannes
     WARN_ONCE() will print out that function name.
Signed-off-by: default avatarIan Campbell <ian.campbell@citrix.com>
Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Tested-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: default avatarJoel Becker <joel.becker@oracle.com>
Tested-by: default avatarStanislaw Gruszka <sgruszka@redhat.com>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <1269830604-26214-4-git-send-email-yinghai@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      eed63519
    • Yinghai Lu's avatar
      x86: Make sure free_init_pages() frees pages on page boundary · c967da6a
      Yinghai Lu authored 
      When CONFIG_NO_BOOTMEM=y, it could use memory more effiently, or
in a more compact fashion.

Example:

 Allocated new RAMDISK: 00ec2000 - 0248ce57
 Move RAMDISK from 000000002ea04000 - 000000002ffcee56 to 00ec2000 - 0248ce56

The new RAMDISK's end is not page aligned.
Last page could be shared with other users.

When free_init_pages are called for initrd or .init, the page
could be freed and we could corrupt other data.

code segment in free_init_pages():

 |        for (; addr < end; addr += PAGE_SIZE) {
 |                ClearPageReserved(virt_to_page(addr));
 |                init_page_count(virt_to_page(addr));
 |                memset((void *)(addr & ~(PAGE_SIZE-1)),
 |                        POISON_FREE_INITMEM, PAGE_SIZE);
 |                free_page(addr);
 |                totalram_pages++;
 |        }

last half page could be used as one whole free page.

So page align the boundaries.

-v2: make the original initramdisk to be aligned, according to
     Johannes, otherwise we have the chance to lose one page.
     we still need to keep initrd_end not aligned, otherwise it could
     confuse decompressor.
-v3: change to WARN_ON instead, suggested by Johannes.
-v4: use PAGE_ALIGN, suggested by Johannes.
     We may fix that macro name later to PAGE_ALIGN_UP, and PAGE_ALIGN_DOWN
     Add comments about assuming ramdisk start is aligned
     in relocate_initrd(), change to re get ramdisk_image instead of save it
     to make diff smaller. Add warning for wrong range, suggested by Johannes.
-v6: remove one WARN()
     We need to align beginning in free_init_pages()
     do not copy more than ramdisk_size, noticed by Johannes
Reported-by: default avatarStanislaw Gruszka <sgruszka@redhat.com>
Tested-by: default avatarStanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Cc: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <1269830604-26214-3-git-send-email-yinghai@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      c967da6a
    • Yinghai Lu's avatar
      x86: Make smp_locks end with page alignment · 596b711e
      Yinghai Lu authored 
      Fix:

 ------------[ cut here ]------------
 WARNING: at arch/x86/mm/init.c:342 free_init_pages+0x4c/0xfa()
 free_init_pages: range [0x40daf000, 0x40db5c24] is not aligned
 Modules linked in:
 Pid: 0, comm: swapper Not tainted
 2.6.34-rc2-tip-03946-g4f16b23-dirty #50 Call Trace:
  [<40232e9f>] warn_slowpath_common+0x65/0x7c
  [<4021c9f0>] ? free_init_pages+0x4c/0xfa
  [<40881434>] ? _etext+0x0/0x24
  [<40232eea>] warn_slowpath_fmt+0x24/0x27
  [<4021c9f0>] free_init_pages+0x4c/0xfa
  [<40881434>] ? _etext+0x0/0x24
  [<40d3f4bd>] alternative_instructions+0xf6/0x100
  [<40d3fe4f>] check_bugs+0xbd/0xbf
  [<40d398a7>] start_kernel+0x2d5/0x2e4
  [<40d390ce>] i386_start_kernel+0xce/0xd5
 ---[ end trace 4eaa2a86a8e2da22 ]---

Comments in vmlinux.lds.S already said:

 |        /*
 |         * smp_locks might be freed after init
 |         * start/end must be page aligned
 |         */
Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Cc: David Miller <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <1269830604-26214-2-git-send-email-yinghai@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      596b711e
  3. 26 Mar, 2010 13 commits
  5. 25 Mar, 2010 20 commits
  7. 24 Mar, 2010 4 commits
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