diff options
Diffstat (limited to 'arch/powerpc/lib/code-patching.c')
| -rw-r--r-- | arch/powerpc/lib/code-patching.c | 298 |
1 files changed, 298 insertions, 0 deletions
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c index 27957c4ea9e0..0559fe086eb4 100644 --- a/arch/powerpc/lib/code-patching.c +++ b/arch/powerpc/lib/code-patching.c @@ -8,6 +8,9 @@ */ #include <linux/kernel.h> +#include <linux/vmalloc.h> +#include <linux/init.h> +#include <asm/page.h> #include <asm/code-patching.h> @@ -148,3 +151,298 @@ unsigned int translate_branch(const unsigned int *dest, const unsigned int *src) return 0; } + + +#ifdef CONFIG_CODE_PATCHING_SELFTEST + +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) +{ + unsigned int instr; + unsigned long addr; + + addr = (unsigned long)&instr; + + /* The simplest case, branch to self, no flags */ + check(instr_is_branch_iform(0x48000000)); + /* All bits of target set, and flags */ + check(instr_is_branch_iform(0x4bffffff)); + /* High bit of opcode set, which is wrong */ + check(!instr_is_branch_iform(0xcbffffff)); + /* Middle bits of opcode set, which is wrong */ + check(!instr_is_branch_iform(0x7bffffff)); + + /* Simplest case, branch to self with link */ + check(instr_is_branch_iform(0x48000001)); + /* All bits of targets set */ + check(instr_is_branch_iform(0x4bfffffd)); + /* Some bits of targets set */ + check(instr_is_branch_iform(0x4bff00fd)); + /* Must be a valid branch to start with */ + check(!instr_is_branch_iform(0x7bfffffd)); + + /* Absolute branch to 0x100 */ + instr = 0x48000103; + check(instr_is_branch_to_addr(&instr, 0x100)); + /* Absolute branch to 0x420fc */ + instr = 0x480420ff; + check(instr_is_branch_to_addr(&instr, 0x420fc)); + /* Maximum positive relative branch, + 20MB - 4B */ + instr = 0x49fffffc; + check(instr_is_branch_to_addr(&instr, addr + 0x1FFFFFC)); + /* Smallest negative relative branch, - 4B */ + instr = 0x4bfffffc; + check(instr_is_branch_to_addr(&instr, addr - 4)); + /* Largest negative relative branch, - 32 MB */ + instr = 0x4a000000; + check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); + + /* Branch to self, with link */ + instr = create_branch(&instr, addr, BRANCH_SET_LINK); + check(instr_is_branch_to_addr(&instr, addr)); + + /* Branch to self - 0x100, with link */ + instr = create_branch(&instr, addr - 0x100, BRANCH_SET_LINK); + check(instr_is_branch_to_addr(&instr, addr - 0x100)); + + /* Branch to self + 0x100, no link */ + instr = create_branch(&instr, addr + 0x100, 0); + check(instr_is_branch_to_addr(&instr, addr + 0x100)); + + /* Maximum relative negative offset, - 32 MB */ + instr = create_branch(&instr, addr - 0x2000000, BRANCH_SET_LINK); + check(instr_is_branch_to_addr(&instr, addr - 0x2000000)); + + /* Out of range relative negative offset, - 32 MB + 4*/ + instr = create_branch(&instr, addr - 0x2000004, BRANCH_SET_LINK); + check(instr == 0); + + /* Out of range relative positive offset, + 32 MB */ + instr = create_branch(&instr, addr + 0x2000000, BRANCH_SET_LINK); + check(instr == 0); + + /* Unaligned target */ + instr = create_branch(&instr, addr + 3, BRANCH_SET_LINK); + check(instr == 0); + + /* Check flags are masked correctly */ + instr = create_branch(&instr, addr, 0xFFFFFFFC); + check(instr_is_branch_to_addr(&instr, addr)); + check(instr == 0x48000000); +} + +static void __init test_create_function_call(void) +{ + unsigned int *iptr; + unsigned long dest; + + /* Check we can create a function call */ + iptr = (unsigned int *)ppc_function_entry(test_trampoline); + dest = ppc_function_entry(test_create_function_call); + patch_instruction(iptr, create_branch(iptr, dest, BRANCH_SET_LINK)); + check(instr_is_branch_to_addr(iptr, dest)); +} + +static void __init test_branch_bform(void) +{ + unsigned long addr; + unsigned int *iptr, instr, flags; + + iptr = &instr; + addr = (unsigned long)iptr; + + /* The simplest case, branch to self, no flags */ + check(instr_is_branch_bform(0x40000000)); + /* All bits of target set, and flags */ + check(instr_is_branch_bform(0x43ffffff)); + /* High bit of opcode set, which is wrong */ + check(!instr_is_branch_bform(0xc3ffffff)); + /* Middle bits of opcode set, which is wrong */ + check(!instr_is_branch_bform(0x7bffffff)); + + /* Absolute