diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-14 15:17:26 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-01-14 15:17:26 +0100 |
commit | 29ec39fcf11e4583eb8d5174f756ea109c77cc44 (patch) | |
tree | 656f5c7166efe176ab2c7e24042f4e38a86b4473 /arch/powerpc/lib/test-code-patching.c | |
parent | 3fb561b1e0bf4c75bc5f4d799845b08fa5ab3853 (diff) | |
parent | f1aa0e47c29268776205698f2453dc07fab49855 (diff) |
Merge tag 'powerpc-5.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
- Optimise radix KVM guest entry/exit by 2x on Power9/Power10.
- Allow firmware to tell us whether to disable the entry and uaccess
flushes on Power10 or later CPUs.
- Add BPF_PROBE_MEM support for 32 and 64-bit BPF jits.
- Several fixes and improvements to our hard lockup watchdog.
- Activate HAVE_DYNAMIC_FTRACE_WITH_REGS on 32-bit.
- Allow building the 64-bit Book3S kernel without hash MMU support, ie.
Radix only.
- Add KUAP (SMAP) support for 40x, 44x, 8xx, Book3E (64-bit).
- Add new encodings for perf_mem_data_src.mem_hops field, and use them
on Power10.
- A series of small performance improvements to 64-bit interrupt entry.
- Several commits fixing issues when building with the clang integrated
assembler.
- Many other small features and fixes.
Thanks to Alan Modra, Alexey Kardashevskiy, Ammar Faizi, Anders Roxell,
Arnd Bergmann, Athira Rajeev, Cédric Le Goater, Christophe JAILLET,
Christophe Leroy, Christoph Hellwig, Daniel Axtens, David Yang, Erhard
Furtner, Fabiano Rosas, Greg Kroah-Hartman, Guo Ren, Hari Bathini, Jason
Wang, Joel Stanley, Julia Lawall, Kajol Jain, Kees Cook, Laurent Dufour,
Madhavan Srinivasan, Mark Brown, Minghao Chi, Nageswara R Sastry, Naresh
Kamboju, Nathan Chancellor, Nathan Lynch, Nicholas Piggin, Nick Child,
Oliver O'Halloran, Peiwei Hu, Randy Dunlap, Ravi Bangoria, Rob Herring,
Russell Currey, Sachin Sant, Sean Christopherson, Segher Boessenkool,
Thadeu Lima de Souza Cascardo, Tyrel Datwyler, Xiang wangx, and Yang
Guang.
* tag 'powerpc-5.17-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (240 commits)
powerpc/xmon: Dump XIVE information for online-only processors.
powerpc/opal: use default_groups in kobj_type
powerpc/cacheinfo: use default_groups in kobj_type
powerpc/sched: Remove unused TASK_SIZE_OF
powerpc/xive: Add missing null check after calling kmalloc
powerpc/floppy: Remove usage of the deprecated "pci-dma-compat.h" API
selftests/powerpc: Add a test of sigreturning to an unaligned address
powerpc/64s: Use EMIT_WARN_ENTRY for SRR debug warnings
powerpc/64s: Mask NIP before checking against SRR0
powerpc/perf: Fix spelling of "its"
powerpc/32: Fix boot failure with GCC latent entropy plugin
powerpc/code-patching: Replace patch_instruction() by ppc_inst_write() in selftests
powerpc/code-patching: Move code patching selftests in its own file
powerpc/code-patching: Move instr_is_branch_{i/b}form() in code-patching.h
powerpc/code-patching: Move patch_exception() outside code-patching.c
powerpc/code-patching: Use test_trampoline for prefixed patch test
powerpc/code-patching: Fix patch_branch() return on out-of-range failure
powerpc/code-patching: Reorganise do_patch_instruction() to ease error handling
powerpc/code-patching: Fix unmap_patch_area() error handling
powerpc/code-patching: Fix error handling in do_patch_instruction()
...
