707 lines
26 KiB
Diff
707 lines
26 KiB
Diff
From ee3beb72e75cdffa08b99e2f9d4829665feccb18 Mon Sep 17 00:00:00 2001
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From: Alan Modra <amodra@gmail.com>
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Date: Sun, 8 Nov 2015 09:29:00 -0800
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Subject: ELF unexec: Don't insert a new section
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Emacs should build on ppc64el. A problem with the bss has been fixed.
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This upstream patch has been added [8/10]:
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ELF unexec: Don't insert a new section
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Reuse the .bss section instead, making it SHT_PROGBITS. This way we
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don't need to mess with symbol st_shndx, or section sh_link and
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sh_info.
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This does lead to eu-elflint complaints about symbols defined in .bss
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with a needed version, because normally it is undefined symbols that
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have needed versions; Defined symbols have version definitions.
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The exception is symbols defined by the linker in .dynbss for
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variables copied from a shared library in order to avoid text
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relocations, with copy relocs to copy their initial values from the
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shared library. These symbols are both defined and have needed
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versions, and eu-elflink only expects to see them in SHT_NOBITS
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sections. Of course there is no real problem with having such symbols
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in SHT_PROGBITS sections. glibc ld.so handles them fine.
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* unexelf.c: Delete outdated comments.
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(PATCH_INDEX): Delete.
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(find_section): Delete.
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(unexec): Don't add a new section. Instead reuse the last bss
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section, extending it to cover dumped data. Make bss sections
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SHT_PROGBITS. Remove all patching of sh_link, sh_info and
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st_shndx. Rename bss sections.
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Origin: upstream, commit: 3008c521740c5ad46a4eaf343b438b02c25e4de5
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Bug: http://debbugs.gnu.org/20614
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Bug-Debian: http://bugs.debian.org/808347
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Added-by: Rob Browning <rlb@defaultvalue.org>
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---
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src/unexelf.c | 526 +++++-----------------------------------------------------
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1 file changed, 51 insertions(+), 475 deletions(-)
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Index: emacs-24.5/src/unexelf.c
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===================================================================
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--- emacs-24.5.orig/src/unexelf.c
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+++ emacs-24.5/src/unexelf.c
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@@ -40,347 +40,6 @@ what you give them. Help stamp out sof
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* On some machines, an existing old_name file is required.
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*
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*/
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-
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-/* Even more heavily modified by james@bigtex.cactus.org of Dell Computer Co.
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- * ELF support added.
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- *
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- * Basic theory: the data space of the running process needs to be
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- * dumped to the output file. Normally we would just enlarge the size
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- * of .data, scooting everything down. But we can't do that in ELF,
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- * because there is often something between the .data space and the
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- * .bss space.
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- *
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- * In the temacs dump below, notice that the Global Offset Table
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- * (.got) and the Dynamic link data (.dynamic) come between .data1 and
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- * .bss. It does not work to overlap .data with these fields.
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- *
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- * The solution is to create a new .data segment. This segment is
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- * filled with data from the current process. Since the contents of
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- * various sections refer to sections by index, the new .data segment
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- * is made the last in the table to avoid changing any existing index.
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-
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- * This is an example of how the section headers are changed. "Addr"
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- * is a process virtual address. "Offset" is a file offset.
