From 9e2a48988a4e469d5010bcd27c036ef9ee10a53e Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Tue, 18 Dec 2001 11:49:52 +0000 Subject: [PATCH] * elf-eh-frame.c (struct cie): Add make_lsda_relative. (struct eh_cie_fde): Add lsda_encoding, lsda_offset, make_lsda_relative. (read_value, write_value): New. (_bfd_elf_discard_section_eh_frame): Inicialize lsda_encoding, lsda_offset and make_lsda_relative. (_bfd_elf_eh_frame_section_offset): If make_lsda_relative, request no dynamic reloc for LSDA field of FDE. (_bfd_elf_write_section_eh_frame): Handle make_lsda_relative. If a non-DW_EH_PE_absptr value is 0, don't adjust it by base or pcrel. Fix address computation for DW_EH_PE_pcrel relocs. Update LSDA field if LSDA encoding is DW_EH_PE_pcrel, because . might have changed due to deleted FDE or CIEs. --- bfd/ChangeLog | 16 ++++ bfd/elf-eh-frame.c | 202 ++++++++++++++++++++++++++++++++++----------- 2 files changed, 172 insertions(+), 46 deletions(-) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 1ce252158e1..e760aa3f2b1 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,19 @@ +2001-12-18 Jakub Jelinek + + * elf-eh-frame.c (struct cie): Add make_lsda_relative. + (struct eh_cie_fde): Add lsda_encoding, lsda_offset, + make_lsda_relative. + (read_value, write_value): New. + (_bfd_elf_discard_section_eh_frame): Inicialize + lsda_encoding, lsda_offset and make_lsda_relative. + (_bfd_elf_eh_frame_section_offset): If make_lsda_relative, + request no dynamic reloc for LSDA field of FDE. + (_bfd_elf_write_section_eh_frame): Handle make_lsda_relative. + If a non-DW_EH_PE_absptr value is 0, don't adjust it by base + or pcrel. Fix address computation for DW_EH_PE_pcrel relocs. + Update LSDA field if LSDA encoding is DW_EH_PE_pcrel, because + . might have changed due to deleted FDE or CIEs. + 2001-12-18 Jakub Jelinek * elf-strtab.c (struct elf_strtab_hash_entry): Add u.next. diff --git a/bfd/elf-eh-frame.c b/bfd/elf-eh-frame.c index 14c690be3db..2436c17e37d 100644 --- a/bfd/elf-eh-frame.c +++ b/bfd/elf-eh-frame.c @@ -47,6 +47,7 @@ struct cie unsigned char fde_encoding; unsigned char initial_insn_length; unsigned char make_relative; + unsigned char make_lsda_relative; unsigned char initial_instructions[50]; }; @@ -57,9 +58,12 @@ struct eh_cie_fde asection *sec; unsigned int new_offset; unsigned char fde_encoding; + unsigned char lsda_encoding; + unsigned char lsda_offset; unsigned char cie : 1; unsigned char removed : 1; unsigned char make_relative : 1; + unsigned char make_lsda_relative : 1; }; struct eh_frame_sec_info @@ -95,6 +99,10 @@ static bfd_signed_vma read_signed_leb128 PARAMS ((bfd *, char *, unsigned int *)); static int get_DW_EH_PE_width PARAMS ((int, int)); +static bfd_vma read_value + PARAMS ((bfd *, bfd_byte *, int)); +static void write_value + PARAMS ((bfd *, bfd_byte *, bfd_vma, int)); static int cie_compare PARAMS ((struct cie *, struct cie *)); static int vma_compare @@ -200,6 +208,45 @@ int get_DW_EH_PE_width (encoding, ptr_size) return 0; } +/* Read a width sized value from memory. */ + +static bfd_vma +read_value (abfd, buf, width) + bfd *abfd; + bfd_byte *buf; + int width; +{ + bfd_vma value; + + switch (width) + { + case 2: value = bfd_get_16 (abfd, buf); break; + case 4: value = bfd_get_32 (abfd, buf); break; + case 8: value = bfd_get_64 (abfd, buf); break; + default: BFD_FAIL (); return 0; + } + + return value; +} + +/* Store a width sized value to memory. */ + +static void +write_value (abfd, buf, value, width) + bfd *abfd; + bfd_byte *buf; + bfd_vma value; + int width; +{ + switch (width) + { + case 2: bfd_put_16 (abfd, value, buf); break; + case 4: bfd_put_32 (abfd, value, buf); break; + case 8: bfd_put_64 (abfd, value, buf); break; + default: BFD_FAIL (); + } +} + /* Return zero if C1 and C2 CIEs can be merged. */ static @@ -249,7 +296,8 @@ _bfd_elf_discard_section_eh_frame (abfd, info, sec, ehdrsec, struct eh_frame_hdr_info *hdr_info; struct eh_frame_sec_info *sec_info = NULL; unsigned int leb128_tmp; - unsigned int cie_usage_count, last_cie_ndx, i, offset, make_relative; + unsigned int cie_usage_count, last_cie_ndx, i, offset; + unsigned int make_relative, make_lsda_relative; Elf_Internal_Rela *rel; bfd_size_type new_size; unsigned int ptr_size; @@ -306,6 +354,7 @@ _bfd_elf_discard_section_eh_frame (abfd, info, sec, ehdrsec, cie_usage_count = 0; new_size = sec->_raw_size; make_relative = hdr_info->last_cie.make_relative; + make_lsda_relative = hdr_info->last_cie.make_lsda_relative; sec_info = bfd_zmalloc (sizeof (struct eh_frame_sec_info) + 99 * sizeof (struct eh_cie_fde)); if (sec_info == NULL) @@ -418,6 +467,8 @@ _bfd_elf_discard_section_eh_frame (abfd, info, sec, ehdrsec, hdr_info->last_cie_offset = last_cie - ehbuf; sec_info->entry[last_cie_ndx].make_relative = cie.make_relative; + sec_info->entry[last_cie_ndx].make_lsda_relative + = cie.make_lsda_relative; } } @@ -543,6 +594,11 @@ _bfd_elf_discard_section_eh_frame (abfd, info, sec, ehdrsec, && (cie.fde_encoding & 0xf0) == DW_EH_PE_absptr) cie.make_relative = 1; + if (0 + && info->shared + && (cie.lsda_encoding & 0xf0) == DW_EH_PE_absptr) + cie.make_lsda_relative = 1; + /* If FDE encoding was not specified, it defaults to DW_EH_absptr. */ if (cie.fde_encoding == DW_EH_PE_omit) @@ -584,11 +640,24 @@ _bfd_elf_discard_section_eh_frame (abfd, info, sec, ehdrsec, hdr_info->fde_count++; } cookie->rel = rel; + if (cie.lsda_encoding != DW_EH_PE_omit) + { + unsigned int dummy; + + aug = buf; + buf += 2 * get_DW_EH_PE_width (cie.fde_encoding, ptr_size); + if (cie.augmentation[0] == 'z') + read_uleb128 (dummy, buf); + /* If some new augmentation data is added before LSDA + in FDE augmentation area, this need to be adjusted. */ + sec_info->entry[sec_info->count].lsda_offset = (buf - aug); + } buf = last_fde + 4 + hdr.length; SKIP_RELOCS (buf); } sec_info->entry[sec_info->count].fde_encoding = cie.fde_encoding; + sec_info->entry[sec_info->count].lsda_encoding = cie.lsda_encoding; sec_info->count++; } @@ -608,9 +677,13 @@ _bfd_elf_discard_section_eh_frame (abfd, info, sec, ehdrsec, { last_cie_ndx = i; make_relative = sec_info->entry[i].make_relative; + make_lsda_relative = sec_info->entry[i].make_lsda_relative; } else - sec_info->entry[i].make_relative = make_relative; + { + sec_info->entry[i].make_relative = make_relative; + sec_info->entry[i].make_lsda_relative = make_lsda_relative; + } } else if (sec_info->entry[i].cie && sec_info->entry[i].sec == sec) { @@ -781,6 +854,15 @@ _bfd_elf_eh_frame_section_offset (output_bfd, sec, offset) && offset == sec_info->entry[mid].offset + 8) return (bfd_vma) -1; + /* If converting LSDA pointers to DW_EH_PE_pcrel, there will be no need + for run-time relocation against LSDA field. */ + if (sec_info->entry[mid].make_lsda_relative + && ! sec_info->entry[mid].cie + && (offset + == (sec_info->entry[mid].offset + 8 + + sec_info->entry[mid].lsda_offset))) + return (bfd_vma) -1; + return (offset + (sec_info->entry[mid].new_offset - sec_info->entry[mid].offset)); } @@ -845,13 +927,17 @@ _bfd_elf_write_section_eh_frame (abfd, sec, ehdrsec, contents) { /* CIE */ cie_offset = sec_info->entry[i].new_offset; - if (sec_info->entry[i].make_relative) + if (sec_info->entry[i].make_relative + || sec_info->entry[i].make_lsda_relative) { unsigned char *aug; + unsigned int action; unsigned int dummy, per_width, per_encoding; - /* Need to find 'R' augmentation's argument and modify + /* Need to find 'R' or 'L' augmentation's argument and modify DW_EH_PE_* value. */ + action = (sec_info->entry[i].make_relative ? 1 : 0) + | (sec_info->entry[i].make_lsda_relative ? 