lkml.org 
[lkml]   [2003]   [Feb]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] Modules code tidy up
Date
Linus, please apply.

Now we search for 11 different sections by name, the if/else was
getting unwieldy. Also, handle_section just does relocs, so it's a
bit of a misnomer, and it's best simply moved into the main code.

Thanks,
Rusty.

Name: Tidy Up module.c
Author: Rusty Russell
Status: Tested on 2.5.63

D: This open-codes handle_section, which simply does relocations now
D: Also adds "find_sec" and uses it to find the various sections.

diff -urpN --exclude TAGS -X /home/rusty/devel/kernel/kernel-patches/current-dontdiff --minimal linux-2.5.62-bk1/kernel/module.c working-2.5.62-bk1-modclean/kernel/module.c
--- linux-2.5.62-bk1/kernel/module.c 2003-02-18 11:18:57.000000000 +1100
+++ working-2.5.62-bk1-modclean/kernel/module.c 2003-02-19 22:22:19.000000000 +1100
@@ -76,6 +76,22 @@ int init_module(void)
}
EXPORT_SYMBOL(init_module);

+/* Find a module section: 0 means not found. */
+static unsigned int find_sec(Elf_Ehdr *hdr,
+ Elf_Shdr *sechdrs,
+ const char *secstrings,
+ const char *name)
+{
+ unsigned int i;
+
+ for (i = 1; i < hdr->e_shnum; i++)
+ /* Alloc bit cleared means "ignore it." */
+ if ((sechdrs[i].sh_flags & SHF_ALLOC)
+ && strcmp(secstrings+sechdrs[i].sh_name, name) == 0)
+ return i;
+ return 0;
+}
+
/* Find a symbol, return value and the symbol group */
static unsigned long __find_symbol(const char *name,
struct kernel_symbol_group **group,
@@ -875,45 +891,6 @@ void *__symbol_get(const char *symbol)
}
EXPORT_SYMBOL_GPL(__symbol_get);

-/* Deal with the given section */
-static int handle_section(const char *name,
- Elf_Shdr *sechdrs,
- unsigned int strindex,
- unsigned int symindex,
- unsigned int i,
- struct module *mod)
-{
- int ret;
- const char *strtab = (char *)sechdrs[strindex].sh_addr;
-
- switch (sechdrs[i].sh_type) {
- case SHT_REL:
- ret = apply_relocate(sechdrs, strtab, symindex, i, mod);
- break;
- case SHT_RELA:
- ret = apply_relocate_add(sechdrs, strtab, symindex, i, mod);
- break;
- default:
- DEBUGP("Ignoring section %u: %s\n", i,
- sechdrs[i].sh_type==SHT_NULL ? "NULL":
- sechdrs[i].sh_type==SHT_PROGBITS ? "PROGBITS":
- sechdrs[i].sh_type==SHT_SYMTAB ? "SYMTAB":
- sechdrs[i].sh_type==SHT_STRTAB ? "STRTAB":
- sechdrs[i].sh_type==SHT_RELA ? "RELA":
- sechdrs[i].sh_type==SHT_HASH ? "HASH":
- sechdrs[i].sh_type==SHT_DYNAMIC ? "DYNAMIC":
- sechdrs[i].sh_type==SHT_NOTE ? "NOTE":
- sechdrs[i].sh_type==SHT_NOBITS ? "NOBITS":
- sechdrs[i].sh_type==SHT_REL ? "REL":
- sechdrs[i].sh_type==SHT_SHLIB ? "SHLIB":
- sechdrs[i].sh_type==SHT_DYNSYM ? "DYNSYM":
- sechdrs[i].sh_type==SHT_NUM ? "NUM":
- "UNKNOWN");
- ret = 0;
- }
- return ret;
-}
-
/* Change all symbols so that sh_value encodes the pointer directly. */
static int simplify_symbols(Elf_Shdr *sechdrs,
unsigned int symindex,
@@ -1103,93 +1080,16 @@ static struct module *load_module(void *
sechdrs = (void *)hdr + hdr->e_shoff;
secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;

- /* May not export symbols, or have setup params, so these may
- not exist */
- exportindex = setupindex = obsparmindex = gplindex = licenseindex
- = crcindex = gplcrcindex = versindex = 0;
-
- /* And these should exist, but gcc whinges if we don't init them */
- symindex = strindex = exindex = modindex = vmagindex = 0;
-
- /* Find where important sections are */
for (i = 1; i < hdr->e_shnum; i++) {
/* Mark all sections sh_addr with their address in the
temporary image. */
sechdrs[i].sh_addr = (size_t)hdr + sechdrs[i].sh_offset;

