Clone the implementations of strrchr() and memchr() in lib/string.c so
we can use them in the standalone zboot decompressor app. These routines
are used by the FDT handling code.
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
arch/arm64/kernel/image-vars.h | 3 -
arch/riscv/kernel/image-vars.h | 2 -
drivers/firmware/efi/libstub/Makefile | 2 +
drivers/firmware/efi/libstub/string.c | 62 ++++++++++++++++++++
4 files changed, 64 insertions(+), 5 deletions(-)
diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index ace584e0b065..f31130ba0233 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -21,9 +21,6 @@ PROVIDE(__efistub_primary_entry_offset = primary_entry - _text);
* linked at. The routines below are all implemented in assembler in a
* position independent manner
*/
-PROVIDE(__efistub_memchr = __pi_memchr);
-PROVIDE(__efistub_strcmp = __pi_strcmp);
-PROVIDE(__efistub_strrchr = __pi_strrchr);
PROVIDE(__efistub_dcache_clean_poc = __pi_dcache_clean_poc);
PROVIDE(__efistub__text = _text);
diff --git a/arch/riscv/kernel/image-vars.h b/arch/riscv/kernel/image-vars.h
index 4913abd6dd10..7e2962ef73f9 100644
--- a/arch/riscv/kernel/image-vars.h
+++ b/arch/riscv/kernel/image-vars.h
@@ -23,9 +23,7 @@
* linked at. The routines below are all implemented in assembler in a
* position independent manner
*/
-__efistub_memchr = memchr;
__efistub_strcmp = strcmp;
-__efistub_strrchr = strrchr;
__efistub__start = _start;
__efistub__start_kernel = _start_kernel;
diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index 53304e9c6778..6824ee5a4ae6 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -21,6 +21,8 @@ cflags-$(CONFIG_X86) += -m$(BITS) -D__KERNEL__ \
cflags-$(CONFIG_ARM64) := -fpie $(DISABLE_STACKLEAK_PLUGIN) \
$(call cc-option,-mbranch-protection=none)
cflags-$(CONFIG_ARM) := -DEFI_HAVE_STRLEN -DEFI_HAVE_STRNLEN \
+ -DEFI_HAVE_MEMCHR -DEFI_HAVE_STRRCHR \
+ -DEFI_HAVE_STRCMP \
-fno-builtin -fpic \
$(call cc-option,-mno-single-pic-base)
cflags-$(CONFIG_RISCV) := -fpic
diff --git a/drivers/firmware/efi/libstub/string.c b/drivers/firmware/efi/libstub/string.c
index 5a1519d435bf..168fe8e79abc 100644
--- a/drivers/firmware/efi/libstub/string.c
+++ b/drivers/firmware/efi/libstub/string.c
@@ -64,6 +64,28 @@ char *strstr(const char *s1, const char *s2)
return NULL;
}
+#ifndef EFI_HAVE_STRCMP
+/**
+ * strcmp - Compare two strings
+ * @cs: One string
+ * @ct: Another string
+ */
+int strcmp(const char *cs, const char *ct)
+{
+ unsigned char c1, c2;
+
+ while (1) {
+ c1 = *cs++;
+ c2 = *ct++;
+ if (c1 != c2)
+ return c1 < c2 ? -1 : 1;
+ if (!c1)
+ break;
+ }
+ return 0;
+}
+#endif
+
/**
* strncmp - Compare two length-limited strings
* @cs: One string
@@ -140,3 +162,43 @@ long simple_strtol(const char *cp, char **endp, unsigned int base)
return simple_strtoull(cp, endp, base);
}
+
+#ifdef CONFIG_EFI_PARAMS_FROM_FDT
+#ifndef EFI_HAVE_STRRCHR
+/**
+ * strrchr - Find the last occurrence of a character in a string
+ * @s: The string to be searched
+ * @c: The character to search for
+ */
+char *strrchr(const char *s, int c)
+{
+ const char *last = NULL;
+ do {
+ if (*s == (char)c)
+ last = s;
+ } while (*s++);
+ return (char *)last;
+}
+#endif
+#ifndef EFI_HAVE_MEMCHR
+/**
+ * memchr - Find a character in an area of memory.
+ * @s: The memory area
+ * @c: The byte to search for
+ * @n: The size of the area.
+ *
+ * returns the address of the first occurrence of @c, or %NULL
+ * if @c is not found
+ */
+void *memchr(const void *s, int c, size_t n)
+{
+ const unsigned char *p = s;
+ while (n-- != 0) {
+ if ((unsigned char)c == *p++) {
+ return (void *)(p - 1);
+ }
+ }
+ return NULL;
+}
+#endif
+#endif
--
2.35.1
