summaryrefslogtreecommitdiffstats
path: root/arch/x86/lib/cmdline.c
diff options
context:
space:
mode:
authorKees Cook <kees+treewide@kernel.org>2026-09-02 15:31:14 -0700
committerKees Cook <kees@kernel.org>2026-09-04 21:37:00 -0700
commit3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d (patch)
treec65086f9bdcd48c6360fb7cb4598bca084da1f32 /arch/x86/lib/cmdline.c
downloadlinux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.tar.gz
linux-stable-3a2c4d55e32ad65efebdb6de44eef3bfa08bb49d.zip
treewide: refresh kmalloc_obj() conversionsgrafted
This is another run of the Coccinelle script for converting kmalloc() family of allocations to kmalloc_obj() via the existing rules in scripts/coccinelle/api/kmalloc_objs.cocci This catches both the set of kmalloc() uses added since the first kmalloc_obj() conversions in v7.0 and adds a large group missed in the first pass due to Coccinelle not interacting well with the cleanup.h scoped_...() family of macros[1]. I worked around this with spatch's "--macro-file" argument to a file with all the scoped_...() macros mapped to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control flow indicator I could find. Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc, riscv, and s390 with no new warnings. Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1] Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2] Signed-off-by: Kees Cook <kees+treewide@kernel.org>
Diffstat (limited to 'arch/x86/lib/cmdline.c')
-rw-r--r--arch/x86/lib/cmdline.c235
1 files changed, 235 insertions, 0 deletions
diff --git a/arch/x86/lib/cmdline.c b/arch/x86/lib/cmdline.c
new file mode 100644
index 000000000..c65cd5550
--- /dev/null
+++ b/arch/x86/lib/cmdline.c
@@ -0,0 +1,235 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *
+ * Misc librarized functions for cmdline poking.
+ */
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+
+#include <asm/setup.h>
+#include <asm/cmdline.h>
+#include <asm/bug.h>
+
+static inline int myisspace(u8 c)
+{
+ return c <= ' '; /* Close enough approximation */
+}
+
+/*
+ * Find a boolean option (like quiet,noapic,nosmp....)
+ *
+ * @cmdline: the cmdline string
+ * @max_cmdline_size: the maximum size of cmdline
+ * @option: option string to look for
+ *
+ * Returns the position of that @option (starts counting with 1)
+ * or 0 on not found. @option will only be found if it is found
+ * as an entire word in @cmdline. For instance, if @option="car"
+ * then a cmdline which contains "cart" will not match.
+ */
+static int
+__cmdline_find_option_bool(const char *cmdline, int max_cmdline_size,
+ const char *option)
+{
+ char c;
+ int pos = 0, wstart = 0;
+ const char *opptr = NULL;
+ enum {
+ st_wordstart = 0, /* Start of word/after whitespace */
+ st_wordcmp, /* Comparing this word */
+ st_wordskip, /* Miscompare, skip */
+ } state = st_wordstart;
+
+ if (!cmdline)
+ return -1; /* No command line */
+
+ /*
+ * This 'pos' check ensures we do not overrun
+ * a non-NULL-terminated 'cmdline'
+ */
+ while (pos < max_cmdline_size) {
+ c = *(char *)cmdline++;
+ pos++;
+
+ switch (state) {
+ case st_wordstart:
+ if (!c)
+ return 0;
+ else if (myisspace(c))
+ break;
+
+ state = st_wordcmp;
+ opptr = option;
+ wstart = pos;
+ fallthrough;
+
+ case st_wordcmp:
+ if (!*opptr) {
+ /*
+ * We matched all the way to the end of the
+ * option we were looking for. If the
+ * command-line has a space _or_ ends, then
+ * we matched!
+ */
+ if (!c || myisspace(c))
+ return wstart;
+ /*
+ * We hit the end of the option, but _not_
+ * the end of a word on the cmdline. Not
+ * a match.
+ */
+ } else if (!c) {
+ /*
+ * Hit the NULL terminator on the end of
+ * cmdline.
+ */
+ return 0;
+ } else if (c == *opptr++) {
+ /*
+ * We are currently matching, so continue
+ * to the next character on the cmdline.
