@@ -6,7 +6,11 @@ subdir-y += mm
subdir-$(CONFIG_XENOPROF) += oprofile
subdir-y += x86_64
+ifdef CONFIG_XSPLICE
+obj-y += alternative.o
+else
obj-bin-y += alternative.init.o
+endif
obj-y += apic.o
obj-y += bitops.o
obj-bin-y += bzimage.init.o
@@ -22,13 +22,14 @@
#include <asm/system.h>
#include <asm/traps.h>
#include <asm/nmi.h>
+#include <xen/xsplice.h>
#define MAX_PATCH_LEN (255-1)
extern struct alt_instr __alt_instructions[], __alt_instructions_end[];
#ifdef K8_NOP1
-static const unsigned char k8nops[] __initconst = {
+static const unsigned char k8nops[] __INITCONST = {
K8_NOP1,
K8_NOP2,
K8_NOP3,
@@ -52,7 +53,7 @@ static const unsigned char * const k8_nops[ASM_NOP_MAX+1] __initconstrel = {
#endif
#ifdef P6_NOP1
-static const unsigned char p6nops[] __initconst = {
+static const unsigned char p6nops[] __INITCONST = {
P6_NOP1,
P6_NOP2,
P6_NOP3,
@@ -75,7 +76,7 @@ static const unsigned char * const p6_nops[ASM_NOP_MAX+1] __initconstrel = {
};
#endif
-static const unsigned char * const *ideal_nops __initdata = k8_nops;
+static const unsigned char * const *ideal_nops __INITDATA = k8_nops;
static int __init mask_nmi_callback(const struct cpu_user_regs *regs, int cpu)
{
@@ -100,7 +101,7 @@ static void __init arch_init_ideal_nops(void)
}
/* Use this to add nops to a buffer, then text_poke the whole buffer. */
-static void __init add_nops(void *insns, unsigned int len)
+static void __INIT add_nops(void *insns, unsigned int len)
{
while ( len > 0 )
{
@@ -114,7 +115,7 @@ static void __init add_nops(void *insns, unsigned int len)
}
/*
- * text_poke_early - Update instructions on a live kernel at boot time
+ * text_poke - Update instructions on a live kernel or non-executed code.
* @addr: address to modify
* @opcode: source of the copy
* @len: length to copy
@@ -125,9 +126,10 @@ static void __init add_nops(void *insns, unsigned int len)
* instructions. And on the local CPU you need to be protected again NMI or MCE
* handlers seeing an inconsistent instruction while you patch.
*
- * This routine is called with local interrupt disabled.
+ * You should run this with interrupts disabled or on code that has never
+ * been executed.
*/
-static void *__init text_poke_early(void *addr, const void *opcode, size_t len)
+static void *__INIT text_poke(void *addr, const void *opcode, size_t len)
{
memcpy(addr, opcode, len);
sync_core();
@@ -142,20 +144,14 @@ static void *__init text_poke_early(void *addr, const void *opcode, size_t len)
* APs have less capabilities than the boot processor are not handled.
* Tough. Make sure you disable such features by hand.
*/
-static void __init apply_alternatives(struct alt_instr *start, struct alt_instr *end)
+void __INIT apply_alternatives_nocheck(struct alt_instr *start, struct alt_instr *end)
{
struct alt_instr *a;
u8 *instr, *replacement;
u8 insnbuf[MAX_PATCH_LEN];
- unsigned long cr0 = read_cr0();
-
- ASSERT(!local_irq_is_enabled());
printk(KERN_INFO "alt table %p -> %p\n", start, end);
- /* Disable WP to allow application of alternatives to read-only pages. */
- write_cr0(cr0 & ~X86_CR0_WP);
-
/*
* The scan order should be from start to end. A later scanned
* alternative code can overwrite a previous scanned alternative code.
@@ -183,8 +179,24 @@ static void __init apply_alternatives(struct alt_instr *start, struct alt_instr
add_nops(insnbuf + a->replacementlen,
a->instrlen - a->replacementlen);
- text_poke_early(instr, insnbuf, a->instrlen);
+ text_poke(instr, insnbuf, a->instrlen);
}
+}
+
+/*
+ * This routine is called with local interrupt disabled and used during
+ * bootup.
+ */
+void __init apply_alternatives(struct alt_instr *start, struct alt_instr *end)
+{
+ unsigned long cr0 = read_cr0();
+
+ ASSERT(!local_irq_is_enabled());
+
+ /* Disable WP to allow application of alternatives to read-only pages. */
+ write_cr0(cr0 & ~X86_CR0_WP);
+
+ apply_alternatives_nocheck(start, end);
/* Reinstate WP. */
write_cr0(cr0);
@@ -3,6 +3,9 @@
*
*/
+#include <asm/alternative.h>
+#include <asm/nops.h>
+#include <asm/uaccess.h>
#include <xen/types.h>
static unsigned long *non_canonical_addr = (unsigned long *)(0xdead000000000000ULL);
@@ -12,6 +15,8 @@ const char *xen_hello_world(void)
{
unsigned long tmp;
int rc;
+
+ alternative(ASM_NOP1, ASM_NOP1, X86_FEATURE_LM);
/*
* Any BUG, or WARN_ON will contain symbol and payload name. Furthermore
* exceptions will be caught and processed properly.
@@ -530,6 +530,39 @@ static int prepare_payload(struct payload *payload,
}
#ifndef CONFIG_ARM
+ sec = xsplice_elf_sec_by_name(elf, ".altinstructions");
+ if ( sec )
+ {
+ struct alt_instr *a, *start, *end;
+
+ if ( !sec->sec->sh_size ||
+ (sec->sec->sh_size % sizeof(*a)) )
+ {
+ dprintk(XENLOG_DEBUG, XSPLICE "%s: Wrong size of .alt_instr (exp:%lu vs %lu)!\n",
+ elf->name, sizeof(*a),
+ sec->sec->sh_size);
+ return -EINVAL;
+ }
+
+ start = sec->load_addr;
+ end = sec->load_addr + sec->sec->sh_size;
+
+ for ( a = start; a < end; a++ )
+ {
+ unsigned long instr = (unsigned long)(&a->instr_offset + a->instr_offset);
+ unsigned long replacement = (unsigned long)(&a->repl_offset + a->repl_offset);
+
+ if ( (instr < region->start && instr >= region->end) ||
+ (replacement < region->start && replacement >= region->end) )
+ {
+ dprintk(XENLOG_DEBUG, XSPLICE "%s Alt patching outside payload: 0x%lx!\n",
+ elf->name, instr);
+ return -EINVAL;
+ }
+ }
+ apply_alternatives_nocheck(start, end);
+ }
+
sec = xsplice_elf_sec_by_name(elf, ".ex_table");
if ( sec )
{
@@ -552,6 +585,7 @@ static int prepare_payload(struct payload *payload,
region->ex = s;
region->ex_end = e;
}
+
#endif
return 0;
@@ -23,6 +23,10 @@ struct alt_instr {
u8 replacementlen; /* length of new instruction, <= instrlen */
};
+/* Similar to apply_alternatives except it can be run with IRQs enabled. */
+extern void apply_alternatives_nocheck(struct alt_instr *start,
+ struct alt_instr *end);
+extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
extern void alternative_instructions(void);
#define OLDINSTR(oldinstr) "661:\n\t" oldinstr "\n662:\n"