From 1c811a4d1db56e4ed4fefa99ea39c679aa0c29f0 Mon Sep 17 00:00:00 2001 From: Thomas Preud'homme Date: Sat, 12 Nov 2016 23:16:07 +0800 Subject: Make build_got_entries more target independent Factor most of common logic between targets in build_got_entries by defining target specific info into structures in the backends. --- arm-link.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 52 insertions(+), 2 deletions(-) (limited to 'arm-link.c') diff --git a/arm-link.c b/arm-link.c index 00332e0..ec989bb 100644 --- a/arm-link.c +++ b/arm-link.c @@ -1,6 +1,30 @@ #include "tcc.h" #define HAVE_SECTION_RELOC +ST_DATA struct reloc_info relocs_info[] = { + INIT_RELOC_INFO (R_ARM_PC24, 1, AUTO_GOTPLT_ENTRY, 0) + INIT_RELOC_INFO (R_ARM_CALL, 1, AUTO_GOTPLT_ENTRY, 0) + INIT_RELOC_INFO (R_ARM_JUMP24, 1, AUTO_GOTPLT_ENTRY, 0) + INIT_RELOC_INFO (R_ARM_PLT32, 1, ALWAYS_GOTPLT_ENTRY, 0) + INIT_RELOC_INFO (R_ARM_THM_PC22, 1, AUTO_GOTPLT_ENTRY, 0) + INIT_RELOC_INFO (R_ARM_THM_JUMP24, 1, AUTO_GOTPLT_ENTRY, 0) + INIT_RELOC_INFO (R_ARM_MOVT_ABS, 0, AUTO_GOTPLT_ENTRY, 0) + INIT_RELOC_INFO (R_ARM_MOVW_ABS_NC, 0, AUTO_GOTPLT_ENTRY, 0) + INIT_RELOC_INFO (R_ARM_THM_MOVT_ABS, 0, AUTO_GOTPLT_ENTRY, 0) + INIT_RELOC_INFO (R_ARM_THM_MOVW_ABS_NC, 0, AUTO_GOTPLT_ENTRY, 0) + INIT_RELOC_INFO (R_ARM_PREL31, 1, AUTO_GOTPLT_ENTRY, 0) + INIT_RELOC_INFO (R_ARM_ABS32, 0, NO_GOTPLT_ENTRY, 0) + INIT_RELOC_INFO (R_ARM_REL32, 0, AUTO_GOTPLT_ENTRY, 0) + INIT_RELOC_INFO (R_ARM_GOTPC, 0, BUILD_GOT_ONLY, 0) + INIT_RELOC_INFO (R_ARM_GOTOFF, 0, BUILD_GOT_ONLY, 0) + INIT_RELOC_INFO (R_ARM_GOT32, 0, ALWAYS_GOTPLT_ENTRY, 0) + INIT_RELOC_INFO (R_ARM_COPY, 0, NO_GOTPLT_ENTRY, 0) + INIT_RELOC_INFO (R_ARM_V4BX, 1, AUTO_GOTPLT_ENTRY, 0) + INIT_RELOC_INFO (R_ARM_GLOB_DAT, 0, NO_GOTPLT_ENTRY, 0) + INIT_RELOC_INFO (R_ARM_JUMP_SLOT, 1, NO_GOTPLT_ENTRY, 0) + INIT_RELOC_INFO (R_ARM_NONE, 0, NO_GOTPLT_ENTRY, 0) +}; + void relocate_init(Section *sr) {} void relocate(TCCState *s1, ElfW_Rel *rel, int type, char *ptr, addr_t addr, addr_t val) @@ -19,8 +43,7 @@ void relocate(TCCState *s1, ElfW_Rel *rel, int type, char *ptr, addr_t addr, add { int x, is_thumb, is_call, h, blx_avail, is_bl, th_ko; x = (*(int *) ptr) & 0xffffff; - if (sym->st_shndx == SHN_UNDEF || - s1->output_type == TCC_OUTPUT_MEMORY) + if (sym->st_shndx == SHN_UNDEF || sym->st_shndx == SHN_ABS) val = s1->plt->sh_addr; #ifdef DEBUG_RELOC printf ("reloc %d: x=0x%x val=0x%x ", type, x, val); @@ -89,6 +112,33 @@ void relocate(TCCState *s1, ElfW_Rel *rel, int type, char *ptr, addr_t addr, add (val < plt->sh_addr + plt->data_offset); is_call = (type == R_ARM_THM_PC22); + if (!to_thumb && !to_plt && !is_call) { + int index; + uint8_t *p; + char *name, buf[1024]; + Section *text_section; + + name = (char *) symtab_section->link->data + sym->st_name; + text_section = s1->sections[sym->st_shndx]; + /* Modify reloc to target a thumb stub to switch to ARM */ + snprintf(buf, sizeof(buf), "%s_from_thumb", name); + index = put_elf_sym(symtab_section, + text_section->data_offset + 1, + sym->st_size, sym->st_info, 0, + sym->st_shndx, buf); + to_thumb = 1; + val = text_section->data_offset + 1; + rel->r_info = ELFW(R_INFO)(index, type); + /* Create a thumb stub function to switch to ARM mode */ + put_elf_reloc(symtab_section, text_section, + text_section->data_offset + 4, R_ARM_JUMP24, + sym_index); + p = section_ptr_add(text_section, 8); + write32le(p, 0x4778); /* bx pc */ + write32le(p+2, 0x46c0); /* nop */ + write32le(p+4, 0xeafffffe); /* b $sym */ + } + /* Compute final offset */ if (to_plt && !is_call) /* Point to 1st instr of Thumb stub */ x -= 4; -- cgit v1.3.1