linux-stable.git/arch/mips/kernel/setup.c, branch v4.4.232

MIPS: Make sparse_init() using top-down allocation

2020-06-20T08:23:20+00:00

[ Upstream commit 269b3a9ac538c4ae87f84be640b9fa89914a2489 ]

In the current code, if CONFIG_SWIOTLB is set, when failed to get IO TLB
memory from the low pages by plat_swiotlb_setup(), it may lead to the boot
process failed with kernel panic.

(1) On the Loongson and SiByte platform
arch/mips/loongson64/dma.c
arch/mips/sibyte/common/dma.c
void __init plat_swiotlb_setup(void)
{
	swiotlb_init(1);
}

kernel/dma/swiotlb.c
void  __init
swiotlb_init(int verbose)
{
...
	vstart = memblock_alloc_low(PAGE_ALIGN(bytes), PAGE_SIZE);
	if (vstart && !swiotlb_init_with_tbl(vstart, io_tlb_nslabs, verbose))
		return;
...
	pr_warn("Cannot allocate buffer");
	no_iotlb_memory = true;
}

phys_addr_t swiotlb_tbl_map_single()
{
...
	if (no_iotlb_memory)
		panic("Can not allocate SWIOTLB buffer earlier ...");
...
}

(2) On the Cavium OCTEON platform
arch/mips/cavium-octeon/dma-octeon.c
void __init plat_swiotlb_setup(void)
{
...
	octeon_swiotlb = memblock_alloc_low(swiotlbsize, PAGE_SIZE);
	if (!octeon_swiotlb)
		panic("%s: Failed to allocate %zu bytes align=%lx\n",
		      __func__, swiotlbsize, PAGE_SIZE);
...
}

Because IO_TLB_DEFAULT_SIZE is 64M, if the rest size of low memory is less
than 64M when call plat_swiotlb_setup(), we can easily reproduce the panic
case.

In order to reduce the possibility of kernel panic when failed to get IO
TLB memory under CONFIG_SWIOTLB, it is better to allocate low memory as
small as possible before plat_swiotlb_setup(), so make sparse_init() using
top-down allocation.

Reported-by: Juxin Gao 
Co-developed-by: Juxin Gao 
Signed-off-by: Juxin Gao 
Signed-off-by: Tiezhu Yang 
Signed-off-by: Thomas Bogendoerfer 
Signed-off-by: Sasha Levin

MIPS: Fix macro typo

2020-05-10T08:25:40+00:00

commit 2549cc967ebb4043f3507b55e3dc579f44d3b516 upstream.

Change the CONFIG_MIPS_CMDLINE_EXTEND to CONFIG_MIPS_CMDLINE_DTB_EXTEND
to resolve the EXTEND_WITH_PROM macro.

Signed-off-by: Jaedon Shin 
Fixes: 2024972ef533 ("MIPS: Make the kernel arguments from dtb available")
Reviewed-by: Alexander Sverdlin 
Cc: Jonas Gorski 
Cc: Masahiro Yamada 
Cc: Paul Burton 
Cc: Aaro Koskinen 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11909/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

mips: avoid explicit UB in assignment of mips_io_port_base

2020-01-29T09:21:47+00:00

[ Upstream commit 12051b318bc3ce5b42d6d786191008284b067d83 ]

The code in question is modifying a variable declared const through
pointer manipulation.  Such code is explicitly undefined behavior, and
is the lone issue preventing malta_defconfig from booting when built
with Clang:

If an attempt is made to modify an object defined with a const-qualified
type through use of an lvalue with non-const-qualified type, the
behavior is undefined.

LLVM is removing such assignments. A simple fix is to not declare
variables const that you plan on modifying.  Limiting the scope would be
a better method of preventing unwanted writes to such a variable.

Further, the code in question mentions "compiler bugs" without any links
to bug reports, so it is difficult to know if the issue is resolved in
GCC. The patch was authored in 2006, which would have been GCC 4.0.3 or
4.1.1. The minimal supported version of GCC in the Linux kernel is
currently 4.6.

For what its worth, there was UB before the commit in question, it just
added a barrier and got lucky IRT codegen. I don't think there's any
actual compiler bugs related, just runtime bugs due to UB.

Link: https://github.com/ClangBuiltLinux/linux/issues/610
Fixes: 966f4406d903 ("[MIPS] Work around bad code generation for .")
Reported-by: Nathan Chancellor 
Debugged-by: Nathan Chancellor 
Suggested-by: Eli Friedman 
Signed-off-by: Nick Desaulniers 
Reviewed-by: Nathan Chancellor 
Tested-by: Nathan Chancellor 
Signed-off-by: Paul Burton 
Cc: ralf@linux-mips.org
Cc: jhogan@kernel.org
Cc: Maciej W. Rozycki 
Cc: Hassan Naveed 
Cc: Stephen Kitt 
Cc: Serge Semin 
Cc: Mike Rapoport 
Cc: Andrew Morton 
Cc: Michal Hocko 
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: clang-built-linux@googlegroups.com
Signed-off-by: Sasha Levin

MIPS: init: Ensure reserved memory regions are not added to bootmem

2017-11-21T08:21:22+00:00

[ Upstream commit e89ef66d7682f031f026eee6bba03c8c2248d2a9 ]

Memories managed through boot_mem_map are generally expected to define
non-crossing areas. However, if part of a larger memory block is marked
as reserved, it would still be added to bootmem allocator as an
available block and could end up being overwritten by the allocator.

