From 463f06849999687ae5a93dcb4fa523bedeb78ef9 Mon Sep 17 00:00:00 2001 From: Hajime Tazaki Date: Sat, 14 Sep 2024 10:06:33 +0900 Subject: [PATCH] fs: binfmt_elf_efpic: add architecture hook elf_arch_finalize_exec FDPIC ELF loader adds an architecture hook at the end of loading binaries to finalize the mapped memory before moving toward exec function. The hook is used by UML under !MMU when translating syscall/sysenter instructions before calling execve. Cc: Alexander Viro Cc: Christian Brauner Cc: Jan Kara Cc: Eric Biederman Cc: Kees Cook Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Signed-off-by: Hajime Tazaki --- fs/binfmt_elf_fdpic.c | 10 ++++++++++ include/linux/elf-fdpic.h | 3 +++ 2 files changed, 13 insertions(+) diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index 4fe5bb9f1b1f5e..ab16fdf475b035 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -175,6 +175,12 @@ static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, return 0; } +int __weak elf_arch_finalize_exec(struct elf_fdpic_params *exec_params, + struct elf_fdpic_params *interp_params) +{ + return 0; +} + /*****************************************************************************/ /* * load an fdpic binary into various bits of memory @@ -457,6 +463,10 @@ static int load_elf_fdpic_binary(struct linux_binprm *bprm) dynaddr); #endif + retval = elf_arch_finalize_exec(&exec_params, &interp_params); + if (retval) + goto error; + finalize_exec(bprm); /* everything is now ready... get the userspace context ready to roll */ entryaddr = interp_params.entry_addr ?: exec_params.entry_addr; diff --git a/include/linux/elf-fdpic.h b/include/linux/elf-fdpic.h index e533f45131945f..e7fd85a1d10f6f 100644 --- a/include/linux/elf-fdpic.h +++ b/include/linux/elf-fdpic.h @@ -56,4 +56,7 @@ extern void elf_fdpic_arch_lay_out_mm(struct elf_fdpic_params *exec_params, unsigned long *start_brk); #endif +extern int elf_arch_finalize_exec(struct elf_fdpic_params *exec_params, + struct elf_fdpic_params *interp_params); + #endif /* _LINUX_ELF_FDPIC_H */