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-rw-r--r--arch/powerpc/lib/code-patching.c497
1 files changed, 49 insertions, 448 deletions
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index c5ed98823835..906d43463366 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -3,22 +3,18 @@
* Copyright 2008 Michael Ellerman, IBM Corporation.
*/
-#include <linux/kernel.h>
#include <linux/kprobes.h>
#include <linux/vmalloc.h>
#include <linux/init.h>
-#include <linux/mm.h>
#include <linux/cpuhotplug.h>
-#include <linux/slab.h>
#include <linux/uaccess.h>
#include <asm/tlbflush.h>
#include <asm/page.h>
#include <asm/code-patching.h>
-#include <asm/setup.h>
#include <asm/inst.h>
-static int __patch_instruction(u32 *exec_addr, struct ppc_inst instr, u32 *patch_addr)
+static int __patch_instruction(u32 *exec_addr, ppc_inst_t instr, u32 *patch_addr)
{
if (!ppc_inst_prefixed(instr)) {
u32 val = ppc_inst_val(instr);
@@ -39,7 +35,7 @@ failed:
return -EFAULT;
}
-int raw_patch_instruction(u32 *addr, struct ppc_inst instr)
+int raw_patch_instruction(u32 *addr, ppc_inst_t instr)
{
return __patch_instruction(addr, instr, addr);
}
@@ -86,23 +82,16 @@ void __init poking_init(void)
static int map_patch_area(void *addr, unsigned long text_poke_addr)
{
unsigned long pfn;
- int err;
if (is_vmalloc_or_module_addr(addr))
pfn = vmalloc_to_pfn(addr);
else
pfn = __pa_symbol(addr) >> PAGE_SHIFT;
- err = map_kernel_page(text_poke_addr, (pfn << PAGE_SHIFT), PAGE_KERNEL);
-
- pr_devel("Mapped addr %lx with pfn %lx:%d\n", text_poke_addr, pfn, err);
- if (err)
- return -1;
-
- return 0;
+ return map_kernel_page(text_poke_addr, (pfn << PAGE_SHIFT), PAGE_KERNEL);
}
-static inline int unmap_patch_area(unsigned long addr)
+static void unmap_patch_area(unsigned long addr)
{
pte_t *ptep;
pmd_t *pmdp;
@@ -111,43 +100,56 @@ static inline int unmap_patch_area(unsigned long addr)
pgd_t *pgdp;
pgdp = pgd_offset_k(addr);
- if (unlikely(!pgdp))
- return -EINVAL;
+ if (WARN_ON(pgd_none(*pgdp)))
+ return;
p4dp = p4d_offset(pgdp, addr);
- if (unlikely(!p4dp))
- return -EINVAL;
+ if (WARN_ON(p4d_none(*p4dp)))
+ return;
pudp = pud_offset(p4dp, addr);
- if (unlikely(!pudp))
- return -EINVAL;
+ if (WARN_ON(pud_none(*pudp)))
+ return;
pmdp = pmd_offset(pudp, addr);
- if (unlikely(!pmdp))
- return -EINVAL;
+ if (WARN_ON(pmd_none(*pmdp)))
+ return;
ptep = pte_offset_kernel(pmdp, addr);
- if (unlikely(!ptep))
- return -EINVAL;
-
- pr_devel("clearing mm %p, pte %p, addr %lx\n", &init_mm, ptep, addr);
+ if (WARN_ON(pte_none(*ptep)))
+ return;
/*
* In hash, pte_clear flushes the tlb, in radix, we have to
*/
pte_clear(&init_mm, addr, ptep);
flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
+}
- return 0;
+static int __do_patch_instruction(u32 *addr, ppc_inst_t instr)
+{
+ int err;
+ u32 *patch_addr;
+ unsigned long text_poke_addr;
+
+ text_poke_addr = (unsigned long)__this_cpu_read(text_poke_area)->addr;
+ patch_addr = (u32 *)(text_poke_addr + offset_in_page(addr));
+
+ err = map_patch_area(addr, text_poke_addr);
+ if (err)
+ return err;
+
+ err = __patch_instruction(addr, instr, patch_addr);
+
+ unmap_patch_area(text_poke_addr);
+
+ return err;
}
-static int do_patch_instruction(u32 *addr, struct ppc_inst instr)
