On Tue, Feb 12, 2019 at 04:12:24PM -0600, Rob Herring wrote:
> On Tue, Feb 12, 2019 at 3:50 PM Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
> >
> > Hi all,
> >
> > On Tue, 12 Feb 2019 10:03:09 -0600 Rob Herring <robh+dt@xxxxxxxxxx> wrote:
> > >
> > > On Mon, Feb 11, 2019 at 10:47 AM Marc Gonzalez <marc.w.gonzalez@xxxxxxx> wrote:
> > > >
> > > > On 04/02/2019 15:37, Marc Gonzalez wrote:
> > > >
> > > > > Cc: stable@xxxxxxxxxxxxxxx # 3.15+
> > > > > Fixes: 3f0c820664483 ("drivers: of: add initialization code for dynamic reserved memory")
> > > > > Acked-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> > > > > Acked-by: Prateek Patel <prpatel@xxxxxxxxxx>
> > > > > Tested-by: Marc Gonzalez <marc.w.gonzalez@xxxxxxx>
> > > > > Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
> > > > > ---
> > > > > Resend with DT CCed to reach robh's patch queue
> > > > > I added CC: stable, Fixes, and Prateek's ack
> > > > > Trim recipients list to minimize inconvenience
> > > >
> > > > I'm confused over commit 3532b3b554a216f30edb841d29eef48521bdc592 in linux-next
> > > > "memblock: drop __memblock_alloc_base()"
> > > >
> > > > It's definitely going to conflict with the proposed patch
> > > > over drivers/of/of_reserved_mem.c
> > > >
> > > > Rob, what's the next step then?
> > >
> > > Rebase it on top of what's in linux-next and apply it to the tree
> > > which has the above dependency. I'm guessing that is Andrew Morton's
> > > tree.
> >
> > Yeah, that is in Andrew's "post linux-next" patch series, so if you
> > rebase it on top of linux-next and then send it to Andrew with some
> > explanation.
> >
> > ...
> >
> > Actually, if it is intended for the stable trees, then presumably it is
> > intended to go to Linus for the current release? In which case, the
> > patch in Andrew's tree will have to be changed to cope after your patch
> > appears in Linus' tree (and therefore, linux-next).
>
> At this point in the cycle, I wasn't planning to send this for 5.0.
> It's not fixing something introduced in 5.0 and it is a debug feature.
Below is the version vs. current mmotm.
>From 9ea6dceb46067d4f1cbbdbec1189c8496aa0a4bc Mon Sep 17 00:00:00 2001
From: Mike Rapoport <rppt@xxxxxxxxxxxxx>
Date: Mon, 4 Feb 2019 15:37:21 +0100
Subject: [PATCH] of: fix kmemleak crash caused by imbalance in early memory
reservation
Marc Gonzalez reported the following kmemleak crash:
Unable to handle kernel paging request at virtual address ffffffc021e00000
Mem abort info:
ESR = 0x96000006
Exception class = DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
Data abort info:
ISV = 0, ISS = 0x00000006
CM = 0, WnR = 0
swapper pgtable: 4k pages, 39-bit VAs, pgdp = (____ptrval____)
[ffffffc021e00000] pgd=000000017e3ba803, pud=000000017e3ba803,
pmd=0000000000000000
Internal error: Oops: 96000006 [#1] PREEMPT SMP
Modules linked in:
CPU: 6 PID: 523 Comm: kmemleak Tainted: G S W 5.0.0-rc1 #13
Hardware name: Qualcomm Technologies, Inc. MSM8998 v1 MTP (DT)
pstate: 80000085 (Nzcv daIf -PAN -UAO)
pc : scan_block+0x70/0x190
lr : scan_block+0x6c/0x190
sp : ffffff8012e8bd20
x29: ffffff8012e8bd20 x28: ffffffc0fdbaf018
x27: ffffffc022000000 x26: 0000000000000080
x25: ffffff8011aadf70 x24: ffffffc0f8cc8000
x23: ffffff8010dc8000 x22: ffffff8010dc8830
x21: ffffffc021e00ff9 x20: ffffffc0f8cc8050
x19: ffffffc021e00000 x18: 0000000000002409
x17: 0000000000000200 x16: 0000000000000000
x15: ffffff8010e14dd8 x14: 0000000000002406
x13: 000000004c4dd0c6 x12: ffffffc0f77dad58
x11: 0000000000000001 x10: ffffff8010d9e688
x9 : ffffff8010d9f000 x8 : ffffff8010d9e688
x7 : 0000000000000002 x6 : 0000000000000000
x5 : ffffff8011511c20 x4 : 00000000000026d1
x3 : ffffff8010e14d88 x2 : 5b36396f4e7d4000
x1 : 0000000000208040 x0 : 0000000000000000
Process kmemleak (pid: 523, stack limit = 0x(____ptrval____))
Call trace:
scan_block+0x70/0x190
scan_gray_list+0x108/0x1c0
kmemleak_scan+0x33c/0x7c0
kmemleak_scan_thread+0x98/0xf0
kthread+0x11c/0x120
ret_from_fork+0x10/0x1c
Code: f9000fb4 d503201f 97ffffd2 35000580 (f9400260)
---[ end trace 176d6ed9d86a0c33 ]---
note: kmemleak[523] exited with preempt_count 2
The crash happens when a no-map area is allocated in
early_init_dt_alloc_reserved_memory_arch(). The allocated region is
registered with kmemleak, but it is then removed from memblock using
memblock_remove() that is not kmemleak-aware.
Replacing __memblock_alloc_base() with memblock_find_in_range() makes sure
that the allocated memory is not added to kmemleak and then
memblock_remove()'ing this memory is safe.
As a bonus, since memblock_find_in_range() ensures the allocation in the
specified range, the bounds check can be removed.
Cc: stable@xxxxxxxxxxxxxxx # 3.15+
Fixes: 3f0c820664483 ("drivers: of: add initialization code for dynamic reserved memory")
Acked-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Acked-by: Prateek Patel <prpatel@xxxxxxxxxx>
Tested-by: Marc Gonzalez <marc.w.gonzalez@xxxxxxx>
Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
---
drivers/of/of_reserved_mem.c | 13 ++++---------
1 file changed, 4 insertions(+), 9 deletions(-)
diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 78aa9eb..47971ab 100644
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -34,21 +34,16 @@ int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
align = !align ? SMP_CACHE_BYTES : align;
- base = memblock_phys_alloc_range(size, align, 0, end);
+ base = memblock_find_in_range(size, align, start, end);
if (!base)
return -ENOMEM;
- /*
- * Check if the allocated region fits in to start..end window
- */
- if (base < start) {
- memblock_free(base, size);
- return -ENOMEM;
- }
-
*res_base = base;
if (nomap)
return memblock_remove(base, size);
+ else
+ return memblock_reserve(base, size);
+
return 0;
}
--
2.7.4
