mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-08-31 08:15:07 -04:00
Code Issues Packages Projects Releases Wiki Activity

binfmt_misc: turn the entry bit numbers into a proper enum

Browse Source 
Enabled and Magic are bit numbers in the flags word of an entry but
are declared as bare, unprefixed enumerators with implicit values in
a style that predates the git history. Give the enum a name, explicit
bit numbers and namespaced names and use BIT() instead of open-coding
the shifts when building the initial flags word in create_entry().

No functional change.

Link: https://patch.msgid.link/20260710-work-binfmt_misc-locking-v3-7-a162f7cb58d6@kernel.org
Reviewed-by: Jori Koolstra <jkoolstra@xs4all.nl>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
This commit is contained in:
Christian Brauner
2026-07-10 11:33:08 +02:00
parent 1dc88208cf
commit c9fa1f1ccf
1 changed files with 14 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

24
fs/binfmt_misc.c
View File

@@ -42,7 +42,11 @@ enum {
VERBOSE_STATUS = 1 /* make it zero to save 400 bytes kernel memory */
};
enum {Enabled, Magic};
/* Entry status and match type bit numbers. */
enum binfmt_misc_entry_bits {
MISC_FMT_ENABLED_BIT = 0,
MISC_FMT_MAGIC_BIT = 1,
};
#define MISC_FMT_PRESERVE_ARGV0 (1UL << 31)
#define MISC_FMT_OPEN_BINARY (1UL << 30)
#define MISC_FMT_CREDENTIALS (1UL << 29)
@@ -104,11 +108,11 @@ static Node *search_binfmt_handler(struct binfmt_misc *misc,
int j;
/* Make sure this one is currently enabled. */
if (!test_bit(Enabled, &e->flags))
if (!test_bit(MISC_FMT_ENABLED_BIT, &e->flags))
continue;
/* Do matching based on extension if applicable. */
if (!test_bit(Magic, &e->flags)) {
if (!test_bit(MISC_FMT_MAGIC_BIT, &e->flags)) {
if (p && !strcmp(e->magic, p + 1))
return e;
continue;
@@ -416,11 +420,11 @@ static Node *create_entry(const char __user *buffer, size_t count)
switch (*p++) {
case 'E':
pr_debug("register: type: E (extension)\n");
e->flags = 1 << Enabled;
e->flags = BIT(MISC_FMT_ENABLED_BIT);
break;
case 'M':
pr_debug("register: type: M (magic)\n");
e->flags = (1 << Enabled) | (1 << Magic);
e->flags = BIT(MISC_FMT_ENABLED_BIT) | BIT(MISC_FMT_MAGIC_BIT);
break;
default:
goto einval;
@@ -428,7 +432,7 @@ static Node *create_entry(const char __user *buffer, size_t count)
if (*p++ != del)
goto einval;
if (test_bit(Magic, &e->flags)) {
if (test_bit(MISC_FMT_MAGIC_BIT, &e->flags)) {
/* Handle the 'M' (magic) format. */
char *s;
@@ -598,7 +602,7 @@ static void entry_status(Node *e, char *page)
char *dp = page;
const char *status = "disabled";
if (test_bit(Enabled, &e->flags))
if (test_bit(MISC_FMT_ENABLED_BIT, &e->flags))
status = "enabled";
if (!VERBOSE_STATUS) {
@@ -620,7 +624,7 @@ static void entry_status(Node *e, char *page)
*dp++ = 'F';
*dp++ = '\n';
if (!test_bit(Magic, &e->flags)) {
if (!test_bit(MISC_FMT_MAGIC_BIT, &e->flags)) {
sprintf(dp, "extension .%s\n", e->magic);
} else {
dp += sprintf(dp, "offset %i\nmagic ", e->offset);
@@ -744,11 +748,11 @@ static ssize_t bm_entry_write(struct file *file, const char __user *buffer,
switch (res) {
case 1:
/* Disable this handler. */
clear_bit(Enabled, &e->flags);
clear_bit(MISC_FMT_ENABLED_BIT, &e->flags);
break;
case 2:
/* Enable this handler. */
set_bit(Enabled, &e->flags);
set_bit(MISC_FMT_ENABLED_BIT, &e->flags);
break;
case 3:
/* Delete this handler. */