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-
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-raid:/nfs/raid/src/dist-18.56/src> dump -h temacs
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-
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-temacs:
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-
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- **** SECTION HEADER TABLE ****
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- [No] Type Flags Addr Offset Size Name
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- Link Info Adralgn Entsize
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-
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- [1] 1 2 0x80480d4 0xd4 0x13 .interp
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- 0 0 0x1 0
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-
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- [2] 5 2 0x80480e8 0xe8 0x388 .hash
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- 3 0 0x4 0x4
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-
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- [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
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- 4 1 0x4 0x10
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-
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- [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
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- 0 0 0x1 0
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-
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- [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
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- 3 7 0x4 0x8
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-
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- [6] 1 6 0x8049348 0x1348 0x3 .init
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- 0 0 0x4 0
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-
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- [7] 1 6 0x804934c 0x134c 0x680 .plt
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- 0 0 0x4 0x4
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-
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- [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
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- 0 0 0x4 0
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-
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- [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
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- 0 0 0x4 0
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-
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- [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
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- 0 0 0x4 0
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-
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- [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
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- 0 0 0x4 0
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-
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- [12] 1 3 0x8088330 0x3f330 0x20afc .data
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- 0 0 0x4 0
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-
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- [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
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- 0 0 0x4 0
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-
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- [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
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- 0 0 0x4 0x4
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-
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- [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
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- 4 0 0x4 0x8
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-
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- [16] 8 3 0x80a98f4 0x608f4 0x449c .bss
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- 0 0 0x4 0
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-
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- [17] 2 0 0 0x608f4 0x9b90 .symtab
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- 18 371 0x4 0x10
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-
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- [18] 3 0 0 0x6a484 0x8526 .strtab
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- 0 0 0x1 0
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-
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- [19] 3 0 0 0x729aa 0x93 .shstrtab
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- 0 0 0x1 0
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-
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- [20] 1 0 0 0x72a3d 0x68b7 .comment
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- 0 0 0x1 0
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-
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- raid:/nfs/raid/src/dist-18.56/src> dump -h xemacs
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-
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- xemacs:
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-
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- **** SECTION HEADER TABLE ****
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- [No] Type Flags Addr Offset Size Name
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- Link Info Adralgn Entsize
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-
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- [1] 1 2 0x80480d4 0xd4 0x13 .interp
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- 0 0 0x1 0
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-
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- [2] 5 2 0x80480e8 0xe8 0x388 .hash
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- 3 0 0x4 0x4
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-
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- [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
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- 4 1 0x4 0x10
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-
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- [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
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- 0 0 0x1 0
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-
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- [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
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- 3 7 0x4 0x8
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-
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- [6] 1 6 0x8049348 0x1348 0x3 .init
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- 0 0 0x4 0
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-
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- [7] 1 6 0x804934c 0x134c 0x680 .plt
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- 0 0 0x4 0x4
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-
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- [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
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- 0 0 0x4 0
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-
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- [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
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- 0 0 0x4 0
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-
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- [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
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- 0 0 0x4 0
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-
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- [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
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- 0 0 0x4 0
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-
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- [12] 1 3 0x8088330 0x3f330 0x20afc .data
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- 0 0 0x4 0
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-
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- [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
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- 0 0 0x4 0
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-
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- [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
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- 0 0 0x4 0x4
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-
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- [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
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- 4 0 0x4 0x8
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-
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- [16] 8 3 0x80c6800 0x7d800 0 .bss
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- 0 0 0x4 0
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-
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- [17] 2 0 0 0x7d800 0x9b90 .symtab
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- 18 371 0x4 0x10
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-
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- [18] 3 0 0 0x87390 0x8526 .strtab
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- 0 0 0x1 0
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-
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- [19] 3 0 0 0x8f8b6 0x93 .shstrtab
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- 0 0 0x1 0
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-
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- [20] 1 0 0 0x8f949 0x68b7 .comment
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- 0 0 0x1 0
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-
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- [21] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
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- 0 0 0x4 0
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-
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- * This is an example of how the file header is changed. "Shoff" is
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- * the section header offset within the file. Since that table is
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- * after the new .data section, it is moved. "Shnum" is the number of
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- * sections, which we increment.
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- *
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- * "Phoff" is the file offset to the program header. "Phentsize" and
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- * "Shentsz" are the program and section header entries sizes respectively.
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- * These can be larger than the apparent struct sizes.
