[PATCH v2 1/2] refactor code parsing size based on memory range
From: Hari Bathini
Date: Wed Jun 22 2016 - 15:26:36 EST
Currently, crashkernel parameter supports the below syntax to parse size
based on memory range:
crashkernel=<range1>:<size1>[,<range2>:<size2>,...]
While such parsing is implemented for crashkernel parameter, it applies to
other parameters with similar syntax. So, move this code to a more generic
place for code reuse.
Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx>
Cc: Vivek Goyal <vgoyal@xxxxxxxxxx>
Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
Cc: kexec@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Hari Bathini <hbathini@xxxxxxxxxxxxxxxxxx>
---
changes in v2:
1. Rebased to latest upstream.
2. Marked few more people on cc.
include/linux/kernel.h | 5 +++
kernel/kexec_core.c | 63 +++-----------------------------
kernel/params.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 106 insertions(+), 58 deletions(-)
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 94aa10f..72f55e5 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -436,6 +436,11 @@ extern char *get_options(const char *str, int nints, int *ints);
extern unsigned long long memparse(const char *ptr, char **retptr);
extern bool parse_option_str(const char *str, const char *option);
+extern bool __init is_param_range_based(const char *cmdline);
+extern unsigned long long __init parse_mem_range_size(const char *param,
+ char **str,
+ unsigned long long system_ram);
+
extern int core_kernel_text(unsigned long addr);
extern int core_kernel_data(unsigned long addr);
extern int __kernel_text_address(unsigned long addr);
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index 56b3ed0..d43f5cc 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -1083,59 +1083,9 @@ static int __init parse_crashkernel_mem(char *cmdline,
char *cur = cmdline, *tmp;
/* for each entry of the comma-separated list */
- do {
- unsigned long long start, end = ULLONG_MAX, size;
-
- /* get the start of the range */
- start = memparse(cur, &tmp);
- if (cur == tmp) {
- pr_warn("crashkernel: Memory value expected\n");
- return -EINVAL;
- }
- cur = tmp;
- if (*cur != '-') {
- pr_warn("crashkernel: '-' expected\n");
- return -EINVAL;
- }
- cur++;
-
- /* if no ':' is here, than we read the end */
- if (*cur != ':') {
- end = memparse(cur, &tmp);
- if (cur == tmp) {
- pr_warn("crashkernel: Memory value expected\n");
- return -EINVAL;
- }
- cur = tmp;
- if (end <= start) {
- pr_warn("crashkernel: end <= start\n");
- return -EINVAL;
- }
- }
-
- if (*cur != ':') {
- pr_warn("crashkernel: ':' expected\n");
- return -EINVAL;
- }
- cur++;
-
- size = memparse(cur, &tmp);
- if (cur == tmp) {
- pr_warn("Memory value expected\n");
- return -EINVAL;
- }
- cur = tmp;
- if (size >= system_ram) {
- pr_warn("crashkernel: invalid size\n");
- return -EINVAL;
- }
-
- /* match ? */
- if (system_ram >= start && system_ram < end) {
- *crash_size = size;
- break;
- }
- } while (*cur++ == ',');
+ *crash_size = parse_mem_range_size("crashkernel", &cur, system_ram);
+ if (cur == cmdline)
+ return -EINVAL;
if (*crash_size > 0) {
while (*cur && *cur != ' ' && *cur != '@')
@@ -1272,7 +1222,6 @@ static int __init __parse_crashkernel(char *cmdline,
const char *name,
const char *suffix)
{
- char *first_colon, *first_space;
char *ck_cmdline;
BUG_ON(!crash_size || !crash_base);
@@ -1290,12 +1239,10 @@ static int __init __parse_crashkernel(char *cmdline,
return parse_crashkernel_suffix(ck_cmdline, crash_size,
suffix);
/*
- * if the commandline contains a ':', then that's the extended
+ * if the parameter is range based, then that's the extended
* syntax -- if not, it must be the classic syntax
*/
- first_colon = strchr(ck_cmdline, ':');
- first_space = strchr(ck_cmdline, ' ');
- if (first_colon && (!first_space || first_colon < first_space))
+ if (is_param_range_based(ck_cmdline))
return parse_crashkernel_mem(ck_cmdline, system_ram,
crash_size, crash_base);
diff --git a/kernel/params.c b/kernel/params.c
index a6d6149..84e40ae 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -268,6 +268,102 @@ char *parse_args(const char *doing,
return err;
}
+/*
+ * is_param_range_based - check if current parameter is range based
+ * @cmdline: points to the parameter to check
+ *
+ * Returns true when the current paramer is range based, false otherwise
+ */
+bool __init is_param_range_based(const char *cmdline)
+{
+ char *first_colon, *first_space;
+
+ first_colon = strchr(cmdline, ':');
+ first_space = strchr(cmdline, ' ');
+ if (first_colon && (!first_space || first_colon < first_space))
+ return true;
+
+ return false;
+}
+
+/*
+ * parse_mem_range_size - parse size based on memory range
+ * @param: the thing being parsed
+ * @str: (input) where parse begins
+ * expected format - <range1>:<size1>[,<range2>:<size2>,...]
+ * (output) On success - next char after parse completes
+ * On failure - unchanged
+ * @system_ram: system ram size to check memory range against
+ *
+ * Returns the memory size on success and 0 on failure
+ */
+unsigned long long __init parse_mem_range_size(const char *param,
+ char **str,
+ unsigned long long system_ram)
+{
+ char *cur = *str, *tmp;
+ unsigned long long mem_size = 0;
+
+ /* for each entry of the comma-separated list */
+ do {
+ unsigned long long start, end = ULLONG_MAX, size;
+
+ /* get the start of the range */
+ start = memparse(cur, &tmp);
+ if (cur == tmp) {
+ printk(KERN_INFO "%s: Memory value expected\n", param);
+ return mem_size;
+ }
+ cur = tmp;
+ if (*cur != '-') {
+ printk(KERN_INFO "%s: '-' expected\n", param);
+ return mem_size;
+ }
+ cur++;
+
+ /* if no ':' is here, than we read the end */
+ if (*cur != ':') {
+ end = memparse(cur, &tmp);
+ if (cur == tmp) {
+ printk(KERN_INFO "%s: Memory value expected\n",
+ param);
+ return mem_size;
+ }
+ cur = tmp;
+ if (end <= start) {
+ printk(KERN_INFO "%s: end <= start\n", param);
+ return mem_size;
+ }
+ }
+
+ if (*cur != ':') {
+ printk(KERN_INFO "%s: ':' expected\n", param);
+ return mem_size;
+ }
+ cur++;
+
+ size = memparse(cur, &tmp);
+ if (cur == tmp) {
+ printk(KERN_INFO "%s: Memory value expected\n", param);
+ return mem_size;
+ }
+ cur = tmp;
+ if (size >= system_ram) {
+ printk(KERN_INFO "%s: invalid size\n", param);
+ return mem_size;
+ }
+
+ /* match ? */
+ if (system_ram >= start && system_ram < end) {
+ mem_size = size;
+ *str = cur;
+ break;
+ }
+ } while (*cur++ == ',');
+
+ return mem_size;
+}
+
/* Lazy bastard, eh? */
#define STANDARD_PARAM_DEF(name, type, format, strtolfn) \
int param_set_##name(const char *val, const struct kernel_param *kp) \