From ff807a20bd9a2b4b7e86cb49c466cac0a298b64e Mon Sep 17 00:00:00 2001 From: Andrew Waterman Date: Sun, 13 Nov 2016 16:40:58 -0800 Subject: Fix ld.so load address at 4 KiB --- pk/elf.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'pk') diff --git a/pk/elf.c b/pk/elf.c index 1da29b2..5db3680 100644 --- a/pk/elf.c +++ b/pk/elf.c @@ -46,7 +46,6 @@ void load_elf(const char* fn, elf_info* info) assert(!(eh.e_flags & EF_RISCV_RVC)); #endif - uintptr_t min_vaddr = -1; size_t phdr_size = eh.e_phnum * sizeof(Elf_Phdr); if (phdr_size > info->phdr_size) goto fail; @@ -56,14 +55,19 @@ void load_elf(const char* fn, elf_info* info) info->phnum = eh.e_phnum; info->phent = sizeof(Elf_Phdr); Elf_Phdr* ph = (typeof(ph))info->phdr; + + // compute highest VA in ELF + uintptr_t max_vaddr = 0; for (int i = 0; i < eh.e_phnum; i++) - if (ph[i].p_type == PT_LOAD && ph[i].p_memsz && ph[i].p_vaddr < min_vaddr) - min_vaddr = ph[i].p_vaddr; - min_vaddr = ROUNDDOWN(min_vaddr, RISCV_PGSIZE); + if (ph[i].p_type == PT_LOAD && ph[i].p_memsz) + max_vaddr = MAX(max_vaddr, ph[i].p_vaddr + ph[i].p_memsz); + max_vaddr = ROUNDUP(max_vaddr, RISCV_PGSIZE); + + // don't load dynamic linker at 0, else we can't catch NULL pointer derefs uintptr_t bias = 0; if (eh.e_type == ET_DYN) - bias = first_free_paddr - min_vaddr; - min_vaddr += bias; + bias = RISCV_PGSIZE; + info->entry = eh.e_entry + bias; int flags = MAP_FIXED | MAP_PRIVATE; for (int i = eh.e_phnum - 1; i >= 0; i--) { -- cgit v1.1