+static int do_patch_instruction(u32 *addr, ppc_inst_t instr)
{
int err;
- u32 *patch_addr = NULL;
unsigned long flags;
- unsigned long text_poke_addr;
- unsigned long kaddr = (unsigned long)addr;
/*
* During early early boot patch_instruction is called
@@ -158,51 +160,37 @@ static int do_patch_instruction(u32 *addr, struct ppc_inst instr)
return raw_patch_instruction(addr, instr);
local_irq_save(flags);
-
- text_poke_addr = (unsigned long)__this_cpu_read(text_poke_area)->addr;
- if (map_patch_area(addr, text_poke_addr)) {
- err = -1;
- goto out;
- }
-
- patch_addr = (u32 *)(text_poke_addr + (kaddr & ~PAGE_MASK));
-
- __patch_instruction(addr, instr, patch_addr);
-
- err = unmap_patch_area(text_poke_addr);
- if (err)
- pr_warn("failed to unmap %lx\n", text_poke_addr);
-
-out:
+ err = __do_patch_instruction(addr, instr);
local_irq_restore(flags);
return err;
}
#else /* !CONFIG_STRICT_KERNEL_RWX */
-static int do_patch_instruction(u32 *addr, struct ppc_inst instr)
+static int do_patch_instruction(u32 *addr, ppc_inst_t instr)
{
return raw_patch_instruction(addr, instr);
}
#endif /* CONFIG_STRICT_KERNEL_RWX */
-int patch_instruction(u32 *addr, struct ppc_inst instr)
+int patch_instruction(u32 *addr, ppc_inst_t instr)
{
/* Make sure we aren't patching a freed init section */
- if (init_mem_is_free && init_section_contains(addr, 4)) {
- pr_debug("Skipping init section patching addr: 0x%px\n", addr);
+ if (system_state >= SYSTEM_FREEING_INITMEM && init_section_contains(addr, 4))
return 0;
- }
+
return do_patch_instruction(addr, instr);
}
NOKPROBE_SYMBOL(patch_instruction);
int patch_branch(u32 *addr, unsigned long target, int flags)
{
- struct ppc_inst instr;
+ ppc_inst_t instr;
+
+ if (create_branch(&instr, addr, target, flags))
+ return -ERANGE;
- create_branch(&instr, addr, target, flags);
return patch_instruction(addr, instr);
}
@@ -237,7 +225,7 @@ bool is_offset_in_cond_branch_range(long offset)
* Helper to check if a given instruction is a conditional branch
* Derived from the conditional checks in analyse_instr()
*/
-bool is_conditional_branch(struct ppc_inst instr)
+bool is_conditional_branch(ppc_inst_t instr)
{
unsigned int opcode = ppc_inst_primary_opcode(instr);
@@ -255,7 +243,7 @@ bool is_conditional_branch(struct ppc_inst instr)
}
NOKPROBE_SYMBOL(is_conditional_branch);
-int create_branch(struct ppc_inst *instr, const u32 *addr,
+int create_branch(ppc_inst_t *instr, const u32 *addr,
unsigned long target, int flags)
{
long offset;
@@ -275,7 +263,7 @@ int create_branch(struct ppc_inst *instr, const u32 *addr,
return 0;
}
-int create_cond_branch(struct ppc_inst *instr, const u32 *addr,
+int create_cond_branch(ppc_inst_t *instr, const u32 *addr,
unsigned long target, int flags)
{
long offset;
@@ -294,22 +282,7 @@ int create_cond_branch(struct ppc_inst *instr, const u32 *addr,
return 0;
}
-static unsigned int branch_opcode(struct ppc_inst instr)
-{
- return ppc_inst_primary_opcode(instr) & 0x3F;
-}
-
-static int instr_is_branch_iform(struct ppc_inst instr)
-{
- return branch_opcode(instr) == 18;
-}
-
-static int instr_is_branch_bform(struct ppc_inst instr)
-{
- return branch_opcode(instr) == 16;
-}
-
-int instr_is_relative_branch(struct ppc_inst instr)
