On Mon, Oct 14, 2013 at 02:05:44PM +0200, Jonas Gorski wrote:
> On Mon, Sep 23, 2013 at 4:10 PM, Ashok Kumar <ashoks@xxxxxxxxxxxx> wrote:
> > When initrd is present in the PFN right after the _end, bootmem
> > bitmap(mapstart) overwrites it. So check for initrd_end in
> > mapstart calculation.
> >
> > Signed-off-by: Ashok Kumar <ashoks@xxxxxxxxxxxx>
> > ---
> > This is seen after the commit
> > "mips: fix start of free memory when using initrd"
> > in git://git.linux-mips.org/pub/scm/ralf/upstream-sfr.git branch
> >
> > Tested the image on MIPS platform creating the above
> > said scenario and initrd was corrupted.
>
> Unfortunately this commit breaks booting ramdisk images on bcm63xx, at
> least git bisect claims it to be responsible for:
>
> Closing DMA Channels.
> Starting program at 0x80284b60
> [ 0.000000] Linux version 3.12.0-rc4+ (jonas@ixxyvirt) (gcc version
> 4.8.) #254 SMP Mon Oct 14 13:12:35 CEST 2013
> [ 0.000000] Detected Broadcom 0x6328 CPU revision b0
> [ 0.000000] CPU frequency is 320 MHz
> [ 0.000000] 128MB of RAM installed
> [ 0.000000] registering 32 GPIOs
> [ 0.000000] board_bcm963xx: CFE version: 1.0.37-106.17
> [ 0.000000] bootconsole [early0] enabled
> [ 0.000000] CPU revision is: 0002a075 (Broadcom BMIPS4350)
> [ 0.000000] board_bcm963xx: board name: 96328avng
> [ 0.000000] Determined physical RAM map:
> [ 0.000000] memory: 08000000 @ 00000000 (usable)
> **Exception 8: EPC=00000000, Cause=00000000 (Interrupt)
> RA=00000000, VAddr=00000000
>
> 0 ($00) = 8016E5F4 AT ($01) = 00000000
> v0 ($02) = 00000000 v1 ($03) = 0000000A
> a0 ($04) = FFFFFFFF a1 ($05) = 0006FFFF
> a2 ($06) = 00000000 a3 ($07) = 803D6730
> t0 ($08) = 0000002A t1 ($09) = 00000000
> t2 ($10) = 802D5203 t3 ($11) = 8029D2F8
> t4 ($12) = 803D6737 t5 ($13) = 802D5203
> t6 ($14) = 00000000 t7 ($15) = 8030BD68
> s0 ($16) = 8016E5F4 s1 ($17) = 803D6737
> s2 ($18) = 802D5203 s3 ($19) = 8029D2F8
> s4 ($20) = 8030BD90 s5 ($21) = 8016E5F4
> s6 ($22) = 00000001 s7 ($23) = 803D6730
> t8 ($24) = 0000000A t9 ($25) = FFFFFFFF
> k0 ($26) = 0006FFFF k1 ($27) = 8016EF08
> gp ($28) = 803F0000 sp ($29) = 8001DAC0
> fp ($30) = 0000001D ra ($31) = 00000000
>
>
> Probably relevant config parts are:
>
> CONFIG_BLK_DEV_INITRD=y
> CONFIG_INITRAMFS_SOURCE="/home/jonas/openwrt/trunk/build_dir/target-mips_mips32_uClibc-0.9.33.2/root-brcm63xx
> /home/jonas/openwrt/trunk/target/linux/generic/image/initramfs-base-files.txt"
> CONFIG_INITRAMFS_ROOT_UID=1000
> CONFIG_INITRAMFS_ROOT_GID=1000
> # CONFIG_RD_GZIP is not set
> # CONFIG_RD_BZIP2 is not set
> # CONFIG_RD_LZMA is not set
> CONFIG_RD_XZ=y
> # CONFIG_RD_LZO is not set
> # CONFIG_RD_LZ4 is not set
> # CONFIG_INITRAMFS_COMPRESSION_NONE is not set
> CONFIG_INITRAMFS_COMPRESSION_XZ=y
>
> > arch/mips/kernel/setup.c | 5 +++++
> > 1 files changed, 5 insertions(+), 0 deletions(-)
> >
> > diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
> > index 5342385..dfb8585 100644
> > --- a/arch/mips/kernel/setup.c
> > +++ b/arch/mips/kernel/setup.c
> > @@ -364,6 +364,11 @@ static void __init bootmem_init(void)
> > }
> >
> > /*
> > + * mapstart should be after initrd_end
> > + */
> > + mapstart = max(mapstart, (unsigned long)PFN_UP(__pa(initrd_end)));
>
> I wonder if this still holds if the initrd is compressed like in my
> config, but that's just random guessing. I can't test it since I need
> a compressed initrd, else the elf gets too big for CFE.
when initramfs(compressed/uncompressed) is used and initrd is not used,
initrd_end should be zero. In 32-bit kernel __pa(0) becomes 0x80000000
and mapstart points to wrong address. Added check for non zero initrd_end
before finding max.
I have tested the below patch on XLP 32-bit BE/LE, 64-bit BE/LE and
it works fine. could you please test this on your bcm63xx board.
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 9d5d31d..a842154 100644
--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -367,7 +367,8 @@ static void __init bootmem_init(void)
/*
* mapstart should be after initrd_end
*/
- mapstart = max(mapstart, (unsigned long)PFN_UP(__pa(initrd_end)));
+ if (initrd_end)
+ mapstart = max(mapstart, (unsigned long)PFN_UP(__pa(initrd_end)));
#endif
- Ashok
>
> > +
> > + /*
> > * Initialize the boot-time allocator with low memory only.
> > */
> > bootmap_size = init_bootmem_node(NODE_DATA(0), mapstart,
>
>
> Regards
> Jonas
>