Diffstat (limited to 'arch/powerpc/lib/test-code-patching.c')
-rw-r--r-- | arch/powerpc/lib/test-code-patching.c | 362 |
1 files changed, 362 insertions, 0 deletions
diff --git a/arch/powerpc/lib/test-code-patching.c b/arch/powerpc/lib/test-code-patching.c new file mode 100644 index 000000000000..c44823292f73 --- /dev/null +++ b/arch/powerpc/lib/test-code-patching.c @@ -0,0 +1,362 @@ +// 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 */ + ppc_inst_write(iptr, ppc_inst(0x48000103)); + check(instr_is_branch_to_addr(iptr, 0x100)); + /* Absolute branch to 0x420fc */ + ppc_inst_write(iptr, ppc_inst(0x480420ff)); + check(instr_is_branch_to_addr(iptr, 0x420fc)); + /* Maximum positive relative branch, + 20MB - 4B */ + ppc_inst_write(iptr, ppc_inst(0x49fffffc)); + check(instr_is_branch_to_addr(iptr, addr + 0x1FFFFFC)); + /* Smallest negative relative branch, - 4B */ + ppc_inst_write(iptr, ppc_inst(0x4bfffffc)); + check(instr_is_branch_to_addr(iptr, addr - 4)); + /* Largest negative relative branch, - 32 MB */ + ppc_inst_write(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); + ppc_inst_write(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); + ppc_inst_write(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); + ppc_inst_write(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); + ppc_inst_write(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); + ppc_inst_write(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 */ + ppc_inst_write(iptr, ppc_inst(0x43ff0103)); + check(instr_is_branch_to_addr(iptr, 0x100)); + /* Absolute conditional branch to 0x20fc */ + ppc_inst_write(iptr, ppc_inst(0x43ff20ff)); + check(instr_is_branch_to_addr(iptr, 0x20fc)); + /* Maximum positive relative conditional branch, + 32 KB - 4B */ + ppc_inst_write(iptr, ppc_inst(0x43ff7ffc)); + check(instr_is_branch_to_addr(iptr, addr + 0x7FFC)); + /* Smallest negative relative conditional branch, - 4B */ + ppc_inst_write(iptr, ppc_inst(0x43fffffc)); + check(instr_is_branch_to_addr(iptr, addr - 4)); + /* Largest negative relative conditional branch, - 32 KB */ + ppc_inst_write(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); + ppc_inst_write(iptr, instr); + check(instr_is_branch_to_addr(iptr, addr)); + + /* Branch to self - 0x100 */ + err = create_cond_branch(&instr, iptr, addr - 0x100, flags); + ppc_inst_write(iptr, instr); + check(instr_is_branch_to_addr(iptr, addr - 0x100)); + + /* Branch to self + 0x100 */ + err = create_cond_branch(&instr, iptr, addr + 0x100, flags); + ppc_inst_write(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); + ppc_inst_write(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); + ppc_inst_write(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; + create_branch(&instr, p, addr, 0); + ppc_inst_write(p, instr); + check(instr_is_branch_to_addr(p, addr)); + q = p + 4; + translate_branch(&instr, q, p); + ppc_inst_write(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; + create_branch(&instr, p, addr, 0); + ppc_inst_write(p, instr); + q = buf + 0x2000000; + translate_branch(&instr, q, p); + ppc_inst_write(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; + create_branch(&instr, p, addr, 0); + ppc_inst_write(p, instr); + q = buf + 4; + translate_branch(&instr, q, p); + ppc_inst_write(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; + create_branch(&instr, p, addr, BRANCH_SET_LINK); + ppc_inst_write(p, instr); + q = buf + 0x1400000; + translate_branch(&instr, q, p); + ppc_inst_write(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; + create_branch(&instr, p, addr, 0); + ppc_inst_write(p, instr); + q = buf + 4; + translate_branch(&instr, q, p); + ppc_inst_write(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); + ppc_inst_write(p, instr); + check(instr_is_branch_to_addr(p, addr)); + q = buf + 4; + translate_branch(&instr, q, p); + ppc_inst_write(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); + ppc_inst_write(p, instr); + q = buf + 0x8000; + translate_branch(&instr, q, p); + ppc_inst_write(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); + ppc_inst_write(p, instr); + q = buf + 4; + translate_branch(&instr, q, p); + ppc_inst_write(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); + ppc_inst_write(p, instr); + q = buf + 0x5000; + translate_branch(&instr, q, p); + ppc_inst_write(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); + ppc_inst_write(p, instr); + q = buf + 4; + translate_branch(&instr, q, p); + ppc_inst_write(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); |