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authorGreg Kroah-Hartman <gregkh@google.com>2018-01-06 10:53:18 +0100
committerGreg Kroah-Hartman <gregkh@google.com>2018-01-06 10:53:18 +0100
commit5cc8c2ec619e3ce3439b3ae19b22d487e0e3a86b (patch)
treeacbbbad06cbee2341a66978675b9c9982c9f5636 /arch/x86/lib/cmdline.c
parenta51b84097d2103264f8b0759942e313317bccd78 (diff)
parentb3e3db15b45027e3b77ec7f722e2b7210b1bf726 (diff)
Merge 4.4.110 into android-4.4
Changes in 4.4.110 x86/boot: Add early cmdline parsing for options with arguments KAISER: Kernel Address Isolation kaiser: merged update kaiser: do not set _PAGE_NX on pgd_none kaiser: stack map PAGE_SIZE at THREAD_SIZE-PAGE_SIZE kaiser: fix build and FIXME in alloc_ldt_struct() kaiser: KAISER depends on SMP kaiser: fix regs to do_nmi() ifndef CONFIG_KAISER kaiser: fix perf crashes kaiser: ENOMEM if kaiser_pagetable_walk() NULL kaiser: tidied up asm/kaiser.h somewhat kaiser: tidied up kaiser_add/remove_mapping slightly kaiser: kaiser_remove_mapping() move along the pgd kaiser: cleanups while trying for gold link kaiser: name that 0x1000 KAISER_SHADOW_PGD_OFFSET kaiser: delete KAISER_REAL_SWITCH option kaiser: vmstat show NR_KAISERTABLE as nr_overhead kaiser: enhanced by kernel and user PCIDs kaiser: load_new_mm_cr3() let SWITCH_USER_CR3 flush user kaiser: PCID 0 for kernel and 128 for user kaiser: x86_cr3_pcid_noflush and x86_cr3_pcid_user kaiser: paranoid_entry pass cr3 need to paranoid_exit kaiser: _pgd_alloc() without __GFP_REPEAT to avoid stalls kaiser: fix unlikely error in alloc_ldt_struct() kaiser: add "nokaiser" boot option, using ALTERNATIVE x86/kaiser: Rename and simplify X86_FEATURE_KAISER handling x86/kaiser: Check boottime cmdline params kaiser: use ALTERNATIVE instead of x86_cr3_pcid_noflush kaiser: drop is_atomic arg to kaiser_pagetable_walk() kaiser: asm/tlbflush.h handle noPGE at lower level kaiser: kaiser_flush_tlb_on_return_to_user() check PCID x86/paravirt: Dont patch flush_tlb_single x86/kaiser: Reenable PARAVIRT kaiser: disabled on Xen PV x86/kaiser: Move feature detection up KPTI: Rename to PAGE_TABLE_ISOLATION KPTI: Report when enabled x86, vdso, pvclock: Simplify and speed up the vdso pvclock reader x86/vdso: Get pvclock data from the vvar VMA instead of the fixmap x86/kasan: Clear kasan_zero_page after TLB flush kaiser: Set _PAGE_NX only if supported Linux 4.4.110 Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Diffstat (limited to 'arch/x86/lib/cmdline.c')
-rw-r--r--arch/x86/lib/cmdline.c105
1 files changed, 105 insertions, 0 deletions
diff --git a/arch/x86/lib/cmdline.c b/arch/x86/lib/cmdline.c
index 422db000d727..a744506856b1 100644
--- a/arch/x86/lib/cmdline.c
+++ b/arch/x86/lib/cmdline.c
@@ -82,3 +82,108 @@ int cmdline_find_option_bool(const char *cmdline, const char *option)
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;
+ /* fall through */
+
+ 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;
+ /* fall through */
+
+ 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(const char *cmdline, const char *option, char *buffer,
+ int bufsize)
+{
+ return __cmdline_find_option(cmdline, COMMAND_LINE_SIZE, option,
+ buffer, bufsize);
+}