[PATCH v8 5/6] boot/param: add pointer to current and next argument to unknown parameter callback

From: Michal Suchanek
Date: Tue Sep 12 2017 - 12:02:52 EST

The fadump parameter processing re-does the logic of next_arg quote
stripping to determine where the argument ends. Pass pointer to the
current and next argument instead to make this more robust.

Signed-off-by: Michal Suchanek <msuchanek@xxxxxxx>
---
rebase on master
split off changes to fadump.c
add pointer to current argument to detect shortening of the parameterer name
---
arch/powerpc/kernel/fadump.c | 1 +
include/linux/moduleparam.h | 1 +
init/main.c | 8 ++++++--
kernel/module.c | 5 +++--
kernel/params.c | 20 +++++++++++++-------
lib/dynamic_debug.c | 1 +
6 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index b214c1e333dd..8778e1cc0380 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -541,6 +541,7 @@ static void __init fadump_update_params(struct param_info *param_info,
* to enforce the parameters passed through it
*/
static int __init fadump_rework_cmdline_params(char *param, char *val,
+ char *currant, char *next,
const char *unused, void *arg)
{
struct param_info *param_info = (struct param_info *)arg;
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index 1ee7b30dafec..e86f3f830a7f 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -327,6 +327,7 @@ extern char *parse_args(const char *name,
s16 level_max,
void *arg,
int (*unknown)(char *param, char *val,
+ char *currant, char *next,
const char *doing, void *arg));

/* Called by module remove. */
diff --git a/init/main.c b/init/main.c
index 0ee9c6866ada..9381aa24bca7 100644
--- a/init/main.c
+++ b/init/main.c
@@ -240,6 +240,7 @@ early_param("loglevel", loglevel);

/* Change NUL term back to "=", to make "param" the whole string. */
static int __init repair_env_string(char *param, char *val,
+ char *unused3, char *unused2,
const char *unused, void *arg)
{
if (val) {
@@ -258,6 +259,7 @@ static int __init repair_env_string(char *param, char *val,

/* Anything after -- gets handed straight to init. */
static int __init set_init_arg(char *param, char *val,
+ char *unused3, char *unused2,
const char *unused, void *arg)
{
unsigned int i;
@@ -265,7 +267,7 @@ static int __init set_init_arg(char *param, char *val,
if (panic_later)
return 0;

- repair_env_string(param, val, unused, NULL);
+ repair_env_string(param, val, unused3, unused2, unused, NULL);

for (i = 0; argv_init[i]; i++) {
if (i == MAX_INIT_ARGS) {
@@ -283,9 +285,10 @@ static int __init set_init_arg(char *param, char *val,
* unused parameters (modprobe will find them in /proc/cmdline).
*/
static int __init unknown_bootoption(char *param, char *val,
+ char *unused3, char *unused2,
const char *unused, void *arg)
{
- repair_env_string(param, val, unused, NULL);
+ repair_env_string(param, val, unused3, unused2, unused, NULL);

/* Handle obsolete-style parameters */
if (obsolete_checksetup(param))
@@ -437,6 +440,7 @@ static noinline void __ref rest_init(void)

/* Check for early params. */
static int __init do_early_param(char *param, char *val,
+ char *unused3, char *unused2,
const char *unused, void *arg)
{
const struct obs_kernel_param *p;
diff --git a/kernel/module.c b/kernel/module.c
index 40f983cbea81..0f74718f8934 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -3609,8 +3609,9 @@ static int prepare_coming_module(struct module *mod)
return 0;
}

-static int unknown_module_param_cb(char *param, char *val, const char *modname,
- void *arg)
+static int unknown_module_param_cb(char *param, char *val,
+ char *unused, char *unused2,
+ const char *modname, void *arg)
{
struct module *mod = arg;
int ret;
diff --git a/kernel/params.c b/kernel/params.c
index 60b2d8101355..c0e0c65f460b 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -119,6 +119,8 @@ static void param_check_unsafe(const struct kernel_param *kp)

static int parse_one(char *param,
char *val,
+ char *currant,
+ char *next,
const char *doing,
const struct kernel_param *params,
unsigned num_params,
@@ -126,7 +128,8 @@ static int parse_one(char *param,
s16 max_level,
void *arg,
int (*handle_unknown)(char *param, char *val,
- const char *doing, void *arg))
+ char *currant, char *next,
+ const char *doing, void *arg))
{
unsigned int i;
int err;
@@ -153,7 +156,7 @@ static int parse_one(char *param,

if (handle_unknown) {
pr_debug("doing %s: %s='%s'\n", doing, param, val);
- return handle_unknown(param, val, doing, arg);
+ return handle_unknown(param, val, currant, next, doing, arg);
}

pr_debug("Unknown argument '%s'\n", param);
@@ -169,9 +172,10 @@ char *parse_args(const char *doing,
s16 max_level,
void *arg,
int (*unknown)(char *param, char *val,
+ char *currant, char *next,
const char *doing, void *arg))
{
- char *param, *val, *err = NULL;
+ char *param, *val, *next, *err = NULL;

/* Chew leading spaces */
args = skip_spaces(args);
@@ -179,16 +183,18 @@ char *parse_args(const char *doing,
if (*args)
pr_debug("doing %s, parsing ARGS: '%s'\n", doing, args);

- while (*args) {
+ next = next_arg(args, &param, &val);
+ do {
int ret;
int irq_was_disabled;

- args = next_arg(args, &param, &val);
+ args = next;
+ next = next_arg(args, &param, &val);
/* Stop at -- */
if (!val && strcmp(param, "--") == 0)
return err ?: args;
irq_was_disabled = irqs_disabled();
- ret = parse_one(param, val, doing, params, num,
+ ret = parse_one(param, val, args, next, doing, params, num,
min_level, max_level, arg, unknown);
if (irq_was_disabled && !irqs_disabled())
pr_warn("%s: option '%s' enabled irq's!\n",
@@ -211,7 +217,7 @@ char *parse_args(const char *doing,
}

err = ERR_PTR(ret);
- }
+ } while (*next);

return err;
}
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index da796e2dc4f5..dec7f40c3f47 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -889,6 +889,7 @@ static int ddebug_dyndbg_param_cb(char *param, char *val,

/* handle both dyndbg and $module.dyndbg params at boot */
static int ddebug_dyndbg_boot_param_cb(char *param, char *val,
+ char *unused3, char *unused2,
const char *unused, void *arg)
{
vpr_info("%s=\"%s\"\n", param, val);
--
2.10.2