[patch 01/14] Modules: Handle symbols that have a zero value

Christoph Lameter
2007-11-27T00:14:55Z

[-- Attachment #1: weaky --]
[-- Type: text/plain, Size: 2630 bytes --]

The module subsystem cannot handle symbols that are zero. If symbols are
present that have a zero value then the module resolver prints out
a message that these symbols are unresolved.

[patch already in mm]

Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Christoph Lameter <clameter@sgi.com>

---
kernel/module.c | 17 ++++++++++-------
1 file changed, 10 insertions(+), 7 deletions(-)

Index: linux-2.6/kernel/module.c
===================================================================
--- linux-2.6.orig/kernel/module.c 2007-11-21 12:58:33.095608448 -0800
+++ linux-2.6/kernel/module.c 2007-11-21 13:00:30.199108674 -0800
@@ -285,7 +285,7 @@ static unsigned long __find_symbol(const
}
}
DEBUGP("Failed to find symbol %s\n", name);
- return 0;
+ return -ENOENT;
}

/* Search for module by name: must hold module_mutex. */
@@ -756,7 +756,7 @@ void __symbol_put(const char *symbol)
const unsigned long *crc;

preempt_disable();
- if (!__find_symbol(symbol, &owner, &crc, 1))
+ if (IS_ERR_VALUE(__find_symbol(symbol, &owner, &crc, 1)))
BUG();
module_put(owner);
preempt_enable();
@@ -902,7 +902,8 @@ static inline int check_modstruct_versio
const unsigned long *crc;
struct module *owner;

- if (!__find_symbol("struct_module", &owner, &crc, 1))
+ if (IS_ERR_VALUE(__find_symbol("struct_module",
+ &owner, &crc, 1)))
BUG();
return check_version(sechdrs, versindex, "struct_module", mod,
crc);
@@ -955,7 +956,7 @@ static unsigned long resolve_symbol(Elf_
/* use_module can fail due to OOM, or module unloading */
if (!check_version(sechdrs, versindex, name, mod, crc) ||
!use_module(mod, owner))
- ret = 0;
+ ret = -EINVAL;
}
return ret;
}
@@ -1348,14 +1349,16 @@ static int verify_export_symbols(struct
const unsigned long *crc;

for (i = 0; i < mod->num_syms; i++)
- if (__find_symbol(mod->syms[i].name, &owner, &crc, 1)) {
+ if (!IS_ERR_VALUE(__find_symbol(mod->syms[i].name,
+ &owner, &crc, 1))) {
name = mod->syms[i].name;
ret = -ENOEXEC;
goto dup;
}

for (i = 0; i < mod->num_gpl_syms; i++)
- if (__find_symbol(mod->gpl_syms[i].name, &owner, &crc, 1)) {
+ if (!IS_ERR_VALUE(__find_symbol(mod->gpl_syms[i].name,
+ &owner, &crc, 1))) {
name = mod->gpl_syms[i].name;
ret = -ENOEXEC;
goto dup;
@@ -1405,7 +1408,7 @@ static int simplify_symbols(Elf_Shdr *se
strtab + sym[i].st_name, mod);

/* Ok if resolved. */
- if (sym[i].st_value != 0)
+ if (!IS_ERR_VALUE(sym[i].st_value))
break;
/* Ok if weak. */
if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)

--