linux/arch
Palmer Dabbelt 71e11d066c
Merge patch series "riscv: kexec: cleanup and fixups"
Song Shuai <songshuaishuai@tinylab.org> says:

This series contains a cleanup for riscv_kexec_relocate() and two fixups
for KEXEC_FILE and had passed the basic kexec test in my 64bit Qemu-virt.

You can use this kexec-tools[3] to test the kexec-file-syscall and these patches.

riscv: kexec: Cleanup riscv_kexec_relocate (patch1)
==================================================

For readability and simplicity, cleanup the riscv_kexec_relocate code:

 - Re-sort the first 4 `mv` instructions against `riscv_kexec_method()`
 - Eliminate registers for debugging (s9,s10,s11) and storing const-value (s5,s6)
 - Replace `jalr` with `jr` for no-link jump

riscv: kexec: Align the kexeced kernel entry (patch2)
==================================================

The current riscv boot protocol requires 2MB alignment for RV64
and 4MB alignment for RV32.

In KEXEC_FILE path, the elf_find_pbase() function should align
the kexeced kernel entry according to the requirement, otherwise
the kexeced kernel would silently BUG at the setup_vm().

riscv: kexec: Remove -fPIE for PURGATORY_CFLAGS (patch3)
==================================================

With CONFIG_RELOCATABLE enabled, KBUILD_CFLAGS had a -fPIE option
and then the purgatory/string.o was built to reference _ctype symbol
via R_RISCV_GOT_HI20 relocations which can't be handled by purgatory.

As a consequence, the kernel failed kexec_load_file() with:

[  880.386562] kexec_image: The entry point of kernel at 0x80200000
[  880.388650] kexec_image: Unknown rela relocation: 20
[  880.389173] kexec_image: Error loading purgatory ret=-8

So remove the -fPIE option for PURGATORY_CFLAGS to generate
R_RISCV_PCREL_HI20 relocations type making puragtory work as it was.

 arch/riscv/kernel/elf_kexec.c      |  8 ++++-
 arch/riscv/kernel/kexec_relocate.S | 52 +++++++++++++-----------------
 arch/riscv/purgatory/Makefile      |  4 +++
 3 files changed, 34 insertions(+), 30 deletions(-)

* b4-shazam-merge:
  riscv: kexec: Remove -fPIE for PURGATORY_CFLAGS
  riscv: kexec: Align the kexeced kernel entry
  riscv: kexec: Cleanup riscv_kexec_relocate

Link: https://lore.kernel.org/r/20230907103304.590739-1-songshuaishuai@tinylab.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-10-31 19:15:41 -07:00
..
alpha Kbuild updates for v6.6 2023-09-05 11:01:47 -07:00
arc ARC updates for v6.6 2023-09-04 15:38:24 -07:00
arm ARM: 2023-09-07 13:52:20 -07:00
arm64 RISC-V Patches for the 6.6 Merge Window, Part 2 (try 2) 2023-09-09 14:25:11 -07:00
csky arch/csky 2nd patches for 6.6 2023-09-01 08:02:45 -07:00
hexagon Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
ia64 Kbuild updates for v6.6 2023-09-05 11:01:47 -07:00
loongarch LoongArch changes for v6.6 2023-09-08 12:16:52 -07:00
m68k ata changes for 6.6 2023-09-05 12:37:28 -07:00
microblaze Microblaze patches for 6.6-rc1 2023-09-05 10:15:22 -07:00
mips ARM: 2023-09-07 13:52:20 -07:00
nios2 Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
openrisc OpenRISC updates for 6.6 2023-09-05 10:09:31 -07:00
parisc ata changes for 6.6 2023-09-05 12:37:28 -07:00
powerpc ata changes for 6.6 2023-09-05 12:37:28 -07:00
riscv Merge patch series "riscv: kexec: cleanup and fixups" 2023-10-31 19:15:41 -07:00
s390 Including fixes from netfilter and bpf. 2023-09-07 18:33:07 -07:00
sh sh updates for v6.6 2023-09-09 14:46:57 -07:00
sparc ata changes for 6.6 2023-09-05 12:37:28 -07:00
um This pull request contains the following changes for UML: 2023-09-04 11:32:21 -07:00
x86 Fix preemption delays in the SGX code, remove unnecessarily UAPI-exported code, 2023-09-10 10:39:31 -07:00
xtensa Xtensa updates for v6.6 2023-09-07 10:30:17 -07:00
.gitignore
Kconfig Add x86 shadow stack support 2023-08-31 12:20:12 -07:00