linux-toradex.git/arch/mips/kernel/vmlinux.lds.S, branch v4.4.106

MIPS: Ensure bss section ends on a long-aligned address

2017-10-08T08:14:16+00:00

[ Upstream commit 3f00f4d8f083bc61005d0a1ef592b149f5c88bbd ]

When clearing the .bss section in kernel_entry we do so using LONG_S
instructions, and branch whilst the current write address doesn't equal
the end of the .bss section minus the size of a long integer. The .bss
section always begins at a long-aligned address and we always increment
the write pointer by the size of a long integer - we therefore rely upon
the .bss section ending at a long-aligned address. If this is not the
case then the long-aligned write address can never be equal to the
non-long-aligned end address & we will continue to increment past the
end of the .bss section, attempting to zero the rest of memory.

Despite this requirement that .bss end at a long-aligned address we pass
0 as the end alignment requirement to the BSS_SECTION macro and thus
don't guarantee any particular alignment, allowing us to hit the error
condition described above.

Fix this by instead passing 8 bytes as the end alignment argument to
the BSS_SECTION macro, ensuring that the end of the .bss section is
always at least long-aligned.

Signed-off-by: Paul Burton 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14526/
Signed-off-by: Ralf Baechle 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Merge branch '4.3-fixes' into mips-for-linux-next

2015-11-12T10:36:03+00:00

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: OCTEON: omit ELF NOTE segments

2015-11-10T13:44:40+00:00

OCTEON Pre-SDK-1.8.1 bootloaders can not handle PT_NOTE program headers,
so do not emit them.

Before the patch:

$ readelf --program-headers octeon-vmlinux

Elf file type is EXEC (Executable file)
Entry point 0xffffffff815d09d0
There are 2 program headers, starting at offset 64

Program Headers:
  Type           Offset             VirtAddr           PhysAddr
                 FileSiz            MemSiz              Flags  Align
  LOAD           0x0000000000001000 0xffffffff81100000 0xffffffff81100000
                 0x0000000000b57f80 0x0000000001b86360  RWE    1000
  NOTE           0x00000000004e02e0 0xffffffff815df2e0 0xffffffff815df2e0
                 0x0000000000000024 0x0000000000000024  R      4

After the patch:

$ readelf --program-headers octeon-vmlinux

Elf file type is EXEC (Executable file)
Entry point 0xffffffff815d09d0
There are 1 program headers, starting at offset 64

Program Headers:
  Type           Offset             VirtAddr           PhysAddr
                 FileSiz            MemSiz              Flags  Align
  LOAD           0x0000000000001000 0xffffffff81100000 0xffffffff81100000
                 0x0000000000b57f80 0x0000000001b86360  RWE    1000

The patch was tested on DSR-1000N router.

Signed-off-by: David Daney 
Signed-off-by: Aaro Koskinen 
Cc: Matthew Fortune 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11403/
Signed-off-by: Ralf Baechle

MIPS: vmlinux: discard .MIPS.abiflags

2015-11-10T13:44:37+00:00

Discard .MIPS.abiflags from vmlinux. It's not needed and will cause
issues e.g. with old OCTEON bootloaders that cannot tolerate
additional program headers.

Before the patch:

$ readelf --program-headers octeon-vmlinux

Elf file type is EXEC (Executable file)
Entry point 0xffffffff815d09d0
There are 3 program headers, starting at offset 64

Program Headers:
  Type           Offset             VirtAddr           PhysAddr
                 FileSiz            MemSiz              Flags  Align
  ABIFLAGS       0x00000000005e77f0 0xffffffff816e67f0 0xffffffff816e67f0
                 0x0000000000000018 0x0000000000000018  R      8
  LOAD           0x0000000000001000 0xffffffff81100000 0xffffffff81100000
                 0x0000000000b57f80 0x0000000001b86360  RWE    1000
  NOTE           0x00000000004e02e0 0xffffffff815df2e0 0xffffffff815df2e0
                 0x0000000000000024 0x0000000000000024  R      4

After the patch:

$ readelf --program-headers octeon-vmlinux

Elf file type is EXEC (Executable file)
Entry point 0xffffffff815d09d0
There are 2 program headers, starting at offset 64

Program Headers:
  Type           Offset             VirtAddr           PhysAddr
                 FileSiz            MemSiz              Flags  Align
  LOAD           0x0000000000001000 0xffffffff81100000 0xffffffff81100000
                 0x0000000000b57f80 0x0000000001b86360  RWE    1000
  NOTE           0x00000000004e02e0 0xffffffff815df2e0 0xffffffff815df2e0
                 0x0000000000000024 0x0000000000000024  R      4

Suggested-by: Matthew Fortune 
Suggested-by: Ralf Baechle 
Signed-off-by: Aaro Koskinen 
Cc: linux-mips@linux-mips.org
Cc: David Daney 
Patchwork: https://patchwork.linux-mips.org/patch/11402/
Signed-off-by: Ralf Baechle

MIPS: Add support for vmlinux.bin appended dtb

2015-06-21T19:54:14+00:00

Add support for detecting a vmlinux.bin appended dtb and overriding
the boot arguments to match the UHI interface.

Due to the PERCPU section being empty for !SMP, but still modifying
the current address by aligning it to the page size, do not define
it for !SMP builds to allow __appended_dtb to still point to
the actual end of the data.

Signed-off-by: Jonas Gorski 
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: John Crispin 
Cc: Kevin Cernekee 
Cc: Florian Fainelli 
Cc: Aaro Koskinen 
Cc: Markos Chandras 
Cc: Andrew Bresticker 
Cc: Daniel Schwierzeck 
Cc: Paul Burton 
Cc: James Hartley 
Patchwork: https://patchwork.linux-mips.org/patch/9739/
Signed-off-by: Ralf Baechle

MIPS: Discard .eh_frame sections in linker script.

2013-08-26T13:33:41+00:00

Some toolchains (including Cavium OCTEON SDK) are emitting .eh_frame
sections by default.  Discard them as they are useless in the kernel.

Signed-off-by: David Daney 
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/5684/
Signed-off-by: Ralf Baechle

MIPS: Whitespace cleanup.

2013-02-01T09:00:22+00:00

Having received another series of whitespace patches I decided to do this
once and for all rather than dealing with this kind of patches trickling
in forever.

Signed-off-by: Ralf Baechle

MIPS: Switch remaining assembler PAGE_SIZE users to .

2012-12-28T16:04:16+00:00

Signed-off-by: Ralf Baechle

MIPS: Align swapper_pg_dir to 64K for better TLB Refill code.

2012-10-11T09:02:40+00:00

We can save an instruction in the TLB Refill path for kernel mappings
by aligning swapper_pg_dir on a 64K boundary.  The address of
swapper_pg_dir can be generated with a single LUI instead of
LUI/{D}ADDUI.

The alignment of __init_end is bumped up to 64K so there are no holes
between it and swapper_pg_dir, which is placed at the very beginning
of .bss.

The alignment of invalid_pmd_table and invalid_pte_table can be
relaxed to PAGE_SIZE.  We do this by using __page_aligned_bss, which
has the added benefit of eliminating alignment holes in .bss.

Signed-off-by: David Daney 
Cc: linux-mips@linux-mips.org
Cc: linux-arch@vger.kernel.org,
Cc: linux-kernel@vger.kernel.org
Acked-by: Arnd Bergmann 
Patchwork: https://patchwork.linux-mips.org/patch/4220/
Signed-off-by: Ralf Baechle