Upstream-Status: Backport From 26e802720ccd055d70addadbc39f4119716f8573 Mon Sep 17 00:00:00 2001 From: cltang Date: Mon, 19 Dec 2011 10:39:27 +0000 Subject: [PATCH 036/262] 2011-12-19 Chung-Lin Tang Backport from mainline: 2011-12-19 Chung-Lin Tang Catherine Moore Sandra Loosemore Richard Sandiford * elfxx-mips.c (mips_elf_local_pic_function_p): Return true when H is a MIPS16 function with a kept 32-bit stub. Update comments. (mips_elf_get_la25_target): New function. (mips_elf_add_la25_intro): Change to use mips_elf_get_la25_target(). (mips_elf_add_la25_stub): Move compute of use_trampoline_p down, change to use mips_elf_get_la25_target(). (mips_elf_relocation_needs_la25_stub): Add target_is_16_bit_code_p parameter, add switch case for R_MIPS16_26. (mips_elf_calculate_relocation): Redirect relocation to point to the LA25 stub if it exists, instead of the MIPS16 stub. Update arguments of call to mips_elf_relocation_needs_la25_stub(), don't use la25 stub for mips16->mips16 calls. (_bfd_mips_elf_check_relocs): Update arguments of call to mips_elf_relocation_needs_la25_stub(). (mips_elf_create_la25_stub): Change to use mips_elf_get_la25_target(). diff --git a/bfd/elfxx-mips.c b/bfd/elfxx-mips.c index 3939183..9f3833b 100644 --- a/bfd/elfxx-mips.c +++ b/bfd/elfxx-mips.c @@ -1575,9 +1575,10 @@ _bfd_mips_elf_init_stubs (struct bfd_link_info *info, } /* Return true if H is a locally-defined PIC function, in the sense - that it might need $25 to be valid on entry. Note that MIPS16 - functions never need $25 to be valid on entry; they set up $gp - using PC-relative instructions instead. */ + that it or its fn_stub might need $25 to be valid on entry. + Note that MIPS16 functions set up $gp using PC-relative instructions, + so they themselves never need $25 to be valid. Only non-MIPS16 + entry points are of interest here. */ static bfd_boolean mips_elf_local_pic_function_p (struct mips_elf_link_hash_entry *h) @@ -1586,11 +1587,32 @@ mips_elf_local_pic_function_p (struct mips_elf_link_hash_entry *h) || h->root.root.type == bfd_link_hash_defweak) && h->root.def_regular && !bfd_is_abs_section (h->root.root.u.def.section) - && !ELF_ST_IS_MIPS16 (h->root.other) + && (!ELF_ST_IS_MIPS16 (h->root.other) + || (h->fn_stub && h->need_fn_stub)) && (PIC_OBJECT_P (h->root.root.u.def.section->owner) || ELF_ST_IS_MIPS_PIC (h->root.other))); } +/* Set *SEC to the input section that contains the target of STUB. + Return the offset of the target from the start of that section. */ + +static bfd_vma +mips_elf_get_la25_target (struct mips_elf_la25_stub *stub, + asection **sec) +{ + if (ELF_ST_IS_MIPS16 (stub->h->root.other)) + { + BFD_ASSERT (stub->h->need_fn_stub); + *sec = stub->h->fn_stub; + return 0; + } + else + { + *sec = stub->h->root.root.u.def.section; + return stub->h->root.root.u.def.value; + } +} + /* STUB describes an la25 stub that we have decided to implement by inserting an LUI/ADDIU pair before the target function. Create the section and redirect the function symbol to it. */ @@ -1615,7 +1637,7 @@ mips_elf_add_la25_intro (struct mips_elf_la25_stub *stub, sprintf (name, ".text.stub.