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Commit db477a33 authored by Borislav Petkov's avatar Borislav Petkov
Browse files

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: default avatarBorislav Petkov <bp@suse.de>
parent 338ea555

arch/x86/kernel/alternative.c

+25 −16
Original line number Diff line number Diff line
@@ -52,10 +52,10 @@ static int __init setup_noreplace_paravirt(char *str) 
__setup("noreplace-paravirt", setup_noreplace_paravirt);

#endif



#define DPRINTK(fmt, ...)				\

#define DPRINTK(fmt, args...)						\

do {									\

	if (debug_alternative)						\

		printk(KERN_DEBUG fmt, ##__VA_ARGS__);	\

		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)

		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);