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authorChristophe Leroy <christophe.leroy@csgroup.eu>2021-12-02 15:00:26 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2021-12-23 14:36:58 +0300
commitf30a578d7653f7dbb253a20daad4bcd9f881d6c9 (patch)
tree5d101c3e2c787447d9d98932781351cf527035ea /arch/powerpc/lib
parent31acc599564120fa41f9df2c567842d003728dab (diff)
downloadlinux-f30a578d7653f7dbb253a20daad4bcd9f881d6c9.tar.xz
powerpc/code-patching: Move code patching selftests in its own file
Code patching selftests are half of code-patching.c. As they are guarded by CONFIG_CODE_PATCHING_SELFTESTS, they'd be better in their own file. Also add a missing __init for instr_is_branch_to_addr() Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/c0c30504f04eb546a48ff77127a8bccd12a3d809.1638446239.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc/lib')
-rw-r--r--arch/powerpc/lib/Makefile2
-rw-r--r--arch/powerpc/lib/code-patching.c355
-rw-r--r--arch/powerpc/lib/test-code-patching.c357
3 files changed, 359 insertions, 355 deletions
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index c2654894b468..3e183f4b4bda 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -21,6 +21,8 @@ endif
obj-y += alloc.o code-patching.o feature-fixups.o pmem.o
+obj-$(CONFIG_CODE_PATCHING_SELFTEST) += test-code-patching.o
+
ifndef CONFIG_KASAN
obj-y += string.o memcmp_$(BITS).o
obj-$(CONFIG_PPC32) += strlen_32.o
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index e24a4b0ce877..906d43463366 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -3,13 +3,10 @@
* 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>
@@ -354,355 +351,3 @@ int translate_branch(ppc_inst_t *instr, const u32 *dest, const u32 *src)
return 1;
}
-
-#ifdef CONFIG_CODE_PATCHING_SELFTEST
-
-static int __init 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;nop;\n");
-}
-
-#define check(x) do { \
- if (!(x)) \
- pr_err("code-patching: test failed at line %d\n", __LINE__); \
-} while (0)
-
-static void __init test_branch_iform(void)
-{
- int err;
- ppc_inst_t 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;
- ppc_inst_t 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;
- ppc_inst_t 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;
- ppc_inst_t 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);
-}
-
-static void __init test_prefixed_patching(void)
-{
- u32 *iptr = (u32 *)ppc_function_entry(test_trampoline);
- u32 expected[2] = {OP_PREFIX << 26, 0};
- ppc_inst_t inst = ppc_inst_prefix(OP_PREFIX << 26, 0);
-
- if (!IS_ENABLED(CONFIG_PPC64))
- return;
-
- patch_instruction(iptr, inst);
-
- check(!memcmp(iptr, expected, sizeof(expected)));
-}
-
-static int __init test_code_patching(void)
-{
- pr_info("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 */
diff --git a/arch/powerpc/lib/test-code-patching.c b/arch/powerpc/lib/test-code-patching.c
new file mode 100644
index 000000000000..e358c9d8a03e
--- /dev/null
+++ b/arch/powerpc/lib/test-code-patching.c
@@ -0,0 +1,357 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2008 Michael Ellerman, IBM Corporation.
+ */
+
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+
+#include <asm/code-patching.h>
+
+static int __init 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;nop;\n");
+}
+
+#define check(x) do { \
+ if (!(x)) \
+ pr_err("code-patching: test failed at line %d\n", __LINE__); \
+} while (0)
+
+static void __init test_branch_iform(void)
+{
+ int err;
+ ppc_inst_t 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;
+ ppc_inst_t 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;
+ ppc_inst_t 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;
+ ppc_inst_t 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);
+}
+
+static void __init test_prefixed_patching(void)
+{
+ u32 *iptr = (u32 *)ppc_function_entry(test_trampoline);
+ u32 expected[2] = {OP_PREFIX << 26, 0};
+ ppc_inst_t inst = ppc_inst_prefix(OP_PREFIX << 26, 0);
+
+ if (!IS_ENABLED(CONFIG_PPC64))
+ return;
+
+ patch_instruction(iptr, inst);
+
+ check(!memcmp(iptr, expected, sizeof(expected)));
+}
+
+static int __init test_code_patching(void)
+{
+ pr_info("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);