+int instr_is_relative_branch(ppc_inst_t instr)
{
if (ppc_inst_val(instr) & BRANCH_ABSOLUTE)
return 0;
@@ -317,7 +290,7 @@ int instr_is_relative_branch(struct ppc_inst instr)
return instr_is_branch_iform(instr) || instr_is_branch_bform(instr);
}
-int instr_is_relative_link_branch(struct ppc_inst instr)
+int instr_is_relative_link_branch(ppc_inst_t instr)
{
return instr_is_relative_branch(instr) && (ppc_inst_val(instr) & BRANCH_SET_LINK);
}
@@ -364,7 +337,7 @@ unsigned long branch_target(const u32 *instr)
return 0;
}
-int translate_branch(struct ppc_inst *instr, const u32 *dest, const u32 *src)
+int translate_branch(ppc_inst_t *instr, const u32 *dest, const u32 *src)
{
unsigned long target;
target = branch_target(src);
@@ -378,375 +351,3 @@ int translate_branch(struct ppc_inst *instr, const u32 *dest, const u32 *src)
return 1;
}
-
-#ifdef CONFIG_PPC_BOOK3E_64
-void __patch_exception(int exc, unsigned long addr)
-{
- extern unsigned int interrupt_base_book3e;
- unsigned int *ibase = &interrupt_base_book3e;
-
- /* Our exceptions vectors start with a NOP and -then- a branch
- * to deal with single stepping from userspace which stops on
- * the second instruction. Thus we need to patch the second
- * instruction of the exception, not the first one
- */
-
- patch_branch(ibase + (exc / 4) + 1, addr, 0);
-}
-#endif
-
-#ifdef CONFIG_CODE_PATCHING_SELFTEST
-
-static int instr_is_branch_to_addr(const u32 *instr, unsigned long addr)
-{
- if (instr_is_branch_iform(ppc_inst_read(instr)) ||
- instr_is_branch_bform(ppc_inst_read(instr)))
- return branch_target(instr) == addr;
-
- return 0;
-}
-
-static void __init test_trampoline(void)
-{
- asm ("nop;\n");
-}
-
-#define check(x) \
- if (!(x)) printk("code-patching: test failed at line %d\n", __LINE__);
-
-static void __init test_branch_iform(void)
-{
- int err;
- struct ppc_inst instr;
- u32 tmp[2];
- u32 *iptr = tmp;
- unsigned long addr = (unsigned long)tmp;
-
- /* The simplest case, branch to self, no flags */
- check(instr_is_branch_iform(ppc_inst(0x48000000)));
- /* All bits of target set, and flags */
- check(instr_is_branch_iform(ppc_inst(0x4bffffff)));
- /* High bit of opcode set, which is wrong */
- check(!instr_is_branch_iform(ppc_inst(0xcbffffff)));
- /* Middle bits of opcode set, which is wrong */
- check(!instr_is_branch_iform(ppc_inst(0x7bffffff)));
-
- /* Simplest case, branch to self with link */
- check(instr_is_branch_iform(ppc_inst(0x48000001)));
- /* All bits of targets set */
- check(instr_is_branch_iform(ppc_inst(0x4bfffffd)));
- /* Some bits of targets set */
- check(instr_is_branch_iform(ppc_inst(0x4bff00fd)));
- /* Must be a valid branch to start with */
- check(!instr_is_branch_iform(ppc_inst(0x7bfffffd)));
-
- /* Absolute branch to 0x100 */
- patch_instruction(iptr, ppc_inst(0x48000103));
- check(instr_is_branch_to_addr(iptr, 0x100));
- /* Absolute branch to 0x420fc */
- patch_instruction(iptr, ppc_inst(0x480420ff));
- check(instr_is_branch_to_addr(iptr, 0x420fc));
- /* Maximum positive relative branch, + 20MB - 4B */
- patch_instruction(iptr, ppc_inst(0x49fffffc));
- check(instr_is_branch_to_addr(iptr, addr + 0x1FFFFFC));
- /* Smallest negative relative branch, - 4B */