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-
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- raid:/nfs/raid/src/dist-18.56/src> dump -f temacs
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-
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- temacs:
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-
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- **** ELF HEADER ****
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- Class Data Type Machine Version
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- Entry Phoff Shoff Flags Ehsize
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- Phentsize Phnum Shentsz Shnum Shstrndx
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-
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- 1 1 2 3 1
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- 0x80499cc 0x34 0x792f4 0 0x34
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- 0x20 5 0x28 21 19
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-
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- raid:/nfs/raid/src/dist-18.56/src> dump -f xemacs
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-
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- xemacs:
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-
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- **** ELF HEADER ****
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- Class Data Type Machine Version
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- Entry Phoff Shoff Flags Ehsize
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- Phentsize Phnum Shentsz Shnum Shstrndx
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-
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- 1 1 2 3 1
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- 0x80499cc 0x34 0x96200 0 0x34
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- 0x20 5 0x28 22 19
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-
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- * These are the program headers. "Offset" is the file offset to the
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- * segment. "Vaddr" is the memory load address. "Filesz" is the
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- * segment size as it appears in the file, and "Memsz" is the size in
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- * memory. Below, the third segment is the code and the fourth is the
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- * data: the difference between Filesz and Memsz is .bss
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-
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- raid:/nfs/raid/src/dist-18.56/src> dump -o temacs
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-
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- temacs:
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- ***** PROGRAM EXECUTION HEADER *****
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- Type Offset Vaddr Paddr
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- Filesz Memsz Flags Align
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-
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- 6 0x34 0x8048034 0
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- 0xa0 0xa0 5 0
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-
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- 3 0xd4 0 0
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- 0x13 0 4 0
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-
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- 1 0x34 0x8048034 0
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- 0x3f2f9 0x3f2f9 5 0x1000
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-
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- 1 0x3f330 0x8088330 0
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- 0x215c4 0x25a60 7 0x1000
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-
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- 2 0x60874 0x80a9874 0
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- 0x80 0 7 0
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-
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- raid:/nfs/raid/src/dist-18.56/src> dump -o xemacs
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-
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- xemacs:
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- ***** PROGRAM EXECUTION HEADER *****
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- Type Offset Vaddr Paddr
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- Filesz Memsz Flags Align
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-
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- 6 0x34 0x8048034 0
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- 0xa0 0xa0 5 0
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-
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- 3 0xd4 0 0
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- 0x13 0 4 0
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-
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- 1 0x34 0x8048034 0
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- 0x3f2f9 0x3f2f9 5 0x1000
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-
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- 1 0x3f330 0x8088330 0
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- 0x3e4d0 0x3e4d0 7 0x1000
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-
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- 2 0x60874 0x80a9874 0
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- 0x80 0 7 0
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-
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-
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- */
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-
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-/* Modified by wtien@urbana.mcd.mot.com of Motorola Inc.
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- *
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- * The above mechanism does not work if the unexeced ELF file is being
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- * re-layout by other applications (such as `strip'). All the applications
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- * that re-layout the internal of ELF will layout all sections in ascending
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- * order of their file offsets. After the re-layout, the data2 section will
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- * still be the LAST section in the section header vector, but its file offset
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- * is now being pushed far away down, and causes part of it not to be mapped
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- * in (ie. not covered by the load segment entry in PHDR vector), therefore
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- * causes the new binary to fail.
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- *
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- * The solution is to modify the unexec algorithm to insert the new data2
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- * section header right before the new bss section header, so their file
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- * offsets will be in the ascending order. Since some of the section's (all
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- * sections AFTER the bss section) indexes are now changed, we also need to
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- * modify some fields to make them point to the right sections. This is done
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- * by macro PATCH_INDEX. All the fields that need to be patched are:
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- *
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- * 1. ELF header e_shstrndx field.
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- * 2. section header sh_link and sh_info field.
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- * 3. symbol table entry st_shndx field.
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- *
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- * The above example now should look like:
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-
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- **** SECTION HEADER TABLE ****
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- [No] Type Flags Addr Offset Size Name
