On Thu, Jan 31, 2019 at 07:15:26AM +0100, Christophe Leroy wrote:
>
>
> Le 31/01/2019 à 07:06, Stephen Rothwell a écrit :
> >Hi all,
> >
> >On Thu, 31 Jan 2019 16:38:54 +1100 Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
> >>
> >>[I am guessing that is is something in Andrew's tree that has caused
> >>this.]
> >>
> >>My qemu boot of the powerpc pseries_le_defconfig config failed like this:
> >>
> >>htab_hash_mask = 0x1ffff
> >>-----------------------------------------------------
> >>numa: NODE_DATA [mem 0x7ffe7000-0x7ffebfff]
> >>Kernel panic - not syncing: sparse_buffer_init: Failed to allocate 2147483648 bytes align=0x10000 nid=0 from=fffffffffffffff
This means that sparse_buffer_init tries to allocate 2G for the sparsemap_buf...
Stephen, how many memory do you give to your VM?
> >>CPU: 0 PID: 0 Comm: swapper Not tainted 5.0.0-rc4 #2
> >>Call Trace:
> >>[c00000000105bbd0] [c000000000b1345c] dump_stack+0xb0/0xf4 (unreliable)
> >>[c00000000105bc10] [c000000000111120] panic+0x168/0x3b8
> >>[c00000000105bcb0] [c000000000e701c8] sparse_init_nid+0x178/0x550
> >>[c00000000105bd70] [c000000000e709b4] sparse_init+0x210/0x238
> >>[c00000000105bdb0] [c000000000e468f4] initmem_init+0x1e0/0x260
> >>[c00000000105be80] [c000000000e3b9b0] setup_arch+0x354/0x3d4
> >>[c00000000105bef0] [c000000000e33afc] start_kernel+0x98/0x648
> >>[c00000000105bf90] [c00000000000b270] start_here_common+0x1c/0x52c
> >
> >A quick bisect leads to this:
> >
> >1c3c9328cde027eb875ba4692f0a5d66b0afe862 is the first bad commit
> >commit 1c3c9328cde027eb875ba4692f0a5d66b0afe862
> >Author: Mike Rapoport <rppt@xxxxxxxxxxxxx>
> >Date: Thu Jan 31 10:51:32 2019 +1100
> >
> > treewide: add checks for the return value of memblock_alloc*()
> > Add check for the return value of memblock_alloc*() functions and call
> > panic() in case of error. The panic message repeats the one used by
> > panicing memblock allocators with adjustment of parameters to include only
> > relevant ones.
> > The replacement was mostly automated with semantic patches like the one
> > below with manual massaging of format strings.
> > @@
> > expression ptr, size, align;
> > @@
> > ptr = memblock_alloc(size, align);
> > + if (!ptr)
> > + panic("%s: Failed to allocate %lu bytes align=0x%lx\n", __func__,
> > size, align);
> > Link: http://lkml.kernel.org/r/1548057848-15136-20-git-send-email-rppt@xxxxxxxxxxxxx
> > Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx>
> > Reviewed-by: Guo Ren <ren_guo@xxxxxxxxx> [c-sky]
> > Acked-by: Paul Burton <paul.burton@xxxxxxxx> [MIPS]
> > Acked-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx> [s390]
> > Reviewed-by: Juergen Gross <jgross@xxxxxxxx> [Xen]
> > Reviewed-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> [m68k]
> > Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> > Cc: Christophe Leroy <christophe.leroy@xxxxxx>
> > Cc: Christoph Hellwig <hch@xxxxxx>
> > Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> > Cc: Dennis Zhou <dennis@xxxxxxxxxx>
> > Cc: Greentime Hu <green.hu@xxxxxxxxx>
> > Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > Cc: Guan Xuetao <gxt@xxxxxxxxxx>
> > Cc: Guo Ren <guoren@xxxxxxxxxx>
> > Cc: Mark Salter <msalter@xxxxxxxxxx>
> > Cc: Matt Turner <mattst88@xxxxxxxxx>
> > Cc: Max Filippov <jcmvbkbc@xxxxxxxxx>
> > Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> > Cc: Michal Simek <monstr@xxxxxxxxx>
> > Cc: Petr Mladek <pmladek@xxxxxxxx>
> > Cc: Richard Weinberger <richard@xxxxxx>
> > Cc: Rich Felker <dalias@xxxxxxxx>
> > Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> > Cc: Rob Herring <robh@xxxxxxxxxx>
> > Cc: Russell King <linux@xxxxxxxxxxxxxxx>
> > Cc: Stafford Horne <shorne@xxxxxxxxx>
> > Cc: Tony Luck <tony.luck@xxxxxxxxx>
> > Cc: Vineet Gupta <vgupta@xxxxxxxxxxxx>
> > Cc: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
> > Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> >
> >Which is just adding the panic we hit. So, presumably, the bug is in a
> >preceding patch :-(
> >
> >I have left the kernel not booting for today.
> >
>
> No I think the error is really in that patch, see my other mail.
>
> See https://elixir.bootlin.com/linux/v5.0-rc4/source/mm/memblock.c#L1455,
> memblock_alloc_try_nid_raw() is not supposed to panic, so the last hunk of
> this patch should be reverted.
It is not supposed to panic, but it can still fail, so simply ignoring it's
return value seems a bit odd at least.
> Found in total three problematic hunks in that patch:
>
> @@ -48,6 +53,11 @@ static phys_addr_t __init kasan_alloc_raw_page(int node)
> void *p = memblock_alloc_try_nid_raw(PAGE_SIZE, PAGE_SIZE,
> __pa(MAX_DMA_ADDRESS),
> MEMBLOCK_ALLOC_KASAN, node);
> + if (!p)
> + panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%llx\n",
> + __func__, PAGE_SIZE, PAGE_SIZE, node,
> + __pa(MAX_DMA_ADDRESS));
> +
> return __pa(p);
> }
>
> @@ -211,6 +211,9 @@ static int __init iob_init(struct device_node *dn)
> iob_l2_base = memblock_alloc_try_nid_raw(1UL << 21, 1UL << 21,
> MEMBLOCK_LOW_LIMIT, 0x80000000,
> NUMA_NO_NODE);
> + if (!iob_l2_base)
> + panic("%s: Failed to allocate %lu bytes align=0x%lx max_addr=%x\n",
> + __func__, 1UL << 21, 1UL << 21, 0x80000000);
>
> pr_info("IOBMAP L2 allocated at: %p\n", iob_l2_base);
>
>
> @@ -425,6 +436,10 @@ static void __init sparse_buffer_init(unsigned long
> size, int nid)
> memblock_alloc_try_nid_raw(size, PAGE_SIZE,
> __pa(MAX_DMA_ADDRESS),
> MEMBLOCK_ALLOC_ACCESSIBLE, nid);
> + if (!sparsemap_buf)
> + panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%lx\n",
> + __func__, size, PAGE_SIZE, nid, __pa(MAX_DMA_ADDRESS));
> +
> sparsemap_buf_end = sparsemap_buf + size;
> }
>
>
>
> Christophe
>
--
Sincerely yours,
Mike.
