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More progress on parsing elf files. Fixes to memfs file read/write

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Increased inode block pointers to 40. The current maximum allowed (and checked).
Updates to file size after every file write ensures subsequent writes can
correctly operate using updated file size information (i.e. not try to add
more pages that are already present). We cannot do this inside write() because
directory writes rely on byte-granularity updates on file buffers, whereas
file updates are by page-granularity (currently).
This commit is contained in:
Bahadir Balban
2008-11-21 19:26:10 +02:00
parent 27d331895b
commit 2d5a08ff32
15 changed files with 187 additions and 30 deletions
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60
tasks/mm0/src/lib/elf/elf.c
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@@ -4,10 +4,10 @@
* Copyright (C) 2008 Bahadir Balban
*/
#include <vm_area.h>
#include <lib/elf.h>
#include <lib/elfprg.h>
#include <lib/elfsym.h>
#include <lib/elfsect.h>
#include <lib/elf/elf.h>
#include <lib/elf/elfprg.h>
#include <lib/elf/elfsym.h>
#include <lib/elf/elfsect.h>
int elf_probe(struct elf_header *header)
@@ -32,8 +32,7 @@ int elf_probe(struct elf_header *header)
* only) segment that has type LOAD. Then it looks at the section header
* table, to find out about every loadable section that is part of this
* aforementioned loadable program segment. Each section is marked in the
* efd and tcb structures for further memory mappings. Loading an elf
* executable is simple as that, but it is described poorly in manuals.
* efd and tcb structures for further memory mappings.
*/
int elf_parse_executable(struct tcb *task, struct vm_file *file,
struct exec_file_desc *efd)
@@ -41,7 +40,7 @@ int elf_parse_executable(struct tcb *task, struct vm_file *file,
int err;
struct elf_header *elf_header = pager_map_page(file, 0);
struct elf_program_header *prg_header_start, *prg_header_load;
struct elf_section_header *sect_header_start;
struct elf_section_header *sect_header;
/* Test that it is a valid elf file */
if ((err = elf_probe(elf_header)) < 0)
@@ -53,14 +52,55 @@ int elf_parse_executable(struct tcb *task, struct vm_file *file,
/* Get the first loadable segment */
for (int i = 0; i < elf_header->e_phnum; i++) {
if (prg_header_start[i].type == PT_LOAD) {
if (prg_header_start[i].p_type == PT_LOAD) {
prg_header_load = &prg_header_start[i];
break;
}
}
/* Get the section header table */
sect_header_start = (struct elf_section_header *)
((void *)elf_header + elf_header->e_shoff);
sect_header = (struct elf_section_header *)
((void *)elf_header + elf_header->e_shoff);
/*
* Sift through sections and copy their marks to tcb and efd
* if they are recognised and loadable sections.
*
* NOTE: There may be multiple sections of same kind, in
* consecutive address regions. Then we need to increase
* that region's marks.
*/
for (int i = 0; i < elf_header->e_shnum; i++) {
struct elf_section_header *section = &sect_header[i];
/* Text section */
if (section->sh_type == SHT_PROGBITS &&
section->sh_flags & SHF_ALLOC &&
section->sh_flags & SHF_EXECINSTR) {
efd->text_offset = section->sh_offset;
task->text_start = section->sh_addr;
task->text_end = section->sh_addr + section->sh_size;
}
/* Data section */
if (section->sh_type == SHT_PROGBITS &&
section->sh_flags & SHF_ALLOC &&
section->sh_flags & SHF_WRITE) {
efd->data_offset = section->sh_offset;
task->data_start = section->sh_addr;
task->data_end = section->sh_addr + section->sh_size;
}
/* BSS section */
if (section->sh_type == SHT_NOBITS &&
section->sh_flags & SHF_ALLOC &&
section->sh_flags & SHF_WRITE) {
efd->bss_offset = section->sh_offset;
task->bss_start = section->sh_addr;
task->bss_end = section->sh_addr + section->sh_size;
}
}
return 0;
}