* [PATCH v2 1/2] module: Fix ERRORs reported by checkpatch.pl
@ 2022-06-13 6:02 Christophe Leroy
2022-06-13 6:02 ` [PATCH v2 2/2] module: Increase readability of module_kallsyms_lookup_name() Christophe Leroy
0 siblings, 1 reply; 3+ messages in thread
From: Christophe Leroy @ 2022-06-13 6:02 UTC (permalink / raw)
To: Luis Chamberlain, linux-modules; +Cc: Christophe Leroy, linux-kernel
Checkpatch reports following errors:
ERROR: do not use assignment in if condition
+ if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
ERROR: do not use assignment in if condition
+ if ((mod = find_module_all(name, colon - name, false)) != NULL)
ERROR: do not use assignment in if condition
+ if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
ERROR: do not initialise globals to 0
+int modules_disabled = 0;
Fix them.
The following one has to remain, because the condition has to be evaluated
multiple times by the macro wait_event_interruptible_timeout().
ERROR: do not use assignment in if condition
+ if (wait_event_interruptible_timeout(module_wq,
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
v2: Drop the last change
---
kernel/module/kallsyms.c | 9 ++++++---
kernel/module/main.c | 2 +-
2 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c
index 3e11523bc6f6..fe3636bde605 100644
--- a/kernel/module/kallsyms.c
+++ b/kernel/module/kallsyms.c
@@ -457,14 +457,17 @@ unsigned long module_kallsyms_lookup_name(const char *name)
/* Don't lock: we're in enough trouble already. */
preempt_disable();
- if ((colon = strnchr(name, MODULE_NAME_LEN, ':')) != NULL) {
- if ((mod = find_module_all(name, colon - name, false)) != NULL)
+ colon = strnchr(name, MODULE_NAME_LEN, ':');
+ if (colon) {
+ mod = find_module_all(name, colon - name, false);
+ if (mod)
ret = find_kallsyms_symbol_value(mod, colon + 1);
} else {
list_for_each_entry_rcu(mod, &modules, list) {
if (mod->state == MODULE_STATE_UNFORMED)
continue;
- if ((ret = find_kallsyms_symbol_value(mod, name)) != 0)
+ ret = find_kallsyms_symbol_value(mod, name);
+ if (ret)
break;
}
}
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 0548151dd933..b37e25676615 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -119,7 +119,7 @@ static void mod_update_bounds(struct module *mod)
}
/* Block module loading/unloading? */
-int modules_disabled = 0;
+int modules_disabled;
core_param(nomodule, modules_disabled, bint, 0);
/* Waiting for a module to finish initializing? */
--
2.35.3
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH v2 2/2] module: Increase readability of module_kallsyms_lookup_name()
2022-06-13 6:02 [PATCH v2 1/2] module: Fix ERRORs reported by checkpatch.pl Christophe Leroy
@ 2022-06-13 6:02 ` Christophe Leroy
2022-07-01 22:07 ` Luis Chamberlain
0 siblings, 1 reply; 3+ messages in thread
From: Christophe Leroy @ 2022-06-13 6:02 UTC (permalink / raw)
To: Luis Chamberlain, linux-modules; +Cc: Christophe Leroy, linux-kernel
module_kallsyms_lookup_name() has several exit conditions but
can't return immediately due to preempt_disable().
Refactor module_kallsyms_lookup_name() to allow returning from
anywhere, and reduce depth.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
kernel/module/kallsyms.c | 38 ++++++++++++++++++++++++--------------
1 file changed, 24 insertions(+), 14 deletions(-)
diff --git a/kernel/module/kallsyms.c b/kernel/module/kallsyms.c
index fe3636bde605..df0150c467d4 100644
--- a/kernel/module/kallsyms.c
+++ b/kernel/module/kallsyms.c
@@ -448,29 +448,39 @@ unsigned long find_kallsyms_symbol_value(struct module *mod, const char *name)
return 0;
}
-/* Look for this name: can be of form module:name. */
-unsigned long module_kallsyms_lookup_name(const char *name)
+static unsigned long __module_kallsyms_lookup_name(const char *name)
{
struct module *mod;
char *colon;
- unsigned long ret = 0;
- /* Don't lock: we're in enough trouble already. */
- preempt_disable();
colon = strnchr(name, MODULE_NAME_LEN, ':');
if (colon) {
mod = find_module_all(name, colon - name, false);
if (mod)
- ret = find_kallsyms_symbol_value(mod, colon + 1);
- } else {
- list_for_each_entry_rcu(mod, &modules, list) {
- if (mod->state == MODULE_STATE_UNFORMED)
- continue;
- ret = find_kallsyms_symbol_value(mod, name);
- if (ret)
- break;
- }
+ return find_kallsyms_symbol_value(mod, colon + 1);
+ return 0;
}
+
+ list_for_each_entry_rcu(mod, &modules, list) {
+ unsigned long ret;
+
+ if (mod->state == MODULE_STATE_UNFORMED)
+ continue;
+ ret = find_kallsyms_symbol_value(mod, name);
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
+/* Look for this name: can be of form module:name. */
+unsigned long module_kallsyms_lookup_name(const char *name)
+{
+ unsigned long ret;
+
+ /* Don't lock: we're in enough trouble already. */
+ preempt_disable();
+ ret = __module_kallsyms_lookup_name(name);
preempt_enable();
return ret;
}
--
2.35.3
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2 2/2] module: Increase readability of module_kallsyms_lookup_name()
2022-06-13 6:02 ` [PATCH v2 2/2] module: Increase readability of module_kallsyms_lookup_name() Christophe Leroy
@ 2022-07-01 22:07 ` Luis Chamberlain
0 siblings, 0 replies; 3+ messages in thread
From: Luis Chamberlain @ 2022-07-01 22:07 UTC (permalink / raw)
To: Christophe Leroy; +Cc: linux-modules, linux-kernel
On Mon, Jun 13, 2022 at 08:02:02AM +0200, Christophe Leroy wrote:
> module_kallsyms_lookup_name() has several exit conditions but
> can't return immediately due to preempt_disable().
>
> Refactor module_kallsyms_lookup_name() to allow returning from
> anywhere, and reduce depth.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Thanks for this cleanup, holy crap that was gross before, queued up!
Luis
^ permalink raw reply [flat|nested] 3+ messages in thread
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2022-06-13 6:02 [PATCH v2 1/2] module: Fix ERRORs reported by checkpatch.pl Christophe Leroy
2022-06-13 6:02 ` [PATCH v2 2/2] module: Increase readability of module_kallsyms_lookup_name() Christophe Leroy
2022-07-01 22:07 ` Luis Chamberlain
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