- patch_instruction(iptr, ppc_inst(0x4bfffffc));
- check(instr_is_branch_to_addr(iptr, addr - 4));
- /* Largest negative relative branch, - 32 MB */
- patch_instruction(iptr, ppc_inst(0x4a000000));
- check(instr_is_branch_to_addr(iptr, addr - 0x2000000));
-
- /* Branch to self, with link */
- err = create_branch(&instr, iptr, addr, BRANCH_SET_LINK);
- patch_instruction(iptr, instr);
- check(instr_is_branch_to_addr(iptr, addr));
-
- /* Branch to self - 0x100, with link */
- err = create_branch(&instr, iptr, addr - 0x100, BRANCH_SET_LINK);
- patch_instruction(iptr, instr);
- check(instr_is_branch_to_addr(iptr, addr - 0x100));
-
- /* Branch to self + 0x100, no link */
- err = create_branch(&instr, iptr, addr + 0x100, 0);
- patch_instruction(iptr, instr);
- check(instr_is_branch_to_addr(iptr, addr + 0x100));
-
- /* Maximum relative negative offset, - 32 MB */
- err = create_branch(&instr, iptr, addr - 0x2000000, BRANCH_SET_LINK);
- patch_instruction(iptr, instr);
- check(instr_is_branch_to_addr(iptr, addr - 0x2000000));
-
- /* Out of range relative negative offset, - 32 MB + 4*/
- err = create_branch(&instr, iptr, addr - 0x2000004, BRANCH_SET_LINK);
- check(err);
-
- /* Out of range relative positive offset, + 32 MB */
- err = create_branch(&instr, iptr, addr + 0x2000000, BRANCH_SET_LINK);
- check(err);
-
- /* Unaligned target */
- err = create_branch(&instr, iptr, addr + 3, BRANCH_SET_LINK);
- check(err);
-
- /* Check flags are masked correctly */
- err = create_branch(&instr, iptr, addr, 0xFFFFFFFC);
- patch_instruction(iptr, instr);
- check(instr_is_branch_to_addr(iptr, addr));
- check(ppc_inst_equal(instr, ppc_inst(0x48000000)));
-}
-
-static void __init test_create_function_call(void)
-{
- u32 *iptr;
- unsigned long dest;
- struct ppc_inst instr;
-
- /* Check we can create a function call */
- iptr = (u32 *)ppc_function_entry(test_trampoline);
- dest = ppc_function_entry(test_create_function_call);
- create_branch(&instr, iptr, dest, BRANCH_SET_LINK);
- patch_instruction(iptr, instr);
- check(instr_is_branch_to_addr(iptr, dest));
-}
-
-static void __init test_branch_bform(void)
-{
- int err;
- unsigned long addr;
- struct ppc_inst instr;
- u32 tmp[2];
- u32 *iptr = tmp;
- unsigned int flags;
-
- addr = (unsigned long)iptr;
-
- /* The simplest case, branch to self, no flags */
- check(instr_is_branch_bform(ppc_inst(0x40000000)));
- /* All bits of target set, and flags */
- check(instr_is_branch_bform(ppc_inst(0x43ffffff)));
- /* High bit of opcode set, which is wrong */
- check(!instr_is_branch_bform(ppc_inst(0xc3ffffff)));
- /* Middle bits of opcode set, which is wrong */
- check(!instr_is_branch_bform(ppc_inst(0x7bffffff)));
-
- /* Absolute conditional branch to 0x100 */
- patch_instruction(iptr, ppc_inst(0x43ff0103));
- check(instr_is_branch_to_addr(iptr, 0x100));
- /* Absolute conditional branch to 0x20fc */
- patch_instruction(iptr, ppc_inst(0x43ff20ff));
- check(instr_is_branch_to_addr(iptr, 0x20fc));
- /* Maximum positive relative conditional branch, + 32 KB - 4B */
- patch_instruction(iptr, ppc_inst(0x43ff7ffc));
- check(instr_is_branch_to_addr(iptr, addr + 0x7FFC));
- /* Smallest negative relative conditional branch, - 4B */
