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| author | Tim Abbott <tabbott@MIT.EDU> | 2009-01-05 08:40:10 -0600 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2009-01-05 08:40:11 +1030 |
| commit | ca4787b779dd698a2a33a328aa5fa90a3e954077 (patch) | |
| tree | 678eddc5cfd0b366b1ef5662cf6ccdd7b7b2f135 | |
| parent | a327ca2c2674c5a9a0073421df19bfc362698136 (diff) | |
| download | linux-ca4787b779dd698a2a33a328aa5fa90a3e954077.tar.gz | |
kernel/module.c: compare symbol values when marking symbols as exported in /proc/kallsyms.
When there are two symbols in a module with the same name, one of which is exported, both will be marked as exported in /proc/kallsyms. There aren't any instances of this in the current kernel, but it is easy to construct a simple module with two compilation units that exhibits the problem. $ objdump -j .text -t testmod.ko | grep foo 00000000 l F .text 00000032 foo 00000080 g F .text 00000001 foo $ sudo insmod testmod.ko $ grep "T foo" /proc/kallsyms c28e8000 T foo [testmod] c28e8080 T foo [testmod] Fix this by comparing the symbol values once we've found the exported symbol table entry matching the symbol name. Tested using Ksplice: $ ksplice-create --patch=this_commit.patch --id=bar . $ sudo ksplice-apply ksplice-bar.tar.gz Done! $ grep "T foo" /proc/kallsyms c28e8080 T foo [testmod] Signed-off-by: Tim Abbott <tabbott@mit.edu> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| -rw-r--r-- | kernel/module.c | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/kernel/module.c b/kernel/module.c index dd2a54155b54..895c5675edb7 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1725,15 +1725,15 @@ static const struct kernel_symbol *lookup_symbol(const char *name, return NULL; } -static int is_exported(const char *name, const struct module *mod) +static int is_exported(const char *name, unsigned long value, + const struct module *mod) { - if (!mod && lookup_symbol(name, __start___ksymtab, __stop___ksymtab)) - return 1; + const struct kernel_symbol *ks; + if (!mod) + ks = lookup_symbol(name, __start___ksymtab, __stop___ksymtab); else - if (mod && lookup_symbol(name, mod->syms, mod->syms + mod->num_syms)) - return 1; - else - return 0; + ks = lookup_symbol(name, mod->syms, mod->syms + mod->num_syms); + return ks != NULL && ks->value == value; } /* As per nm */ @@ -2504,7 +2504,7 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, strlcpy(name, mod->strtab + mod->symtab[symnum].st_name, KSYM_NAME_LEN); strlcpy(module_name, mod->name, MODULE_NAME_LEN); - *exported = is_exported(name, mod); + *exported = is_exported(name, *value, mod); preempt_enable(); return 0; } |