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- Link Info Adralgn Entsize
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-
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- [1] 1 2 0x80480d4 0xd4 0x13 .interp
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- 0 0 0x1 0
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-
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- [2] 5 2 0x80480e8 0xe8 0x388 .hash
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- 3 0 0x4 0x4
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-
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- [3] 11 2 0x8048470 0x470 0x7f0 .dynsym
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- 4 1 0x4 0x10
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-
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- [4] 3 2 0x8048c60 0xc60 0x3ad .dynstr
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- 0 0 0x1 0
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-
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- [5] 9 2 0x8049010 0x1010 0x338 .rel.plt
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- 3 7 0x4 0x8
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-
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- [6] 1 6 0x8049348 0x1348 0x3 .init
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- 0 0 0x4 0
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-
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- [7] 1 6 0x804934c 0x134c 0x680 .plt
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- 0 0 0x4 0x4
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-
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- [8] 1 6 0x80499cc 0x19cc 0x3c56f .text
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- 0 0 0x4 0
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-
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- [9] 1 6 0x8085f3c 0x3df3c 0x3 .fini
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- 0 0 0x4 0
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-
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- [10] 1 2 0x8085f40 0x3df40 0x69c .rodata
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- 0 0 0x4 0
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-
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- [11] 1 2 0x80865dc 0x3e5dc 0xd51 .rodata1
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- 0 0 0x4 0
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-
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- [12] 1 3 0x8088330 0x3f330 0x20afc .data
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- 0 0 0x4 0
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-
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- [13] 1 3 0x80a8e2c 0x5fe2c 0x89d .data1
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- 0 0 0x4 0
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-
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- [14] 1 3 0x80a96cc 0x606cc 0x1a8 .got
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- 0 0 0x4 0x4
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-
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- [15] 6 3 0x80a9874 0x60874 0x80 .dynamic
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- 4 0 0x4 0x8
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-
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- [16] 1 3 0x80a98f4 0x608f4 0x1cf0c .data
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- 0 0 0x4 0
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-
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- [17] 8 3 0x80c6800 0x7d800 0 .bss
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- 0 0 0x4 0
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-
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- [18] 2 0 0 0x7d800 0x9b90 .symtab
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- 19 371 0x4 0x10
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-
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- [19] 3 0 0 0x87390 0x8526 .strtab
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- 0 0 0x1 0
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-
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- [20] 3 0 0 0x8f8b6 0x93 .shstrtab
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- 0 0 0x1 0
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-
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- [21] 1 0 0 0x8f949 0x68b7 .comment
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- 0 0 0x1 0
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-
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- */
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/* We do not use mmap because that fails with NFS.
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Instead we read the whole file, modify it, and write it out. */
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@@ -552,45 +211,15 @@ entry_address (void *section_h, ptrdiff_
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#define NEW_PROGRAM_H(n) \
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(*(ElfW (Phdr) *) entry_address (new_program_h, n, new_file_h->e_phentsize))
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-#define PATCH_INDEX(n) ((n) += old_bss_index <= (n))
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typedef unsigned char byte;
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-/* Return the index of the section named NAME.
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- SECTION_NAMES, FILE_NAME and FILE_H give information
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- about the file we are looking in.
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-
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- If we don't find the section NAME, that is a fatal error
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- if NOERROR is false; return -1 if NOERROR is true. */
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-
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-static ptrdiff_t
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-find_section (const char *name, const char *section_names, const char *file_name,
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- ElfW (Ehdr) *old_file_h, ElfW (Shdr) *old_section_h,
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- bool noerror)
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-{
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- ptrdiff_t idx;
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-
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- for (idx = 1; idx < old_file_h->e_shnum; idx++)
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- {
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- char const *found_name = section_names + OLD_SECTION_H (idx).sh_name;
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-#ifdef UNEXELF_DEBUG
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- fprintf (stderr, "Looking for %s - found %s\n", name, found_name);
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-#endif
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- if (strcmp (name, found_name) == 0)
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- return idx;
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- }
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-
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- if (! noerror)
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- fatal ("Can't find %s in %s", name, file_name);
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- return -1;
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-}
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-
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/* ****************************************************************
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* unexec
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*
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* driving logic.
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*
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- * In ELF, this works by replacing the old .bss section with a new
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- * .data section, and inserting an empty .bss immediately afterwards.
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+ * In ELF, this works by replacing the old bss SHT_NOBITS section with
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+ * a new, larger, SHT_PROGBITS section.
