mips compat: switch to compat_binfmt_elf.c

2021-01-06T13:42:49Z

Like amd64, mips has two 32bit ABIs - o32 and n32. Unlike amd64, it does not use compat_binfmt_elf.c for either of those; each of those ABIs has a binfmt handler of its own, both very similar to fs/compat_binfmt_elf.c. And the same technics as we use on amd64 can be used to make fs/compat_binfmt_elf.c handle both. * merge elfo32_check_arch() with elfn32_check_arch(), make that serve as compat_elf_check_arch(). Note that SET_PERSONALITY2() is already the same for all ABI variants - it looks at the elf header to choose the flags to set. * add asm/elfcore-compat.h, using the bigger (n32) variant of elf32_prstatus as compat_elf_prstatus there. * make PRSTATUS_SIZE() and SET_PR_FPVALID() choose the right layout, same as done for amd64. test_thread_flag(TIF_32BIT_REGS) is used as the predicate. Voila - we are rid of binfmt_elf{n,o}32.c; fs/compat_binfmt_elf.c is used, same as for all other ELF-supporting 64bit architectures that need 32bit compat. Signed-off-by: Al Viro

kernel/arch/mips/include/asm/elfcore-compat.h, branch linux-6.2.y

mips compat: switch to compat_binfmt_elf.c