From: stsp@list•ru (Stas Sergeev)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] n_tty: use kmalloc() instead of vmalloc() to avoid crash on armada-xp
Date: Wed, 11 Mar 2015 20:26:53 +0300 [thread overview]
Message-ID: <55007ADD.6080505@list.ru> (raw)
In-Reply-To: <20150311175227.499612af@free-electrons.com>
11.03.2015 19:52, Thomas Petazzoni ?????:
> Dear Stas Sergeev,
> No, this is not the right fix. The right fix is to upgrade your
> bootloader to a non-buggy one.
>
> Basically, the problem is that the memory information passed by the
> bootloader to the kernel is not consistent with the MBus base address
> which is the limit between RAM (below the MBus base address) and I/O
> registers (above the MBus base address).
>
> The bootloader tells the kernel that the RAM up to 0xf0000000 is
> usable, but sets the MBus base address to 0xe0000000. So whenever the
> kernel accesses 0xe0000000 -> 0xf0000000, it crashes, because you're
> not hitting RAM but MBus windows (and there are most likely no MBus
> window mapped in this space).
>
> Since kmalloc() relies on the identity mapping, it happens to mainly
> use pages at the beginning of the physical memory, which are OK. But
> vmalloc() happens to start using pages at the end of the physical
> memory (which are not part of the identity mapping), so that's why
> you're seeing this on the first access to a vmalloc()ed area.
>
> This problem has already been reported to Marvell and they have fixed
> it in their U-Boot. Please upgrade your bootloader, since there is not
> much the kernel can do about this: the bootloader is simply lying to
> the kernel about the amount of memory that is accessible.
Hello Thomas, thanks for that info!
Is there a quick way to test that?
I used memmap=0x20000000$0xe0000000 but nothing changed...
next prev parent reply other threads:[~2015-03-11 17:26 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-10 16:54 [PATCH] n_tty: use kmalloc() instead of vmalloc() to avoid crash on armada-xp Stas Sergeev
2015-03-10 17:17 ` Catalin Marinas
2015-03-10 17:27 ` Stas Sergeev
2015-03-10 17:38 ` Russell King - ARM Linux
2015-03-10 18:31 ` Stas Sergeev
2015-03-10 18:54 ` Russell King - ARM Linux
2015-03-11 12:30 ` Stas Sergeev
2015-03-11 12:47 ` Russell King - ARM Linux
2015-03-11 14:24 ` Stas Sergeev
2015-03-11 16:30 ` Peter Hurley
2015-03-11 16:39 ` Stas Sergeev
2015-03-12 12:33 ` Peter Hurley
2015-03-12 12:47 ` Stas Sergeev
2015-03-12 13:04 ` Russell King - ARM Linux
2015-03-12 13:11 ` Stas Sergeev
2015-03-12 15:34 ` Vladimir Murzin
2015-03-12 12:59 ` Russell King - ARM Linux
2015-03-10 17:29 ` Russell King - ARM Linux
2015-03-10 17:35 ` Peter Hurley
2015-03-10 17:51 ` Stas Sergeev
2015-03-10 18:45 ` Peter Hurley
2015-03-11 12:44 ` Gregory CLEMENT
2015-03-11 12:57 ` Stas Sergeev
2015-03-11 13:14 ` Russell King - ARM Linux
2015-03-11 14:33 ` Stas Sergeev
2015-03-11 15:01 ` Stas Sergeev
2015-03-11 15:13 ` Gregory CLEMENT
2015-03-11 15:22 ` Stas Sergeev
2015-03-12 13:06 ` Russell King - ARM Linux
2015-03-11 16:52 ` Thomas Petazzoni
2015-03-11 17:26 ` Stas Sergeev [this message]
2015-03-11 17:46 ` Russell King - ARM Linux
2015-03-11 17:56 ` Stas Sergeev
2015-03-11 18:11 ` Thomas Petazzoni
2015-03-11 18:38 ` Stas Sergeev
2015-03-11 18:41 ` Russell King - ARM Linux
2015-03-11 18:08 ` Stas Sergeev
2015-03-11 18:33 ` Thomas Petazzoni
2015-03-12 12:44 ` Stas Sergeev
2015-03-12 12:47 ` Thomas Petazzoni
2015-03-12 13:03 ` Stas Sergeev
2015-03-12 13:12 ` Russell King - ARM Linux
2015-03-12 13:16 ` Stas Sergeev
2015-03-12 13:55 ` Thomas Petazzoni
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