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*
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*/
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void
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@@ -615,18 +244,16 @@ unexec (const char *new_name, const char
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ElfW (Phdr) *old_program_h, *new_program_h;
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ElfW (Shdr) *old_section_h, *new_section_h;
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- /* Point to the section name table in the old file. */
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- char *old_section_names;
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+ /* Point to the section name table. */
|
||
+ char *old_section_names, *new_section_names;
|
||
|
||
ElfW (Phdr) *old_bss_seg, *new_bss_seg;
|
||
ElfW (Addr) old_bss_addr, new_bss_addr;
|
||
ElfW (Word) old_bss_size, new_data2_size;
|
||
- ElfW (Off) new_data2_offset;
|
||
- ElfW (Addr) new_data2_addr;
|
||
- ElfW (Off) old_bss_offset;
|
||
+ ElfW (Off) old_bss_offset, new_data2_offset;
|
||
|
||
- ptrdiff_t n, nn;
|
||
- ptrdiff_t old_bss_index, old_data_index;
|
||
+ ptrdiff_t n;
|
||
+ ptrdiff_t old_bss_index;
|
||
struct stat stat_buf;
|
||
off_t old_file_size;
|
||
int mask;
|
||
@@ -689,7 +316,7 @@ unexec (const char *new_name, const char
|
||
old_bss_offset = old_bss_seg->p_offset + old_bss_seg->p_filesz;
|
||
old_bss_size = old_bss_seg->p_memsz - old_bss_seg->p_filesz;
|
||
|
||
- /* Find the first bss style section in the bss segment range. */
|
||
+ /* Find the last bss style section in the bss segment range. */
|
||
old_bss_index = -1;
|
||
for (n = old_file_h->e_shnum; --n > 0; )
|
||
{
|
||
@@ -698,22 +325,15 @@ unexec (const char *new_name, const char
|
||
&& shdr->sh_addr >= old_bss_addr
|
||
&& shdr->sh_addr + shdr->sh_size <= old_bss_addr + old_bss_size
|
||
&& (old_bss_index == -1
|
||
- || OLD_SECTION_H (old_bss_index).sh_addr > shdr->sh_addr))
|
||
+ || OLD_SECTION_H (old_bss_index).sh_addr < shdr->sh_addr))
|
||
old_bss_index = n;
|
||
}
|
||
|
||
if (old_bss_index == -1)
|
||
fatal ("no bss section found");
|
||
|
||
- /* Find the old .data section. Figure out parameters of
|
||
- the new data2 and bss sections. */
|
||
-
|
||
- old_data_index = find_section (".data", old_section_names,
|
||
- old_name, old_file_h, old_section_h, 0);
|
||
-
|
||
new_break = sbrk (0);
|
||
new_bss_addr = (ElfW (Addr)) new_break;
|
||
- new_data2_addr = old_bss_addr;
|
||
new_data2_size = new_bss_addr - old_bss_addr;
|
||
new_data2_offset = old_bss_offset;
|
||
|
||
@@ -723,7 +343,6 @@ unexec (const char *new_name, const char
|
||
DEBUG_LOG (old_bss_size);
|
||
DEBUG_LOG (old_bss_offset);
|
||
DEBUG_LOG (new_bss_addr);
|
||
- DEBUG_LOG (new_data2_addr);
|
||
DEBUG_LOG (new_data2_size);
|
||
DEBUG_LOG (new_data2_offset);
|
||
#endif
|
||
@@ -739,7 +358,7 @@ unexec (const char *new_name, const char
|
||
if (new_file < 0)
|
||
fatal ("Can't creat (%s): %s", new_name, strerror (errno));
|
||
|
||
- new_file_size = old_file_size + old_file_h->e_shentsize + new_data2_size;
|
||
+ new_file_size = old_file_size + new_data2_size;
|
||
|
||
if (ftruncate (new_file, new_file_size))
|
||
fatal ("Can't ftruncate (%s): %s", new_name, strerror (errno));
|
||
@@ -755,21 +374,18 @@ unexec (const char *new_name, const char
|
||
new_file_h = (ElfW (Ehdr) *) new_base;
|
||
memcpy (new_file_h, old_file_h, old_file_h->e_ehsize);
|
||
|
||
- /* Fix up file header. We'll add one section. Section header is
|
||
- further away now. */
|
||
