linux.git/arch/mips/kernel/vmlinux.lds.S, branch v6.12.80

MIPS: Define RUNTIME_DISCARD_EXIT in LD script

2023-04-21T21:59:43+00:00

MIPS's exit sections are discarded at runtime as well.

Fixes link error:
`.exit.text' referenced in section `__jump_table' of fs/fuse/inode.o:
defined in discarded section `.exit.text' of fs/fuse/inode.o

Fixes: 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv")
Reported-by: "kernelci.org bot" 
Signed-off-by: Jiaxun Yang 
Signed-off-by: Thomas Bogendoerfer

objtool/idle: Validate __cpuidle code as noinstr

2023-01-13T10:48:15+00:00

Idle code is very like entry code in that RCU isn't available. As
such, add a little validation.

Signed-off-by: Peter Zijlstra (Intel) 
Signed-off-by: Ingo Molnar 
Tested-by: Tony Lindgren 
Tested-by: Ulf Hansson 
Acked-by: Geert Uytterhoeven 
Acked-by: Rafael J. Wysocki 
Acked-by: Frederic Weisbecker 
Link: https://lore.kernel.org/r/20230112195540.373461409@infradead.org

MIPS: vmlinux.lds.S: Fix appended dtb not properly aligned

2021-03-16T21:53:08+00:00

Commit 6654111c893f ("MIPS: vmlinux.lds.S: align raw appended dtb to 8
bytes") changed the alignment from STRUCT_ALIGNMENT bytes to 8 bytes.

The commit's message makes it sound like it was actually done on
purpose, but this is not the case. The commit was written when raw
appended dtb were not aligned at all. The STRUCT_ALIGN() was added a few
days before, in commit 7a05293af39f ("MIPS: boot/compressed: Copy DTB to
aligned address"). The true purpose of the commit was not to align
specifically to 8 bytes, but to make sure that the generated vmlinux'
size was properly padded to the alignment required for DTBs.

While the switch to 8-byte alignment worked for vmlinux-appended dtb
blobs, it broke vmlinuz-appended dtb blobs, as the decompress routine
moves the blob to a STRUCT_ALIGNMENT aligned address.

Fix this by changing the raw appended dtb blob alignment from 8 bytes
back to STRUCT_ALIGNMENT bytes in vmlinux.lds.S.

Fixes: 6654111c893f ("MIPS: vmlinux.lds.S: align raw appended dtb to 8 bytes")
Cc: Bjørn Mork 
Signed-off-by: Paul Cercueil 
Signed-off-by: Thomas Bogendoerfer

MIPS: vmlinux.lds.S: align raw appended dtb to 8 bytes

2021-03-08T17:36:08+00:00

The devicetree specification requires 8-byte alignment in
memory. This is now enforced by libfdt since commit 79edff12060f
("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9")
which included the upstream commit 5e735860c478 ("libfdt: Check for
8-byte address alignment in fdt_ro_probe_()").

This broke the MIPS raw appended DTBs which would be appended to
the image immediately following the initramfs section.  This ends
with a 32bit size, resulting in a 4-byte alignment of the DTB.

Fix by padding with zeroes to 8-bytes when MIPS_RAW_APPENDED_DTB
is defined.

Fixes: 79edff12060f ("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9")
Cc: Rob Herring 
Cc: Frank Rowand 
Signed-off-by: Bjørn Mork 
Signed-off-by: Thomas Bogendoerfer

MIPS: boot/compressed: Copy DTB to aligned address

2021-03-08T10:49:47+00:00

Since 5.12-rc1, the Device Tree blob must now be properly aligned.

Therefore, the decompress routine must be careful to copy the blob at
the next aligned address after the kernel image.

This commit fixes the kernel sometimes not booting with a Device Tree
blob appended to it.

Fixes: 79edff12060f ("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9")
Signed-off-by: Paul Cercueil 
Acked-by: Rob Herring 
Signed-off-by: Thomas Bogendoerfer

MIPS: vmlinux.lds.S: explicitly declare .got table

2021-01-15T14:27:54+00:00

LLVM stack generates GOT table when building the kernel:

ld.lld: warning: :(.got) is being placed in '.got'

According to the debug assertions, it's not zero-sized and thus can't
be handled the way it's done for x86.
Also use the ARM64 path here and place it at the end of .text section.

