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-rw-r--r--arch/powerpc/include/asm/code-patching.h41
1 files changed, 41 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h
index 8ab937771068..abef812de7f8 100644
--- a/arch/powerpc/include/asm/code-patching.h
+++ b/arch/powerpc/include/asm/code-patching.h
@@ -12,6 +12,8 @@
#include <asm/types.h>
#include <asm/ppc-opcode.h>
+#include <linux/string.h>
+#include <linux/kallsyms.h>
/* Flags for create_branch:
* "b" == create_branch(addr, target, 0);
@@ -99,6 +101,45 @@ static inline unsigned long ppc_global_function_entry(void *func)
#endif
}
+/*
+ * Wrapper around kallsyms_lookup() to return function entry address:
+ * - For ABIv1, we lookup the dot variant.
+ * - For ABIv2, we return the local entry point.
+ */
+static inline unsigned long ppc_kallsyms_lookup_name(const char *name)
+{
+ unsigned long addr;
+#ifdef PPC64_ELF_ABI_v1
+ /* check for dot variant */
+ char dot_name[1 + KSYM_NAME_LEN];
+ bool dot_appended = false;
+
+ if (strnlen(name, KSYM_NAME_LEN) >= KSYM_NAME_LEN)
+ return 0;
+
+ if (name[0] != '.') {
+ dot_name[0] = '.';
+ dot_name[1] = '\0';
+ strlcat(dot_name, name, sizeof(dot_name));
+ dot_appended = true;
+ } else {
+ dot_name[0] = '\0';
+ strlcat(dot_name, name, sizeof(dot_name));
+ }
+ addr = kallsyms_lookup_name(dot_name);
+ if (!addr && dot_appended)
+ /* Let's try the original non-dot symbol lookup */
+ addr = kallsyms_lookup_name(name);
+#elif defined(PPC64_ELF_ABI_v2)
+ addr = kallsyms_lookup_name(name);
+ if (addr)
+ addr = ppc_function_entry((void *)addr);
+#else
+ addr = kallsyms_lookup_name(name);
+#endif
+ return addr;
+}
+
#ifdef CONFIG_PPC64
/*
* Some instruction encodings commonly used in dynamic ftracing