+ /* Fix up file header. Section header is further away now. */
|
||
|
||
if (new_file_h->e_shoff >= old_bss_offset)
|
||
new_file_h->e_shoff += new_data2_size;
|
||
- new_file_h->e_shnum += 1;
|
||
-
|
||
- /* Modify the e_shstrndx if necessary. */
|
||
- PATCH_INDEX (new_file_h->e_shstrndx);
|
||
|
||
new_program_h = (ElfW (Phdr) *) ((byte *) new_base + new_file_h->e_phoff);
|
||
new_section_h = (ElfW (Shdr) *) ((byte *) new_base + new_file_h->e_shoff);
|
||
|
||
memcpy (new_program_h, old_program_h,
|
||
old_file_h->e_phnum * old_file_h->e_phentsize);
|
||
+ memcpy (new_section_h, old_section_h,
|
||
+ old_file_h->e_shnum * old_file_h->e_shentsize);
|
||
|
||
#ifdef UNEXELF_DEBUG
|
||
DEBUG_LOG (old_file_h->e_shoff);
|
||
@@ -788,42 +404,21 @@ unexec (const char *new_name, const char
|
||
/* Copy over what we have in memory now for the bss area. */
|
||
memcpy (new_base + new_data2_offset, (caddr_t) old_bss_addr, new_data2_size);
|
||
|
||
- /* Fix up section headers based on new .data2 section. Any section
|
||
- whose offset or virtual address is after the new .data2 section
|
||
- gets its value adjusted. .bss size becomes zero. data2 section
|
||
- header gets added by copying the existing .data header and
|
||
- modifying the offset, address and size. */
|
||
-
|
||
- /* Walk through all section headers, insert the new data2 section right
|
||
- before the new bss section. */
|
||
- for (n = 1, nn = 1; n < old_file_h->e_shnum; n++, nn++)
|
||
+ /* Walk through all section headers, copying data and updating. */
|
||
+ for (n = 1; n < old_file_h->e_shnum; n++)
|
||
{
|
||
caddr_t src;
|
||
ElfW (Shdr) *old_shdr = &OLD_SECTION_H (n);
|
||
- ElfW (Shdr) *new_shdr = &NEW_SECTION_H (nn);
|
||
-
|
||
- /* If it is (s)bss section, insert the new data2 section before it. */
|
||
- if (n == old_bss_index)
|
||
- {
|
||
- /* Steal the data section header for this data2 section. */
|
||
- memcpy (new_shdr, &OLD_SECTION_H (old_data_index),
|
||
- new_file_h->e_shentsize);
|
||
-
|
||
- new_shdr->sh_addr = new_data2_addr;
|
||
- new_shdr->sh_offset = new_data2_offset;
|
||
- new_shdr->sh_size = new_data2_size;
|
||
- new_shdr->sh_addralign = 1;
|
||
- nn++;
|
||
- new_shdr++;
|
||
- }
|
||
-
|
||
- memcpy (new_shdr, old_shdr, old_file_h->e_shentsize);
|
||
+ ElfW (Shdr) *new_shdr = &NEW_SECTION_H (n);
|
||
|
||
if (new_shdr->sh_type == SHT_NOBITS
|
||
&& new_shdr->sh_addr >= old_bss_addr
|
||
&& (new_shdr->sh_addr + new_shdr->sh_size
|
||
<= old_bss_addr + old_bss_size))
|
||
{
|
||
+ /* This section now has file backing. */
|
||
+ new_shdr->sh_type = SHT_PROGBITS;
|
||
+
|
||
/* SHT_NOBITS sections do not need a valid sh_offset, so it
|
||
might be incorrect. Write the correct value. */
|
||
new_shdr->sh_offset = (new_shdr->sh_addr - new_bss_seg->p_vaddr
|
||
@@ -838,35 +433,20 @@ unexec (const char *new_name, const char
|
||
if (strcmp (old_section_names + new_shdr->sh_name, ".plt") == 0)
|
||
memset (new_shdr->sh_offset + new_base, 0, new_shdr->sh_size);
|
||
|
||
- /* Set the new bss and sbss section's size to zero, because
|
||
- we've already covered this address range by .data2. */
|
||
- new_shdr->sh_size = 0;
|
||
- }
|
||
- else
|
||
- {
|
||
- /* Any section that was originally placed after the .bss
|
||
- section should now be off by NEW_DATA2_SIZE. */
|
||
-
|
||
- if (new_shdr->sh_offset >= old_bss_offset)
|
||
- new_shdr->sh_offset += new_data2_size;
|
||
-
|
||
- /* Any section that was originally placed after the section
|
||
- header table should now be off by the size of one section
|
||
- header table entry. */
|
||
- if (new_shdr->sh_offset > new_file_h->e_shoff)