%d", (int) htab_elements (htab->la25_stubs)); /* Create the section. */ - input_section = stub->h->root.root.u.def.section; + mips_elf_get_la25_target (stub, &input_section); s = htab->add_stub_section (name, input_section, input_section->output_section); if (s == NULL) @@ -1689,12 +1711,6 @@ mips_elf_add_la25_stub (struct bfd_link_info *info, bfd_vma value; void **slot; - /* Prefer to use LUI/ADDIU stubs if the function is at the beginning - of the section and if we would need no more than 2 nops. */ - s = h->root.root.u.def.section; - value = h->root.root.u.def.value; - use_trampoline_p = (value != 0 || s->alignment_power > 4); - /* Describe the stub we want. */ search.stub_section = NULL; search.offset = 0; @@ -1724,6 +1740,11 @@ mips_elf_add_la25_stub (struct bfd_link_info *info, *stub = search; *slot = stub; + /* Prefer to use LUI/ADDIU stubs if the function is at the beginning + of the section and if we would need no more than 2 nops. */ + value = mips_elf_get_la25_target (stub, &s); + use_trampoline_p = (value != 0 || s->alignment_power > 4); + h->la25_stub = stub; return (use_trampoline_p ? mips_elf_add_la25_trampoline (stub, info) @@ -4911,7 +4932,8 @@ is_gott_symbol (struct bfd_link_info *info, struct elf_link_hash_entry *h) stub. */ static bfd_boolean -mips_elf_relocation_needs_la25_stub (bfd *input_bfd, int r_type) +mips_elf_relocation_needs_la25_stub (bfd *input_bfd, int r_type, + bfd_boolean target_is_16_bit_code_p) { /* We specifically ignore branches and jumps from EF_PIC objects, where the onus is on the compiler or programmer to perform any @@ -4925,7 +4947,6 @@ mips_elf_relocation_needs_la25_stub (bfd *input_bfd, int r_type) { case R_MIPS_26: case R_MIPS_PC16: - case R_MIPS16_26: case R_MICROMIPS_26_S1: case R_MICROMIPS_PC7_S1: case R_MICROMIPS_PC10_S1: @@ -4933,6 +4954,9 @@ mips_elf_relocation_needs_la25_stub (bfd *input_bfd, int r_type) case R_MICROMIPS_PC23_S2: return TRUE; + case R_MIPS16_26: + return !target_is_16_bit_code_p; + default: return FALSE; } @@ -5193,14 +5217,28 @@ mips_elf_calculate_relocation (bfd *abfd, bfd *input_bfd, have already noticed that we were going to need the stub. */ if (local_p) - sec = elf_tdata (input_bfd)->local_stubs[r_symndx]; + { + sec = elf_tdata (input_bfd)->local_stubs[r_symndx]; + value = 0; + } else { BFD_ASSERT (h->need_fn_stub); - sec = h->fn_stub; + if (h->la25_stub) + { + /* If a LA25 header for the stub itself exists, point to the + prepended LUI/ADDIU sequence. */ + sec = h->la25_stub->stub_section; + value = h->la25_stub->offset; + } + else + { + sec = h->fn_stub; + value = 0; + } } - symbol = sec->output_section->vma + sec->output_offset; + symbol = sec->output_section->vma + sec->output_offset + value; /* The target is 16-bit, but the stub isn't. */ target_is_16_bit_code_p = FALSE; } @@ -5250,7 +5288,8 @@ mips_elf_calculate_relocation (bfd *abfd, bfd *input_bfd, /* If this is a direct call to a PIC function, redirect to the non-PIC stub. */ else if (h != NULL && h->la25_stub - && mips_elf_relocation_needs_la25_stub (input_bfd, r_type)) + && mips_elf_relocation_needs_la25_stub (input_bfd, r_type, + target_is_16_bit_code_p)) symbol = (h->la25_stub->stub_section->output_section->vma + h->la25_stub->stub_section->output_offset + h->la25_stub->offset); @@ -7925,7 +7964,9 @@ _bfd_mips_elf_check_relocs (bfd *abfd, struct bfd_link_info *info, return FALSE; } - if (h != NULL && mips_elf_relocation_needs_la25_stub (abfd, r_type)) + if (h != NULL + && mips_elf_relocation_needs_la25_stub (abfd, r_type, + ELF_ST_IS_MIPS16 (h->other))) ((struct mips_elf_link_hash_entry *) h)->has_nonpic_branches = TRUE; switch (r_type) @@ -9622,9 +9663,9 @@ mips_elf_create_la25_stub (void **slot, void *data) offset = stub->offset; /* Work out the target address. */ - target = (stub->h->root.root.u.def.section->output_section->vma - + stub->h->root.root.u.def.section->output_offset - + stub->h->root.root.u.def.value); + target = mips_elf_get_la25_target (stub, &s); + target += s->output_section->vma + s->output_offset; + target_high = ((target + 0x8000) >> 16) & 0xffff; target_low = (target & 0xffff); -- 1.7.9.5