2 : 0); buf = contents + sec_info->entry[i].offset; /* Skip length, id and version. */ buf += 9; @@ -866,10 +952,16 @@ _bfd_elf_write_section_eh_frame (abfd, sec, ehdrsec, contents) aug++; } - while (*aug != 'R') + while (action) switch (*aug++) { case 'L': + if (action & 2) + { + BFD_ASSERT (*buf == sec_info->entry[i].lsda_encoding); + *buf |= DW_EH_PE_pcrel; + action &= ~2; + } buf++; break; case 'P': @@ -883,19 +975,25 @@ _bfd_elf_write_section_eh_frame (abfd, sec, ehdrsec, contents) & ~((bfd_size_type) per_width - 1))); buf += per_width; break; + case 'R': + if (action & 1) + { + BFD_ASSERT (*buf == sec_info->entry[i].fde_encoding); + *buf |= DW_EH_PE_pcrel; + action &= ~1; + } + buf++; + break; default: BFD_FAIL (); } - - BFD_ASSERT (*buf == sec_info->entry[i].fde_encoding); - *buf |= DW_EH_PE_pcrel; } } else { /* FDE */ bfd_vma value = 0, address; - unsigned int fde_width; + unsigned int width; buf = contents + sec_info->entry[i].offset; /* Skip length. */ @@ -903,45 +1001,36 @@ _bfd_elf_write_section_eh_frame (abfd, sec, ehdrsec, contents) bfd_put_32 (abfd, sec_info->entry[i].new_offset + 4 - cie_offset, buf); buf += 4; - fde_width = get_DW_EH_PE_width (sec_info->entry[i].fde_encoding, - ptr_size); - switch (fde_width) + width = get_DW_EH_PE_width (sec_info->entry[i].fde_encoding, + ptr_size); + address = value = read_value (abfd, buf, width); + if (value) { - case 2: value = bfd_get_16 (abfd, buf); break; - case 4: value = bfd_get_32 (abfd, buf); break; - case 8: value = bfd_get_64 (abfd, buf); break; - default: BFD_FAIL (); - } - address = value; - switch (sec_info->entry[i].fde_encoding & 0xf0) - { - case DW_EH_PE_indirect: - case DW_EH_PE_textrel: - BFD_ASSERT (hdr_info == NULL); - break; - case DW_EH_PE_datarel: - { - asection *got = bfd_get_section_by_name (abfd, ".got"); - - BFD_ASSERT (got != NULL); - address += got->vma; - } - break; - case DW_EH_PE_pcrel: - value += (sec_info->entry[i].offset - - sec_info->entry[i].new_offset); - address += (sec->output_section->vma + sec->output_offset + switch (sec_info->entry[i].fde_encoding & 0xf0) + { + case DW_EH_PE_indirect: + case DW_EH_PE_textrel: + BFD_ASSERT (hdr_info == NULL); + break; + case DW_EH_PE_datarel: + { + asection *got = bfd_get_section_by_name (abfd, ".got"); + + BFD_ASSERT (got != NULL); + address += got->vma; + } + break; + case DW_EH_PE_pcrel: + value += (sec_info->entry[i].offset + - sec_info->entry[i].new_offset); + address += (sec->output_section->vma + sec->output_offset + + sec_info->entry[i].offset + 8); + break; + } + if (sec_info->entry[i].make_relative) + value -= (sec->output_section->vma + sec->output_offset + sec_info->entry[i].new_offset + 8); - break; - } - if (sec_info->entry[i].make_relative) - value -= (sec->output_section->vma + sec->output_offset - + sec_info->entry[i].new_offset + 8); - switch (fde_width) - { - case 2: bfd_put_16 (abfd, value, buf); break; - case 4: bfd_put_32 (abfd, value, buf); break; - case 8: bfd_put_64 (abfd, value, buf); break; + write_value (abfd, buf, value, width); } if (hdr_info) @@ -951,6 +1040,27 @@ _bfd_elf_write_section_eh_frame (abfd, sec, ehdrsec, contents) = (sec->output_section->vma + sec->output_offset + sec_info->entry[i].new_offset); } + + if ((sec_info->entry[i].lsda_encoding & 0xf0) == DW_EH_PE_pcrel + || sec_info->entry[i].make_lsda_relative) + { + buf += sec_info->entry[i].lsda_offset; + width = get_DW_EH_PE_width (sec_info->entry[i].lsda_encoding, + ptr_size); + value = read_value (abfd, buf, width); + if (value) + { + if ((sec_info->entry[i].lsda_encoding & 0xf0) + == DW_EH_PE_pcrel) + value += (sec_info->entry[i].offset + - sec_info->entry[i].new_offset); + else if (sec_info->entry[i].make_lsda_relative) + value -= (sec->output_section->vma + sec->output_offset + + sec_info->entry[i].new_offset + 8 + + sec_info->entry[i].lsda_offset); + write_value (abfd, buf, value, width); + } + } } BFD_ASSERT (p == contents + sec_info->entry[i].new_offset); -- 2.30.2