conditional branch to 0x100 */ + instr = 0x43ff0103; + check(instr_is_branch_to_addr(&instr, 0x100)); + /* Absolute conditional branch to 0x20fc */ + instr = 0x43ff20ff; + check(instr_is_branch_to_addr(&instr, 0x20fc)); + /* Maximum positive relative conditional branch, + 32 KB - 4B */ + instr = 0x43ff7ffc; + check(instr_is_branch_to_addr(&instr, addr + 0x7FFC)); + /* Smallest negative relative conditional branch, - 4B */ + instr = 0x43fffffc; + check(instr_is_branch_to_addr(&instr, addr - 4)); + /* Largest negative relative conditional branch, - 32 KB */ + instr = 0x43ff8000; + check(instr_is_branch_to_addr(&instr, addr - 0x8000)); + + /* All condition code bits set & link */ + flags = 0x3ff000 | BRANCH_SET_LINK; + + /* Branch to self */ + instr = create_cond_branch(iptr, addr, flags); + check(instr_is_branch_to_addr(&instr, addr)); + + /* Branch to self - 0x100 */ + instr = create_cond_branch(iptr, addr - 0x100, flags); + check(instr_is_branch_to_addr(&instr, addr - 0x100)); + + /* Branch to self + 0x100 */ + instr = create_cond_branch(iptr, addr + 0x100, flags); + check(instr_is_branch_to_addr(&instr, addr + 0x100)); + + /* Maximum relative negative offset, - 32 KB */ + instr = create_cond_branch(iptr, addr - 0x8000, flags); + check(instr_is_branch_to_addr(&instr, addr - 0x8000)); + + /* Out of range relative negative offset, - 32 KB + 4*/ + instr = create_cond_branch(iptr, addr - 0x8004, flags); + check(instr == 0); + + /* Out of range relative positive offset, + 32 KB */ + instr = create_cond_branch(iptr, addr + 0x8000, flags); + check(instr == 0); + + /* Unaligned target */ + instr = create_cond_branch(iptr, addr + 3, flags); + check(instr == 0); + + /* Check flags are masked correctly */ + instr = create_cond_branch(iptr, addr, 0xFFFFFFFC); + check(instr_is_branch_to_addr(&instr, addr)); + check(instr == 0x43FF0000); +} + +static void __init test_translate_branch(void) +{ + unsigned long addr; + unsigned int *p, *q; + 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 + 1; + patch_instruction(q, translate_branch(q, p)); + 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; + patch_instruction(q, translate_branch(q, p)); + check(instr_is_branch_to_addr(p, addr)); + check(instr_is_branch_to_addr(q, addr)); + check(*q == 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; + patch_instruction(q, translate_branch(q, p)); + check(instr_is_branch_to_addr(p, addr)); + check(instr_is_branch_to_addr(q, addr)); + check(*q == 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; + patch_instruction(q, translate_branch(q, p)); + 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; + patch_instruction(q, translate_branch(q, p)); + 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; + patch_instruction(p, create_cond_branch(p, addr, 0)); + check(instr_is_branch_to_addr(p, addr)); + q = p + 1; + patch_instruction(q, translate_branch(q, p)); + check(instr_is_branch_to_addr(q, addr)); + + /* Maximum negative case, move b . to addr + 32 KB */ + p = buf; + addr = (unsigned long)p; + patch_instruction(p, create_cond_branch(p, addr, 0xFFFFFFFC)); + q = buf + 0x8000; + patch_instruction(q, translate_branch(q, p)); + check(instr_is_branch_to_addr(p, addr)); + check(instr_is_branch_to_addr(q, addr)); + check(*q == 0x43ff8000); + + /* Maximum positive case, move x to x - 32 KB + 4 */ + p = buf + 0x8000; + addr = (unsigned long)p; + patch_instruction(p, create_cond_branch(p, addr, 0xFFFFFFFC)); + q = buf + 4; + patch_instruction(q, translate_branch(q, p)); + check(instr_is_branch_to_addr(p, addr)); + check(instr_is_branch_to_addr(q, addr)); + check(*q == 0x43ff7ffc); + + /* Jump to x + 12 KB moved to x + 20 KB */ + p = buf; + addr = 0x3000 + (unsigned long)buf; + patch_instruction(p, create_cond_branch(p, addr, BRANCH_SET_LINK)); + q = buf + 0x5000; + patch_instruction(q, translate_branch(q, p)); + 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; + patch_instruction(p, create_cond_branch(p, addr, 0)); + q = buf + 4; + patch_instruction(q, translate_branch(q, p)); + 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 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(); + + return 0; +} +late_initcall(test_code_patching); + +#endif /* CONFIG_CODE_PATCHING_SELFTEST */ |