Prevent this by explicitly marking the memory as reserved it if exists
in the range used by bootmem allocator.

Signed-off-by: Marcin Nowakowski 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14608/
Signed-off-by: Ralf Baechle 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

MIPS: init: Ensure bootmem does not corrupt reserved memory

2017-11-21T08:21:22+00:00

[ Upstream commit d9b5b658210f28ed9f70c757d553e679d76e2986 ]

Current init code initialises bootmem allocator with all of the low
memory that it assumes is available, but does not check for reserved
memory block, which can lead to corruption of data that may be stored
there.
Move bootmem's allocation map to a location that does not cross any
reserved regions

Signed-off-by: Marcin Nowakowski 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14609/
Signed-off-by: Ralf Baechle 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

MIPS: Reserve nosave data for hibernation

2016-06-08T01:14:31+00:00

commit a95d069204e178f18476f5499abab0d0d9cbc32c upstream.

After commit 92923ca3aacef63c92d ("mm: meminit: only set page reserved
in the memblock region"), the MIPS hibernation is broken. Because pages
in nosave data section should be "reserved", but currently they aren't
set to "reserved" at initialization. This patch makes hibernation work
again.

Signed-off-by: Huacai Chen 
Cc: Aurelien Jarno 
Cc: Steven J . Hill 
Cc: Fuxin Zhang 
Cc: Zhangjin Wu 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12888/
Signed-off-by: Ralf Baechle 
Signed-off-by: Greg Kroah-Hartman

MIPS: vmlinux: create a section for appended DTB

2015-11-12T10:35:48+00:00

For bootloaders that support booting only ELF kernels and load only ELF
segments to memory there is no easy way to supply DTB without kernel
recompilation. For that purpose, create a section called .appended_dtb
that can be later updated with board-specific DTB using binutils e.g. at
kernel installation time.

Signed-off-by: Aaro Koskinen 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11114/
Signed-off-by: Ralf Baechle

MIPS: Make the kernel arguments from dtb available

2015-11-11T07:38:34+00:00

Similar to how arm allows using selecting between bootloader arguments,
dtb arguments and both, allow to select them on mips. But since we have
less control over the place of the dtb do not modify it but instead use
the boot_command_line for merging them.

The default is "use bootloader arguments" to keep the current behaviour
as default.

Signed-off-by: Jonas Gorski 
Cc: linux-mips@linux-mips.org
Cc: Kevin Cernekee 
Cc: Florian Fainelli 
Cc: Zubair Lutfullah Kakakhel 
Cc: James Hogan 
Cc: John Crispin 
Cc: Ganesan Ramalingam 
Cc: Jayachandran C 
Cc: Andrew Bresticker 
Cc: James Hartley 
Patchwork: https://patchwork.linux-mips.org/patch/11284/
Signed-off-by: Ralf Baechle

MIPS: Declare mips_debugfs_dir in a header

2015-10-26T08:49:42+00:00

We have many extern declarations of mips_debugfs_dir through arch/mips/
in various C files. Unify them by declaring mips_debugfs_dir in a
header, including it in each affected C file & removing the duplicate
declarations.

Signed-off-by: Paul Burton 
Cc: linux-mips@linux-mips.org
Cc: Steven J. Hill 
Cc: Alexander Sverdlin 
Cc: Masahiro Yamada 
Cc: Leonid Yegoshin 
Cc: Maciej W. Rozycki 
Cc: linux-kernel@vger.kernel.org
Cc: Joe Perches 
Cc: Jaedon Shin 
Cc: James Hogan 
Cc: David Daney 
Cc: Zubair Lutfullah Kakakhel 
Cc: Markos Chandras 
Cc: James Cowgill 
Patchwork: https://patchwork.linux-mips.org/patch/11181/
Signed-off-by: Ralf Baechle

MIPS: bootmem: Fix mapstart calculation for contiguous maps

2015-09-22T15:25:33+00:00

Commit a6335fa1 fixed the case with gap between initrd and next usable PFN zone,
but broken the case when initrd is combined with usable memory into one region
(in add_memory_region()). Restore the fixup initially brought in by f9a7febd.

---- error message ----
Unpacking initramfs...
Initramfs unpacking failed: junk in compressed archive
BUG: Bad page state in process swapper  pfn:00261
page:81004c20 count:0 mapcount:-127 mapping:  (null) index:0x2
flags: 0x0()
page dumped because: nonzero mapcount
CPU: 0 PID: 1 Comm: swapper Not tainted 4.2.0+ #1782
-----------------------

Signed-off-by: Alexander Sverdlin 
Reported-by: Tony Wu 
Tested-by: Tony Wu 
Cc: David Daney 
Cc: Zubair Lutfullah Kakakhel 
Cc: Huacai Chen 
Cc: Joe Perches 
Cc: Steven J. Hill 
Cc: Aaro Koskinen 
Cc: stable@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11086/
Signed-off-by: Ralf Baechle