summaryrefslogtreecommitdiffstats
path: root/arch/x86/lib/strstr_32.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/x86/lib/strstr_32.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 4.19.249.upstream/4.19.249upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/lib/strstr_32.c')
-rw-r--r--arch/x86/lib/strstr_32.c33
1 files changed, 33 insertions, 0 deletions
diff --git a/arch/x86/lib/strstr_32.c b/arch/x86/lib/strstr_32.c
new file mode 100644
index 000000000..38f37df05
--- /dev/null
+++ b/arch/x86/lib/strstr_32.c
@@ -0,0 +1,33 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/string.h>
+#include <linux/export.h>
+
+char *strstr(const char *cs, const char *ct)
+{
+int d0, d1;
+register char *__res;
+__asm__ __volatile__(
+ "movl %6,%%edi\n\t"
+ "repne\n\t"
+ "scasb\n\t"
+ "notl %%ecx\n\t"
+ "decl %%ecx\n\t" /* NOTE! This also sets Z if searchstring='' */
+ "movl %%ecx,%%edx\n"
+ "1:\tmovl %6,%%edi\n\t"
+ "movl %%esi,%%eax\n\t"
+ "movl %%edx,%%ecx\n\t"
+ "repe\n\t"
+ "cmpsb\n\t"
+ "je 2f\n\t" /* also works for empty string, see above */
+ "xchgl %%eax,%%esi\n\t"
+ "incl %%esi\n\t"
+ "cmpb $0,-1(%%eax)\n\t"
+ "jne 1b\n\t"
+ "xorl %%eax,%%eax\n\t"
+ "2:"
+ : "=a" (__res), "=&c" (d0), "=&S" (d1)
+ : "0" (0), "1" (0xffffffff), "2" (cs), "g" (ct)
+ : "dx", "di");
+return __res;
+}
+EXPORT_SYMBOL(strstr);