[PATCH 3.12 140/142] module: wrapper for symbol name.

From: Jiri Slaby
Date: Wed Feb 24 2016 - 05:09:36 EST


From: Rusty Russell <rusty@xxxxxxxxxxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit 2e7bac536106236104e9e339531ff0fcdb7b8147 upstream.

This trivial wrapper adds clarity and makes the following patch
smaller.

Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
kernel/module.c | 26 +++++++++++++++-----------
1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/kernel/module.c b/kernel/module.c
index 7d1c2ea27898..cb56e581062d 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3425,6 +3425,11 @@ static inline int is_arm_mapping_symbol(const char *str)
&& (str[2] == '\0' || str[2] == '.');
}

+static const char *symname(struct module *mod, unsigned int symnum)
+{
+ return mod->strtab + mod->symtab[symnum].st_name;
+}
+
static const char *get_ksymbol(struct module *mod,
unsigned long addr,
unsigned long *size,
@@ -3447,15 +3452,15 @@ static const char *get_ksymbol(struct module *mod,

/* We ignore unnamed symbols: they're uninformative
* and inserted at a whim. */
+ if (*symname(mod, i) == '\0'
+ || is_arm_mapping_symbol(symname(mod, i)))
+ continue;
+
if (mod->symtab[i].st_value <= addr
- && mod->symtab[i].st_value > mod->symtab[best].st_value
- && *(mod->strtab + mod->symtab[i].st_name) != '\0'
- && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
+ && mod->symtab[i].st_value > mod->symtab[best].st_value)
best = i;
if (mod->symtab[i].st_value > addr
- && mod->symtab[i].st_value < nextval
- && *(mod->strtab + mod->symtab[i].st_name) != '\0'
- && !is_arm_mapping_symbol(mod->strtab + mod->symtab[i].st_name))
+ && mod->symtab[i].st_value < nextval)
nextval = mod->symtab[i].st_value;
}

@@ -3466,7 +3471,7 @@ static const char *get_ksymbol(struct module *mod,
*size = nextval - mod->symtab[best].st_value;
if (offset)
*offset = addr - mod->symtab[best].st_value;
- return mod->strtab + mod->symtab[best].st_name;
+ return symname(mod, best);
}

/* For kallsyms to ask for address resolution. NULL means not found. Careful
@@ -3567,8 +3572,7 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
if (symnum < mod->num_symtab) {
*value = mod->symtab[symnum].st_value;
*type = mod->symtab[symnum].st_info;
- strlcpy(name, mod->strtab + mod->symtab[symnum].st_name,
- KSYM_NAME_LEN);
+ strlcpy(name, symname(mod, symnum), KSYM_NAME_LEN);
strlcpy(module_name, mod->name, MODULE_NAME_LEN);
*exported = is_exported(name, *value, mod);
preempt_enable();
@@ -3585,7 +3589,7 @@ static unsigned long mod_find_symname(struct module *mod, const char *name)
unsigned int i;

for (i = 0; i < mod->num_symtab; i++)
- if (strcmp(name, mod->strtab+mod->symtab[i].st_name) == 0 &&
+ if (strcmp(name, symname(mod, i)) == 0 &&
mod->symtab[i].st_info != 'U')
return mod->symtab[i].st_value;
return 0;
@@ -3627,7 +3631,7 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *,
if (mod->state == MODULE_STATE_UNFORMED)
continue;
for (i = 0; i < mod->num_symtab; i++) {
- ret = fn(data, mod->strtab + mod->symtab[i].st_name,
+ ret = fn(data, symname(mod, i),
mod, mod->symtab[i].st_value);
if (ret != 0)
return ret;
--
2.7.1