- patch_instruction(iptr, ppc_inst(0x43fffffc));
- check(instr_is_branch_to_addr(iptr, addr - 4));
- /* Largest negative relative conditional branch, - 32 KB */
- patch_instruction(iptr, ppc_inst(0x43ff8000));
- check(instr_is_branch_to_addr(iptr, addr - 0x8000));
-
- /* All condition code bits set & link */
- flags = 0x3ff000 | BRANCH_SET_LINK;
-
- /* Branch to self */
- err = create_cond_branch(&instr, iptr, addr, flags);
- patch_instruction(iptr, instr);
- check(instr_is_branch_to_addr(iptr, addr));
-
- /* Branch to self - 0x100 */
- err = create_cond_branch(&instr, iptr, addr - 0x100, flags);
- patch_instruction(iptr, instr);
- check(instr_is_branch_to_addr(iptr, addr - 0x100));
-
- /* Branch to self + 0x100 */
- err = create_cond_branch(&instr, iptr, addr + 0x100, flags);
- patch_instruction(iptr, instr);
- check(instr_is_branch_to_addr(iptr, addr + 0x100));
-
- /* Maximum relative negative offset, - 32 KB */
- err = create_cond_branch(&instr, iptr, addr - 0x8000, flags);
- patch_instruction(iptr, instr);
- check(instr_is_branch_to_addr(iptr, addr - 0x8000));
-
- /* Out of range relative negative offset, - 32 KB + 4*/
- err = create_cond_branch(&instr, iptr, addr - 0x8004, flags);
- check(err);
-
- /* Out of range relative positive offset, + 32 KB */
- err = create_cond_branch(&instr, iptr, addr + 0x8000, flags);
- check(err);
-
- /* Unaligned target */
- err = create_cond_branch(&instr, iptr, addr + 3, flags);
- check(err);
-
- /* Check flags are masked correctly */
- err = create_cond_branch(&instr, iptr, addr, 0xFFFFFFFC);
- patch_instruction(iptr, instr);
- check(instr_is_branch_to_addr(iptr, addr));
- check(ppc_inst_equal(instr, ppc_inst(0x43FF0000)));
-}
-
-static void __init test_translate_branch(void)
-{
- unsigned long addr;
- void *p, *q;
- struct ppc_inst instr;
- void *buf;
-
- buf = vmalloc(PAGE_ALIGN(0x2000000 + 1));
- check(buf);
- if (!buf)
- return;
-
- /* Simple case, branch to self moved a little */
- p = buf;
- addr = (unsigned long)p;
- patch_branch(p, addr, 0);
- check(instr_is_branch_to_addr(p, addr));
- q = p + 4;
- translate_branch(&instr, q, p);
- patch_instruction(q, instr);
- check(instr_is_branch_to_addr(q, addr));
-
- /* Maximum negative case, move b . to addr + 32 MB */
- p = buf;
- addr = (unsigned long)p;
- patch_branch(p, addr, 0);
- q = buf + 0x2000000;
- translate_branch(&instr, q, p);
- patch_instruction(q, instr);
- check(instr_is_branch_to_addr(p, addr));
- check(instr_is_branch_to_addr(q, addr));
- check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x4a000000)));
-
- /* Maximum positive case, move x to x - 32 MB + 4 */
- p = buf + 0x2000000;
- addr = (unsigned long)p;
- patch_branch(p, addr, 0);
- q = buf + 4;
- translate_branch(&instr, q, p);
- patch_instruction(q, instr);
- check(instr_is_branch_to_addr(p, addr));
- check(instr_is_branch_to_addr(q, addr));
- check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x49fffffc)));
-
- /* Jump to x + 16 MB moved to x + 20 MB */
- p = buf;
- addr = 0x1000000 + (unsigned long)buf;
- patch_branch(p, addr, BRANCH_SET_LINK);
- q = buf + 0x1400000;
- translate_branch(&instr, q, p);
- patch_instruction(q, instr);
- check(instr_is_branch_to_addr(p, addr));