+ /* Internal symbols and strings. */
if (sechdrs[i].sh_type == SHT_SYMTAB) {
- /* Internal symbols */
- DEBUGP("Symbol table in section %u\n", i);
symindex = i;
- /* Strings */
strindex = sechdrs[i].sh_link;
- DEBUGP("String table found in section %u\n", strindex);
- } else if (strcmp(secstrings+sechdrs[i].sh_name,
- ".gnu.linkonce.this_module") == 0) {
- /* The module struct */
- DEBUGP("Module in section %u\n", i);
- modindex = i;
- } else if (strcmp(secstrings+sechdrs[i].sh_name, "__ksymtab")
- == 0) {
- /* Exported symbols. */
- DEBUGP("EXPORT table in section %u\n", i);
- exportindex = i;
- } else if (strcmp(secstrings+sechdrs[i].sh_name,
- "__ksymtab_gpl") == 0) {
- /* Exported symbols. (GPL) */
- DEBUGP("GPL symbols found in section %u\n", i);
- gplindex = i;
- } else if (strcmp(secstrings+sechdrs[i].sh_name, "__kcrctab")
- == 0) {
- /* Exported symbols CRCs. */
- DEBUGP("CRC table in section %u\n", i);
- crcindex = i;
- } else if (strcmp(secstrings+sechdrs[i].sh_name, "__kcrctab_gpl")
- == 0) {
- /* Exported symbols CRCs. (GPL)*/
- DEBUGP("CRC table in section %u\n", i);
- gplcrcindex = i;
- } else if (strcmp(secstrings+sechdrs[i].sh_name, "__param")
- == 0) {
- /* Setup parameter info */
- DEBUGP("Setup table found in section %u\n", i);
- setupindex = i;
- } else if (strcmp(secstrings+sechdrs[i].sh_name, "__ex_table")
- == 0) {
- /* Exception table */
- DEBUGP("Exception table found in section %u\n", i);
- exindex = i;
- } else if (strcmp(secstrings+sechdrs[i].sh_name, "__obsparm")
- == 0) {
- /* Obsolete MODULE_PARM() table */
- DEBUGP("Obsolete param found in section %u\n", i);
- obsparmindex = i;
- } else if (strcmp(secstrings+sechdrs[i].sh_name,".init.license")
- == 0) {
- /* MODULE_LICENSE() */
- DEBUGP("Licence found in section %u\n", i);
- licenseindex = i;
- sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
- } else if (strcmp(secstrings+sechdrs[i].sh_name,
- "__vermagic") == 0 &&
- (sechdrs[i].sh_flags & SHF_ALLOC)) {
- /* Version magic. */
- DEBUGP("Version magic found in section %u\n", i);
- vmagindex = i;
- sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
- } else if (strcmp(secstrings+sechdrs[i].sh_name,
- "__versions") == 0 &&
- (sechdrs[i].sh_flags & SHF_ALLOC)) {
- /* Module version info (both exported and needed) */
- DEBUGP("Versions found in section %u\n", i);
- versindex = i;
- sechdrs[i].sh_flags &= ~(unsigned long)SHF_ALLOC;
}
-#ifdef CONFIG_KALLSYMS
- /* symbol and string tables for decoding later. */
- if (sechdrs[i].sh_type == SHT_SYMTAB || i == strindex)
- sechdrs[i].sh_flags |= SHF_ALLOC;
-#endif
#ifndef CONFIG_MODULE_UNLOAD
/* Don't load .exit sections */
if (strstr(secstrings+sechdrs[i].sh_name, ".exit"))
@@ -1197,6 +1097,14 @@ static struct module *load_module(void *
#endif
}

+#ifdef CONFIG_KALLSYMS
+ /* Keep symbol and string tables for decoding later. */
+ sechdrs[symindex].sh_flags |= SHF_ALLOC;
+ sechdrs[strindex].sh_flags |= SHF_ALLOC;
+#endif
+
+ modindex = find_sec(hdr, sechdrs, secstrings,
+ ".gnu.linkonce.this_module");
if (!modindex) {
printk(KERN_WARNING "No module found in object\n");
err = -ENOEXEC;
@@ -1204,6 +1112,18 @@ static struct module *load_module(void *
}
mod = (void *)sechdrs[modindex].sh_addr;

+ /* Optional sections */
+ exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab");
+ gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl");
+ crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab");
+ gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl");
+ setupindex = find_sec(hdr, sechdrs, secstrings, "__param");
+ exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table");
+ obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm");
+ licenseindex = find_sec(hdr, sechdrs, secstrings, ".init.license");
+ vmagindex = find_sec(hdr, sechdrs, secstrings, "__vermagic");
+ versindex = find_sec(hdr, sechdrs, secstrings, "__versions");
+
/* Check module struct version now, before we try to use module. */
if (!check_modstruct_version(sechdrs, versindex, mod)) {
err = -ENOEXEC;
@@ -1336,10 +1256,14 @@ static struct module *load_module(void *
mod->extable.entry = (void *)sechdrs[exindex].sh_addr;
}

- /* Now handle each section. */
+ /* Now do relocations. */
for (i = 1; i < hdr->e_shnum; i++) {
- err = handle_section(secstrings + sechdrs[i].sh_name,
- sechdrs, strindex, symindex, i, mod);
+ if (sechdrs[i].sh_type == SHT_REL)
+ err = apply_relocate(sechdrs, strtab, symindex, i,
+ mod);
+ else if (sechdrs[i].sh_type == SHT_RELA)
+ err = apply_relocate_add(sechdrs, strtab, symindex, i,
+ mod);
if (err < 0)
goto cleanup;
}
--
Anyone who quotes me in their sig is an idiot. -- Rusty Russell.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:33    [W:0.024 / U:1.972 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site