|
||
- new_shdr->sh_offset += new_file_h->e_shentsize;
|
||
+ /* Extend the size of the last bss section to cover dumped
|
||
+ data. */
|
||
+ if (n == old_bss_index)
|
||
+ new_shdr->sh_size = new_bss_addr - new_shdr->sh_addr;
|
||
+
|
||
+ /* We have already copied this section from the current
|
||
+ process. */
|
||
+ continue;
|
||
}
|
||
|
||
- /* If any section hdr refers to the section after the new .data
|
||
- section, make it refer to next one because we have inserted
|
||
- a new section in between. */
|
||
-
|
||
- PATCH_INDEX (new_shdr->sh_link);
|
||
- /* For symbol tables, info is a symbol table index,
|
||
- so don't change it. */
|
||
- if (new_shdr->sh_type != SHT_SYMTAB
|
||
- && new_shdr->sh_type != SHT_DYNSYM)
|
||
- PATCH_INDEX (new_shdr->sh_info);
|
||
+ /* Any section that was originally placed after the .bss
|
||
+ section should now be offset by NEW_DATA2_SIZE. */
|
||
+ if (new_shdr->sh_offset >= old_bss_offset)
|
||
+ new_shdr->sh_offset += new_data2_size;
|
||
|
||
/* Now, start to copy the content of sections. */
|
||
if (new_shdr->sh_type == SHT_NULL
|
||
@@ -982,24 +562,6 @@ unexec (const char *new_name, const char
|
||
}
|
||
}
|
||
#endif /* __sgi */
|
||
-
|
||
- /* Patch st_shndx field of symbol table. */
|
||
- if (new_shdr->sh_type == SHT_SYMTAB
|
||
- || new_shdr->sh_type == SHT_DYNSYM)
|
||
- {
|
||
- ptrdiff_t num = new_shdr->sh_size / new_shdr->sh_entsize;
|
||
- ElfW (Sym) *sym = (ElfW (Sym) *) (new_shdr->sh_offset + new_base);
|
||
- for (; num--; sym++)
|
||
- {
|
||
- if (sym->st_shndx == SHN_XINDEX)
|
||
- fatal ("SHT_SYMTAB_SHNDX unsupported");
|
||
- if (sym->st_shndx == SHN_UNDEF
|
||
- || sym->st_shndx >= SHN_LORESERVE)
|
||
- continue;
|
||
-
|
||
- PATCH_INDEX (sym->st_shndx);
|
||
- }
|
||
- }
|
||
}
|
||
|
||
/* Update the symbol values of _edata and _end. */
|
||
@@ -1043,15 +605,10 @@ unexec (const char *new_name, const char
|
||
ElfW (Shdr) *new_shdr = &NEW_SECTION_H (symp->st_shndx);
|
||
if (new_shdr->sh_type != SHT_NOBITS)
|
||
{
|
||
- ElfW (Shdr) *old_shdr;
|
||
+ ElfW (Shdr) *old_shdr = &OLD_SECTION_H (symp->st_shndx);
|
||
ptrdiff_t reladdr = symp->st_value - new_shdr->sh_addr;
|
||
ptrdiff_t newoff = reladdr + new_shdr->sh_offset;
|
||
|
||
- /* "Unpatch" index. */
|
||
- nn = symp->st_shndx;
|
||
- if (nn > old_bss_index)
|
||
- nn--;
|
||
- old_shdr = &OLD_SECTION_H (nn);
|
||
if (old_shdr->sh_type == SHT_NOBITS)
|
||
memset (new_base + newoff, 0, symp->st_size);
|
||
else
|
||
@@ -1066,6 +623,25 @@ unexec (const char *new_name, const char
|
||
}
|
||
}
|
||
|
||
+ /* Modify the names of sections we changed from SHT_NOBITS to
|
||
+ SHT_PROGBITS. This is really just cosmetic, but some tools that
|
||
+ (wrongly) operate on section names rather than types might be
|
||
+ confused by a SHT_PROGBITS .bss section. */
|
||
+ new_section_names = ((char *) new_base
|
||
+ + NEW_SECTION_H (new_file_h->e_shstrndx).sh_offset);
|
||
+ for (n = new_file_h->e_shnum; 0 < --n; )
|
||
+ {
|
||
+ ElfW (Shdr) *old_shdr = &OLD_SECTION_H (n);
|
||
+ ElfW (Shdr) *new_shdr = &NEW_SECTION_H (n);
|
||
+
|
||
+ /* Replace the leading '.' with ','. When .shstrtab is string
|
||
+ merged this will rename both .bss and .rela.bss to ,bss and
|
||
+ .rela,bss. */
|
||
+ if (old_shdr->sh_type == SHT_NOBITS
|
||
+ && new_shdr->sh_type == SHT_PROGBITS)
|
||
+ *(new_section_names + new_shdr->sh_name) = ',';
|
||
+ }
|
||
+
|
||
/* This loop seeks out relocation sections for the data section, so
|
||
that it can undo relocations performed by the runtime loader. */
|
||
for (n = new_file_h->e_shnum; 0 < --n; )
|