- check(instr_is_branch_to_addr(q, addr));
-
- /* Jump to x + 16 MB moved to x - 16 MB + 4 */
- p = buf + 0x1000000;
- addr = 0x2000000 + (unsigned long)buf;
- patch_branch(p, addr, 0);
- q = buf + 4;
- translate_branch(&instr, q, p);
- patch_instruction(q, instr);
- check(instr_is_branch_to_addr(p, addr));
- check(instr_is_branch_to_addr(q, addr));
-
-
- /* Conditional branch tests */
-
- /* Simple case, branch to self moved a little */
- p = buf;
- addr = (unsigned long)p;
- create_cond_branch(&instr, p, addr, 0);
- patch_instruction(p, instr);
- check(instr_is_branch_to_addr(p, addr));
- q = buf + 4;
- translate_branch(&instr, q, p);
- patch_instruction(q, instr);
- check(instr_is_branch_to_addr(q, addr));
-
- /* Maximum negative case, move b . to addr + 32 KB */
- p = buf;
- addr = (unsigned long)p;
- create_cond_branch(&instr, p, addr, 0xFFFFFFFC);
- patch_instruction(p, instr);
- q = buf + 0x8000;
- translate_branch(&instr, q, p);
- patch_instruction(q, instr);
- check(instr_is_branch_to_addr(p, addr));
- check(instr_is_branch_to_addr(q, addr));
- check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x43ff8000)));
-
- /* Maximum positive case, move x to x - 32 KB + 4 */
- p = buf + 0x8000;
- addr = (unsigned long)p;
- create_cond_branch(&instr, p, addr, 0xFFFFFFFC);
- patch_instruction(p, instr);
- q = buf + 4;
- translate_branch(&instr, q, p);
- patch_instruction(q, instr);
- check(instr_is_branch_to_addr(p, addr));
- check(instr_is_branch_to_addr(q, addr));
- check(ppc_inst_equal(ppc_inst_read(q), ppc_inst(0x43ff7ffc)));
-
- /* Jump to x + 12 KB moved to x + 20 KB */
- p = buf;
- addr = 0x3000 + (unsigned long)buf;
- create_cond_branch(&instr, p, addr, BRANCH_SET_LINK);
- patch_instruction(p, instr);
- q = buf + 0x5000;
- translate_branch(&instr, q, p);
- patch_instruction(q, instr);
- check(instr_is_branch_to_addr(p, addr));
- check(instr_is_branch_to_addr(q, addr));
-
- /* Jump to x + 8 KB moved to x - 8 KB + 4 */
- p = buf + 0x2000;
- addr = 0x4000 + (unsigned long)buf;
- create_cond_branch(&instr, p, addr, 0);
- patch_instruction(p, instr);
- q = buf + 4;
- translate_branch(&instr, q, p);
- patch_instruction(q, instr);
- check(instr_is_branch_to_addr(p, addr));
- check(instr_is_branch_to_addr(q, addr));
-
- /* Free the buffer we were using */
- vfree(buf);
-}
-
-#ifdef CONFIG_PPC64
-static void __init test_prefixed_patching(void)
-{
- extern unsigned int code_patching_test1[];
- extern unsigned int code_patching_test1_expected[];
- extern unsigned int end_code_patching_test1[];
-
- __patch_instruction(code_patching_test1,
- ppc_inst_prefix(OP_PREFIX << 26, 0x00000000),
- code_patching_test1);
-
- check(!memcmp(code_patching_test1,
- code_patching_test1_expected,
- sizeof(unsigned int) *
- (end_code_patching_test1 - code_patching_test1)));
-}
-#else
-static inline void test_prefixed_patching(void) {}
-#endif
-
-static int __init test_code_patching(void)
-{
- printk(KERN_DEBUG "Running code patching self-tests ...\n");
-
- test_branch_iform();
- test_branch_bform();
- test_create_function_call();
- test_translate_branch();
- test_prefixed_patching();
-
- return 0;
-}
-late_initcall(test_code_patching);
-
-#endif /* CONFIG_CODE_PATCHING_SELFTEST */