Reported-by: Nathan Chancellor 
Signed-off-by: Alexander Lobakin 
Reviewed-by: Kees Cook 
Reviewed-by: Nathan Chancellor 
Signed-off-by: Thomas Bogendoerfer

MIPS: vmlinux.lds.S: explicitly catch .rel.dyn symbols

2021-01-15T14:27:54+00:00

According to linker warnings, both GCC and LLVM generate '.rel.dyn'
symbols:

mips-alpine-linux-musl-ld: warning: orphan section `.rel.dyn'
from `init/main.o' being placed in section `.rel.dyn'

Link-time assertion shows that this section is sometimes empty,
sometimes not, depending on machine bitness and the compiler [0]:

  LD      .tmp_vmlinux.kallsyms1
mips64-linux-gnu-ld: Unexpected run-time relocations (.rel) detected!

Just use the ARM64 approach and declare it in vmlinux.lds.S closer
to __init_end.

[0] https://lore.kernel.org/linux-mips/20210109111259.GA4213@alpha.franken.de

Reported-by: Thomas Bogendoerfer 
Signed-off-by: Alexander Lobakin 
Reviewed-by: Nathan Chancellor 
Signed-off-by: Thomas Bogendoerfer

MIPS: properly stop .eh_frame generation

2021-01-15T14:27:54+00:00

Commit 866b6a89c6d1 ("MIPS: Add DWARF unwinding to assembly") added
-fno-asynchronous-unwind-tables to KBUILD_CFLAGS to prevent compiler
from emitting .eh_frame symbols.
However, as MIPS heavily uses CFI, that's not enough. Use the
approach taken for x86 (as it also uses CFI) and explicitly put CFI
symbols into the .debug_frame section (except for VDSO).
This allows us to drop .eh_frame from DISCARDS as it's no longer
being generated.

Fixes: 866b6a89c6d1 ("MIPS: Add DWARF unwinding to assembly")
Suggested-by: Kees Cook 
Signed-off-by: Alexander Lobakin 
Reviewed-by: Kees Cook 
Reviewed-by: Nathan Chancellor 
Signed-off-by: Thomas Bogendoerfer

MIPS: vmlinux.lds.S: add ".gnu.attributes" to DISCARDS

2021-01-15T14:27:54+00:00

Discard GNU attributes (MIPS FP type, GNU Hash etc.) at link time
as kernel doesn't use it at all.
Solves a dozen of the following ld warnings (one per every file):

mips-alpine-linux-musl-ld: warning: orphan section `.gnu.attributes'
from `arch/mips/kernel/head.o' being placed in section
`.gnu.attributes'
mips-alpine-linux-musl-ld: warning: orphan section `.gnu.attributes'
from `init/main.o' being placed in section `.gnu.attributes'

Signed-off-by: Alexander Lobakin 
Reviewed-by: Nathan Chancellor 
Signed-off-by: Thomas Bogendoerfer

MIPS: CPS: don't create redundant .text.cps-vec section

2021-01-15T14:27:54+00:00

A number of symbols from arch/mips/kernel/cps-vec.S is explicitly
placed into '.text.cps-vec' section.
There are no direct references to this section, so there's no need
to form it. '.balign 0x1000' directive will work anyway.

Moreover, this section was being placed in vmlinux differently
depending on CONFIG_LD_DEAD_CODE_DATA_ELIMINATION:
 - with this option enabled, '.text.cps-vec' was being caught
   by '.text.[0-9a-zA-Z_]*' from include/asm-generic/vmlinux.lds.h;
 - without this option, '.text.cps-vec' was being caught
   by discouraging '.text.*' from arch/mips/kernel/vmlinux.lds.S.

'.text.*' should not be used in vmlinux linker scripts at all as it
silently catches any orphan text sections.
So, remove both '.section .text.cps-vec' and '.text.*' from cps-vec.S
and vmlinux.lds.S respectively. As said, this does not affect related
functions alignment:

80116000 T mips_cps_core_entry
80116028 t not_nmi
80116200 T excep_tlbfill
80116280 T excep_xtlbfill
80116300 T excep_cache
80116380 T excep_genex
80116400 T excep_intex
80116480 T excep_ejtag
80116490 T mips_cps_core_init

Signed-off-by: Alexander Lobakin 
Signed-off-by: Thomas Bogendoerfer