From: novafacing <rowanbh...@gmail.com> Signed-off-by: novafacing <rowanbh...@gmail.com> Signed-off-by: Rowan Hart <rowanbh...@gmail.com> --- tests/tcg/Makefile.target | 1 + tests/tcg/plugins/meson.build | 2 +- tests/tcg/plugins/patch.c | 324 ++++++++++++++++++++++ tests/tcg/x86_64/Makefile.softmmu-target | 32 ++- tests/tcg/x86_64/system/patch-target.c | 32 +++ tests/tcg/x86_64/system/validate-patch.py | 39 +++ 6 files changed, 424 insertions(+), 6 deletions(-) create mode 100644 tests/tcg/plugins/patch.c create mode 100644 tests/tcg/x86_64/system/patch-target.c create mode 100755 tests/tcg/x86_64/system/validate-patch.py
diff --git a/tests/tcg/Makefile.target b/tests/tcg/Makefile.target index 95ff76ea44..4b709a9d18 100644 --- a/tests/tcg/Makefile.target +++ b/tests/tcg/Makefile.target @@ -176,6 +176,7 @@ RUN_TESTS+=$(EXTRA_RUNS) # Some plugins need additional arguments above the default to fully # exercise things. We can define them on a per-test basis here. run-plugin-%-with-libmem.so: PLUGIN_ARGS=$(COMMA)inline=true +run-plugin-%-with-libpatch.so: PLUGIN_ARGS=$(COMMA)target=ffffffff$(COMMA)patch=00000000 ifeq ($(filter %-softmmu, $(TARGET)),) run-%: % diff --git a/tests/tcg/plugins/meson.build b/tests/tcg/plugins/meson.build index 41f02f2c7f..163042e601 100644 --- a/tests/tcg/plugins/meson.build +++ b/tests/tcg/plugins/meson.build @@ -1,6 +1,6 @@ t = [] if get_option('plugins') - foreach i : ['bb', 'empty', 'inline', 'insn', 'mem', 'reset', 'syscall'] + foreach i : ['bb', 'empty', 'inline', 'insn', 'mem', 'reset', 'syscall', 'patch'] if host_os == 'windows' t += shared_module(i, files(i + '.c') + '../../../contrib/plugins/win32_linker.c', include_directories: '../../../include/qemu', diff --git a/tests/tcg/plugins/patch.c b/tests/tcg/plugins/patch.c new file mode 100644 index 0000000000..6f2bc3688e --- /dev/null +++ b/tests/tcg/plugins/patch.c @@ -0,0 +1,324 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * Copyright (C) 2025, Rowan Hart <rowanbh...@gmail.com> + * + * License: GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + * This plugin patches instructions matching a pattern to a different + * instruction as they execute + * + */ + +#include "glib.h" +#include "glibconfig.h" + +#include <qemu-plugin.h> +#include <string.h> +#include <stdio.h> + +QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION; + +static bool use_hwaddr; +static bool debug_insns; +static GByteArray *target_data; +static GByteArray *patch_data; + +/** + * Parse a string of hexadecimal digits into a GByteArray. The string must be + * even length + */ +static GByteArray *str_to_bytes(const char *str) +{ + GByteArray *bytes = g_byte_array_new(); + char byte[3] = {0}; + size_t len = strlen(str); + guint8 value = 0; + + if (len % 2 != 0) { + g_byte_array_free(bytes, true); + return NULL; + } + + for (size_t i = 0; i < len; i += 2) { + byte[0] = str[i]; + byte[1] = str[i + 1]; + value = (guint8)g_ascii_strtoull(byte, NULL, 16); + g_byte_array_append(bytes, &value, 1); + } + + return bytes; +} + +static void patch_hwaddr(unsigned int vcpu_index, void *userdata) +{ + uint64_t addr = (uint64_t)userdata; + GString *str = g_string_new(NULL); + g_string_printf(str, "patching: @0x%" + PRIx64 "\n", + addr); + qemu_plugin_outs(str->str); + g_string_free(str, true); + + struct qemu_plugin_address_space_info *info = + qemu_plugin_get_current_vcpu_address_spaces(); + + if (!info) { + qemu_plugin_outs("Failed to get address