+ */
+ break;
+ }
+ state = st_wordskip;
+ fallthrough;
+
+ case st_wordskip:
+ if (!c)
+ return 0;
+ else if (myisspace(c))
+ state = st_wordstart;
+ break;
+ }
+ }
+
+ return 0; /* Buffer overrun */
+}
+
+/*
+ * Find a non-boolean option (i.e. option=argument). In accordance with
+ * standard Linux practice, if this option is repeated, this returns the
+ * last instance on the command line.
+ *
+ * @cmdline: the cmdline string
+ * @max_cmdline_size: the maximum size of cmdline
+ * @option: option string to look for
+ * @buffer: memory buffer to return the option argument
+ * @bufsize: size of the supplied memory buffer
+ *
+ * Returns the length of the argument (regardless of if it was
+ * truncated to fit in the buffer), or -1 on not found.
+ */
+static int
+__cmdline_find_option(const char *cmdline, int max_cmdline_size,
+ const char *option, char *buffer, int bufsize)
+{
+ char c;
+ int pos = 0, len = -1;
+ const char *opptr = NULL;
+ char *bufptr = buffer;
+ enum {
+ st_wordstart = 0, /* Start of word/after whitespace */
+ st_wordcmp, /* Comparing this word */
+ st_wordskip, /* Miscompare, skip */
+ st_bufcpy, /* Copying this to buffer */
+ } state = st_wordstart;
+
+ if (!cmdline)
+ return -1; /* No command line */
+
+ /*
+ * This 'pos' check ensures we do not overrun
+ * a non-NULL-terminated 'cmdline'
+ */
+ while (pos++ < max_cmdline_size) {
+ c = *(char *)cmdline++;
+ if (!c)
+ break;
+
+ switch (state) {
+ case st_wordstart:
+ if (myisspace(c))
+ break;
+
+ state = st_wordcmp;
+ opptr = option;
+ fallthrough;
+
+ case st_wordcmp:
+ if ((c == '=') && !*opptr) {
+ /*
+ * We matched all the way to the end of the
+ * option we were looking for, prepare to
+ * copy the argument.
+ */
+ len = 0;
+ bufptr = buffer;
+ state = st_bufcpy;
+ break;
+ } else if (c == *opptr++) {
+ /*
+ * We are currently matching, so continue
+ * to the next character on the cmdline.
+ */
+ break;
+ }
+ state = st_wordskip;
+ fallthrough;
+
+ case st_wordskip:
+ if (myisspace(c))
+ state = st_wordstart;
+ break;
+
+ case st_bufcpy:
+ if (myisspace(c)) {
+ state = st_wordstart;
+ } else {
+ /*
+ * Increment len, but don't overrun the
+ * supplied buffer and leave room for the
+ * NULL terminator.
+ */
+ if (++len < bufsize)
+ *bufptr++ = c;
+ }
+ break;
+ }
+ }
+
+ if (bufsize)
+ *bufptr = '\0';
+
+ return len;
+}
+
+int cmdline_find_option_bool(const char *cmdline, const char *option)
+{
+ int ret;
+
+ ret = __cmdline_find_option_bool(cmdline, COMMAND_LINE_SIZE, option);
+ if (ret > 0)
+ return ret;
+
+ if (IS_ENABLED(CONFIG_CMDLINE_BOOL) && !builtin_cmdline_added)
+ return __cmdline_find_option_bool(builtin_cmdline, COMMAND_LINE_SIZE, option);
+
+ return ret;
+}
+
+int cmdline_find_option(const char *cmdline, const char *option, char *buffer,
+ int bufsize)
+{
+ int ret;
+
+ ret = __cmdline_find_option(cmdline, COMMAND_LINE_SIZE, option, buffer, bufsize);
+ if (ret > 0)
+ return ret;
+
+ if (IS_ENABLED(CONFIG_CMDLINE_BOOL) && !builtin_cmdline_added)
+ return __cmdline_find_option(builtin_cmdline, COMMAND_LINE_SIZE, option, buffer, bufsize);
+
+ return ret;
+}