x86/alternatives: Cleanup DPRINTK macro

Make it pass __func__ implicitly. Also, dump info about each replacing
we're doing. Fixup comments and style while at it.

Signed-off-by: Borislav Petkov <bp@suse.de>

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 703130f469ecf71978b9d67bf0fb50da9b31cbc9..1e86e85bcf5874bd02969925c1aed8f5b226b42b 100644 (file)
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -52,10 +52,10 @@ static int __init setup_noreplace_paravirt(char *str)
 __setup("noreplace-paravirt", setup_noreplace_paravirt);
 #endif
 
-#define DPRINTK(fmt, ...)                              \
-do {                                                   \
-       if (debug_alternative)                          \
-               printk(KERN_DEBUG fmt, ##__VA_ARGS__);  \
+#define DPRINTK(fmt, args...)                                          \
+do {                                                                   \
+       if (debug_alternative)                                          \
+               printk(KERN_DEBUG "%s: " fmt "\n", __func__, ##args);   \
 } while (0)
 
 /*
@@ -243,12 +243,13 @@ extern struct alt_instr __alt_instructions[], __alt_instructions_end[];
 extern s32 __smp_locks[], __smp_locks_end[];
 void *text_poke_early(void *addr, const void *opcode, size_t len);
 
-/* Replace instructions with better alternatives for this CPU type.
-   This runs before SMP is initialized to avoid SMP problems with
-   self modifying code. This implies that asymmetric systems where
-   APs have less capabilities than the boot processor are not handled.
-   Tough. Make sure you disable such features by hand. */
-
+/*
+ * Replace instructions with better alternatives for this CPU type. This runs
+ * before SMP is initialized to avoid SMP problems with self modifying code.
+ * This implies that asymmetric systems where APs have less capabilities than
+ * the boot processor are not handled. Tough. Make sure you disable such
+ * features by hand.
+ */
 void __init_or_module apply_alternatives(struct alt_instr *start,
                                         struct alt_instr *end)
 {
@@ -256,10 +257,10 @@ void __init_or_module apply_alternatives(struct alt_instr *start,
        u8 *instr, *replacement;
        u8 insnbuf[MAX_PATCH_LEN];
 
-       DPRINTK("%s: alt table %p -> %p\n", __func__, start, end);
+       DPRINTK("alt table %p -> %p", start, end);
        /*
         * The scan order should be from start to end. A later scanned
-        * alternative code can overwrite a previous scanned alternative code.
+        * alternative code can overwrite previously scanned alternative code.
         * Some kernel functions (e.g. memcpy, memset, etc) use this order to
         * patch code.
         *
@@ -275,11 +276,19 @@ void __init_or_module apply_alternatives(struct alt_instr *start,
                if (!boot_cpu_has(a->cpuid))
                        continue;
 
+               DPRINTK("feat: %d*32+%d, old: (%p, len: %d), repl: (%p, len: %d)",
+                       a->cpuid >> 5,
+                       a->cpuid & 0x1f,
+                       instr, a->instrlen,
+                       replacement, a->replacementlen);
+
                memcpy(insnbuf, replacement, a->replacementlen);
 
                /* 0xe8 is a relative jump; fix the offset. */
-               if (*insnbuf == 0xe8 && a->replacementlen == 5)
-                   *(s32 *)(insnbuf + 1) += replacement - instr;
+               if (*insnbuf == 0xe8 && a->replacementlen == 5) {
+                       *(s32 *)(insnbuf + 1) += replacement - instr;
+                       DPRINTK("Fix CALL offset: 0x%x", *(s32 *)(insnbuf + 1));
+               }
 
                add_nops(insnbuf + a->replacementlen,
                         a->instrlen - a->replacementlen);
@@ -371,8 +380,8 @@ void __init_or_module alternatives_smp_module_add(struct module *mod,
        smp->locks_end  = locks_end;
        smp->text       = text;
        smp->text_end   = text_end;
-       DPRINTK("%s: locks %p -> %p, text %p -> %p, name %s\n",
-               __func__, smp->locks, smp->locks_end,
+       DPRINTK("locks %p -> %p, text %p -> %p, name %s\n",
+               smp->locks, smp->locks_end,
                smp->text, smp->text_end, smp->name);
 
        list_add_tail(&smp->next, &smp_alt_modules);