Merge Linus master into drm-next

The merge is clean, but the arm build fails afterwards,
due to API changes in the regulator tree.

I've included the patch into the merge to fix the build.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 140 insertions, 23 deletions

diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 703130f469ec..aef653193160 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -52,10 +52,25 @@ 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)
+
+#define DUMP_BYTES(buf, len, fmt, args...)				\
+do {									\
+	if (unlikely(debug_alternative)) {				\
+		int j;							\
+									\
+		if (!(len))						\
+			break;						\
+									\
+		printk(KERN_DEBUG fmt, ##args);				\
+		for (j = 0; j < (len) - 1; j++)				\
+			printk(KERN_CONT "%02hhx ", buf[j]);		\
+		printk(KERN_CONT "%02hhx\n", buf[j]);			\
+	}								\
 } while (0)
 
 /*
@@ -243,12 +258,89 @@ 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. */
+/*
+ * Are we looking at a near JMP with a 1 or 4-byte displacement.
+ */
+static inline bool is_jmp(const u8 opcode)
+{
+	return opcode == 0xeb || opcode == 0xe9;
+}
+
+static void __init_or_module
+recompute_jump(struct alt_instr *a, u8 *orig_insn, u8 *repl_insn, u8 *insnbuf)
+{
+	u8 *next_rip, *tgt_rip;
+	s32 n_dspl, o_dspl;
+	int repl_len;
+
+	if (a->replacementlen != 5)
+		return;
+
+	o_dspl = *(s32 *)(insnbuf + 1);
+
+	/* next_rip of the replacement JMP */
+	next_rip = repl_insn + a->replacementlen;
+	/* target rip of the replacement JMP */
+	tgt_rip  = next_rip + o_dspl;
+	n_dspl = tgt_rip - orig_insn;
+
+	DPRINTK("target RIP: %p, new_displ: 0x%x", tgt_rip, n_dspl);
+
+	if (tgt_rip - orig_insn >= 0) {
+		if (n_dspl - 2 <= 127)
+			goto two_byte_jmp;
+		else
+			goto five_byte_jmp;
+	/* negative offset */
+	} else {
+		if (((n_dspl - 2) & 0xff) == (n_dspl - 2))
+			goto two_byte_jmp;
+		else
+			goto five_byte_jmp;
+	}
+
+two_byte_jmp:
+	n_dspl -= 2;
+
+	insnbuf[0] = 0xeb;
+	insnbuf[1] = (s8)n_dspl;
+	add_nops(insnbuf + 2, 3);
+
+	repl_len = 2;
+	goto done;
+
+five_byte_jmp:
+	n_dspl -= 5;
+
+	insnbuf[0] = 0xe9;
+	*(s32 *)&insnbuf[1] = n_dspl;
 
+	repl_len = 5;
+
+done:
+
+	DPRINTK("final displ: 0x%08x, JMP 0x%lx",
+		n_dspl, (unsigned long)orig_insn + n_dspl + repl_len);
+}
+
+static void __init_or_module optimize_nops(struct alt_instr *a, u8 *instr)
+{
+	if (instr[0] != 0x90)
+		return;
+
+	add_nops(instr + (a->instrlen - a->padlen), a->padlen);
+
+	DUMP_BYTES(instr, a->instrlen, "%p: [%d:%d) optimized NOPs: ",
+		   instr, a->instrlen - a->padlen, a->padlen);
+}
+
+/*
+ * 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 +348,10 @@ 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.
 	 *
@@ -267,29 +359,54 @@ void __init_or_module apply_alternatives(struct alt_instr *start,
 	 * order.
 	 */
 	for (a = start; a < end; a++) {
+		int insnbuf_sz = 0;
+
 		instr = (u8 *)&a->instr_offset + a->instr_offset;
 		replacement = (u8 *)&a->repl_offset + a->repl_offset;
-		BUG_ON(a->replacementlen > a->instrlen);
 		BUG_ON(a->instrlen > sizeof(insnbuf));
 		BUG_ON(a->cpuid >= (NCAPINTS + NBUGINTS) * 32);
-		if (!boot_cpu_has(a->cpuid))
+		if (!boot_cpu_has(a->cpuid)) {
+			if (a->padlen > 1)
+				optimize_nops(a, instr);
+
 			continue;
+		}
+
+		DPRINTK("feat: %d*32+%d, old: (%p, len: %d), repl: (%p, len: %d), pad: %d",
+			a->cpuid >> 5,
+			a->cpuid & 0x1f,
+			instr, a->instrlen,
+			replacement, a->replacementlen, a->padlen);
+
+		DUMP_BYTES(instr, a->instrlen, "%p: old_insn: ", instr);
+		DUMP_BYTES(replacement, a->replacementlen, "%p: rpl_insn: ", replacement);
 
 		memcpy(insnbuf, replacement, a->replacementlen);
+		insnbuf_sz = 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, CALL 0x%lx",
+				*(s32 *)(insnbuf + 1),
+				(unsigned long)instr + *(s32 *)(insnbuf + 1) + 5);
+		}
+
+		if (a->replacementlen && is_jmp(replacement[0]))
+			recompute_jump(a, instr, replacement, insnbuf);
 
-		add_nops(insnbuf + a->replacementlen,
-			 a->instrlen - a->replacementlen);
+		if (a->instrlen > a->replacementlen) {
+			add_nops(insnbuf + a->replacementlen,
+				 a->instrlen - a->replacementlen);
+			insnbuf_sz += a->instrlen - a->replacementlen;
+		}
+		DUMP_BYTES(insnbuf, insnbuf_sz, "%p: final_insn: ", instr);
 
-		text_poke_early(instr, insnbuf, a->instrlen);
+		text_poke_early(instr, insnbuf, insnbuf_sz);
 	}
 }
 
 #ifdef CONFIG_SMP
-
 static void alternatives_smp_lock(const s32 *start, const s32 *end,
 				  u8 *text, u8 *text_end)
 {
@@ -371,8 +488,8 @@ 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);
@@ -440,7 +557,7 @@ int alternatives_text_reserved(void *start, void *end)
 
 	return 0;
 }
-#endif
+#endif /* CONFIG_SMP */
 
 #ifdef CONFIG_PARAVIRT
 void __init_or_module apply_paravirt(struct paravirt_patch_site *start,
@@ -601,7 +718,7 @@ int poke_int3_handler(struct pt_regs *regs)
 	if (likely(!bp_patching_in_progress))
 		return 0;
 
-	if (user_mode_vm(regs) || regs->ip != (unsigned long)bp_int3_addr)
+	if (user_mode(regs) || regs->ip != (unsigned long)bp_int3_addr)
 		return 0;
 
 	/* set up the specified breakpoint handler */