spaces\n"); + return; + } + + qemu_plugin_outs("Got address spaces\n"); + + int n_address_spaces = qemu_plugin_n_address_spaces(info); + unsigned int memory_idx; + + for (memory_idx = 0; memory_idx < n_address_spaces; memory_idx++) { + const char *name = qemu_plugin_address_space_name(info, memory_idx); + if (!g_strcmp0(name, "cpu-memory-0")) { + break; + } + } + + if (memory_idx >= n_address_spaces) { + qemu_plugin_outs("No matching address space\n"); + return; + } + + qemu_plugin_outs("Got address space cpu-memory-0\n"); + + qemu_plugin_outs("Writing memory (hwaddr)...\n"); + enum qemu_plugin_hwaddr_operation_result result = + qemu_plugin_write_memory_hwaddr(memory_idx, addr, patch_data); + + + if (result != QEMU_PLUGIN_HWADDR_OPERATION_OK) { + GString *errmsg = g_string_new(NULL); + g_string_printf(errmsg, "Failed to write memory: %d\n", result); + qemu_plugin_outs(errmsg->str); + g_string_free(errmsg, true); + return; + } + + GByteArray *read_data = g_byte_array_new(); + + result = qemu_plugin_read_memory_hwaddr(memory_idx, addr, read_data, patch_data->len); + + qemu_plugin_outs("Reading memory...\n"); + + if (result != QEMU_PLUGIN_HWADDR_OPERATION_OK) { + GString *errmsg = g_string_new(NULL); + g_string_printf(errmsg, "Failed to read memory: %d\n", result); + qemu_plugin_outs(errmsg->str); + g_string_free(errmsg, true); + return; + } + + if (memcmp(patch_data->data, read_data->data, patch_data->len) != 0) { + qemu_plugin_outs("Failed to read back written data\n"); + } + + qemu_plugin_outs("Success!\n"); + + return; +} + +static void patch_vaddr(unsigned int vcpu_index, void *userdata) +{ + uint64_t addr = (uint64_t)userdata; + GString *str = g_string_new(NULL); + g_string_printf(str, "patching: @0x%" + PRIx64 "\n", + addr); + qemu_plugin_outs(str->str); + g_string_free(str, true); + + qemu_plugin_outs("Writing memory (vaddr)...\n"); + + if (!qemu_plugin_write_memory_vaddr(addr, patch_data)) { + qemu_plugin_outs("Failed to write memory\n"); + return; + } + + qemu_plugin_outs("Reading memory (vaddr)...\n"); + + + GByteArray *read_data = g_byte_array_new(); + + if (!qemu_plugin_read_memory_vaddr(addr, read_data, patch_data->len)) { + qemu_plugin_outs("Failed to read memory\n"); + return; + } + + if (memcmp(patch_data->data, read_data->data, patch_data->len) != 0) { + qemu_plugin_outs("Failed to read back written data\n"); + } + + qemu_plugin_outs("Success!\n"); + + return; +} + +static void debug_disas(unsigned int vcpu_index, void *userdata) +{ + GString *debug_info = (GString *)userdata; + qemu_plugin_outs(debug_info->str); +} + +static void debug_print_newline(unsigned int vcpu_index, void *userdata) +{ + qemu_plugin_outs("\n"); +} + +/* + * Callback on translation of a translation block. + */ +static void vcpu_tb_trans_cb(qemu_plugin_id_t id, struct qemu_plugin_tb *tb) +{ + uint64_t addr = 0; + GByteArray *insn_data = g_byte_array_new(); + for (size_t i = 0; i < qemu_plugin_tb_n_insns(tb); i++) { + struct qemu_plugin_insn *insn = qemu_plugin_tb_get_insn(tb, i); + + if (use_hwaddr) { + uint64_t vaddr = qemu_plugin_insn_vaddr(insn); + if (!qemu_plugin_translate_vaddr(vaddr, &addr)) { + qemu_plugin_outs("Failed to translate vaddr\n"); + continue; + } + } else { + addr = qemu_plugin_insn_vaddr(insn); + } + + g_byte_array_set_size(insn_data, qemu_plugin_insn_size(insn)); + qemu_plugin_insn_data(insn, insn_data->data, insn_data->len); + + if (insn_data->len >= target_data->len && + !memcmp(insn_data->data, target_data->data, + MIN(target_data->len, insn_data->len))) { + if (use_hwaddr) { + qemu_plugin_register_vcpu_tb_exec_cb(tb, patch_hwaddr, + QEMU_PLUGIN_CB_NO_REGS, + (void *)addr); + } else { + qemu_plugin_register_vcpu_tb_exec_cb(tb, patch_vaddr, + QEMU_PLUGIN_CB_NO_REGS, + (void *)addr); + } + } + } + for (size_t i = 0; i < qemu_plugin_tb_n_insns(tb); i++) { + struct qemu_plugin_insn *insn = qemu_plugin_tb_get_insn(tb, i); + uint64_t vaddr = qemu_plugin_insn_vaddr(insn); + uint64_t hwaddr = (uint64_t)qemu_plugin_insn_haddr(insn); + uint64_t translated_hwaddr = 0; + if (!qemu_plugin_translate_vaddr(vaddr, &translated_hwaddr)) { + qemu_plugin_outs("Failed to translate vaddr\n"); + continue; + } + char *disas = qemu_plugin_insn_disas(insn); + GString *str = g_string_new(NULL); + g_string_printf(str, + "vaddr: 0x%" PRIx64 " hwaddr: 0x%" PRIx64 + " translated: 0x%" PRIx64 " : %s\n", + vaddr, hwaddr, translated_hwaddr, disas); + g_free(disas); + if (debug_insns) { + qemu_plugin_register_vcpu_insn_exec_cb(insn, debug_disas, + QEMU_PLUGIN_CB_NO_REGS, + str); + } + + } + + if (debug_insns) { + qemu_plugin_register_vcpu_tb_exec_cb(tb, debug_print_newline, + QEMU_PLUGIN_CB_NO_REGS, + NULL); + } + + g_byte_array_free(insn_data, true); +} + +static void usage(void) +{ + fprintf(stderr, "Usage: <lib>,target=<target>,patch=<patch>" + "[,use_hwaddr=<use_hwaddr>]" + "[,debug_insns=<debug_insns>]\n"); +} + +/* + * Called when the plugin is installed + */ +QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id, + const qemu_info_t *info, int argc, + char **argv) +{ + + use_hwaddr = true; + debug_insns = false; + target_data = NULL; + patch_data = NULL; + + if (argc > 4) { + usage(); + return -1; + } + + for (size_t i = 0; i < argc; i++) { + char *opt = argv[i]; + g_auto(GStrv) tokens = g_strsplit(opt, "=", 2); + if (g_strcmp0(tokens[0], "use_hwaddr") == 0) { + if (!qemu_plugin_bool_parse(tokens[0], tokens[1], &use_hwaddr)) { + fprintf(stderr, + "Failed to parse boolean argument use_hwaddr\n"); + return -1; + } + } else if (g_strcmp0(tokens[0], "debug_insns") == 0) { + if (!qemu_plugin_bool_parse(tokens[0], tokens[1], &debug_insns)) { + fprintf(stderr, + "Failed to parse boolean argument debug_insns\n"); + return -1; + } + } else if (g_strcmp0(tokens[0], "target") == 0) { + target_data = str_to_bytes(tokens[1]); + if (!target_data) { + fprintf(stderr, + "Failed to parse target bytes.\n"); + return -1; + } + } else if (g_strcmp0(tokens[0], "patch") == 0) { + patch_data = str_to_bytes(tokens[1]); + if (!patch_data) { + fprintf(stderr, "Failed to parse patch bytes.\n"); + return -1; + } + } else { + fprintf(stderr, "Unknown argument: %s\n", tokens[0]); + usage(); + return -1; + } + } + + if (!target_data) { + fprintf(stderr, "target argument is required\n"); + usage(); + return -1; + } + + if (!patch_data) { + fprintf(stderr, "patch argument is required\n"); + usage(); + return -1; + } + + if (target_data->len != patch_data->len) { + fprintf(stderr, "Target and patch data must be the same length\n"); + return -1; + } + + qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans_cb); + + return 0; +} diff --git a/tests/tcg/x86_64/Makefile.softmmu-target b/tests/tcg/x86_64/Makefile.softmmu-target index ef6bcb4dc7..8d3a067c33 100644 --- a/tests/tcg/x86_64/Makefile.softmmu-target +++ b/tests/tcg/x86_64/Makefile.softmmu-target @@ -7,18 +7,27 @@ # I386_SYSTEM_SRC=$(SRC_PATH)/tests/tcg/i386/system -X64_SYSTEM_SRC=$(SRC_PATH)/tests/tcg/x86_64/system +X86_64_SYSTEM_SRC=$(SRC_PATH)/tests/tcg/x86_64/system # These objects provide the basic boot code and helper functions for all tests CRT_OBJS=boot.o -CRT_PATH=$(X64_SYSTEM_SRC) -LINK_SCRIPT=$(X64_SYSTEM_SRC)/kernel.ld +X86_64_TEST_C_SRCS=$(wildcard $(X86_64_SYSTEM_SRC)/*.c) +X86_64_TEST_S_SRCS= + +X86_64_C_TESTS = $(patsubst $(X86_64_SYSTEM_SRC)/%.c, %, $(X86_64_TEST_C_SRCS)) +X86_64_S_TESTS = $(patsubst $(X86_64_SYSTEM_SRC)/%.S, %, $(X86_64_TEST_S_SRCS)) + +X86_64_TESTS = $(X86_64_C_TESTS) +X86_64_TESTS += $(X86_64_S_TESTS) + +CRT_PATH=$(X86_64_SYSTEM_SRC) +LINK_SCRIPT=$(X86_64_SYSTEM_SRC)/kernel.ld LDFLAGS=-Wl,-T$(LINK_SCRIPT) -Wl,-melf_x86_64 CFLAGS+=-nostdlib -ggdb -O0 $(MINILIB_INC) LDFLAGS+=-static -nostdlib $(CRT_OBJS) $(MINILIB_OBJS) -lgcc -TESTS+=$(MULTIARCH_TESTS) +TESTS+=$(X86_64_TESTS) $(MULTIARCH_TESTS) EXTRA_RUNS+=$(MULTIARCH_RUNS) # building head blobs @@ -27,11 +36,24 @@ EXTRA_RUNS+=$(MULTIARCH_RUNS) %.o: $(CRT_PATH)/%.S $(CC) $(CFLAGS) $(EXTRA_CFLAGS) -Wa,--noexecstack -c $< -o $@ -# Build and link the tests +# Build and link the multiarch tests %: %.c $(LINK_SCRIPT) $(CRT_OBJS) $(MINILIB_OBJS) $(CC) $(CFLAGS) $(EXTRA_CFLAGS) $< -o $@ $(LDFLAGS) +# Build and link the arch tests +%: $(X86_64_SYSTEM_SRC)/%.c $(LINK_SCRIPT) $(CRT_OBJS) $(MINILIB_OBJS) + $(CC) $(CFLAGS) $(EXTRA_CFLAGS) $< -o $@ $(LDFLAGS) + memory: CFLAGS+=-DCHECK_UNALIGNED=1 +patch-target: CFLAGS+=-O0 # Running QEMU_OPTS+=-device isa-debugcon,chardev=output -device isa-debug-exit,iobase=0xf4,iosize=0x4 -kernel + +# Add patch-target to ADDITIONAL_PLUGINS_TESTS +ADDITIONAL_PLUGINS_TESTS += patch-target + +run-plugin-patch-target-with-libpatch.so: \ + PLUGIN_ARGS=$(COMMA)target=ffc0$(COMMA)patch=9090$(COMMA)use_hwaddr=true$(COMMA)debug_insns=false +run-plugin-patch-target-with-libpatch.so: \ + CHECK_PLUGIN_OUTPUT_COMMAND=$(X86_64_SYSTEM_SRC)/validate-patch.py $@.out \ No newline at end of file diff --git a/tests/tcg/x86_64/system/patch-target.c b/tests/tcg/x86_64/system/patch-target.c new file mode 100644 index 0000000000..671987a873 --- /dev/null +++ b/tests/tcg/x86_64/system/patch-target.c @@ -0,0 +1,32 @@ +/* + * SPDX-License-Identifier: GPL-2.0-or-later + * + * Copyright (C) 2025, Rowan Hart <rowanbh...@gmail.com> + * + * License: GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + * This test target increments a value 100 times. The patcher converts the + * inc instruction to a nop, so it only increments the value once. + * + */ +#include <minilib.h> + +int main(void) +{ + ml_printf("Running test...\n"); +#if defined(__x86_64__) + ml_printf("Testing insn memory read/write...\n"); + unsigned int x = 0; + for (int i = 0; i < 100; i++) { + asm volatile ( + "inc %[x]" + : [x] "+a" (x) + ); + } + ml_printf("Value: %d\n", x); +#else + #error "This test is only valid for x86_64 architecture." +#endif + return 0; +} diff --git a/tests/tcg/x86_64/system/validate-patch.py b/tests/tcg/x86_64/system/validate-patch.py new file mode 100755 index 0000000000..700950eae5 --- /dev/null +++ b/tests/tcg/x86_64/system/validate-patch.py @@ -0,0 +1,39 @@ +#!/usr/bin/env python3 +# +# validate-patch.py: check the patch applies +# +# This program takes two inputs: +# - the plugin output +# - the binary output +# +# Copyright (C) 2024 +# +# SPDX-License-Identifier: GPL-2.0-or-later + +import sys +from argparse import ArgumentParser + +def main() -> None: + """ + Process the arguments, injest the program and plugin out and + verify they match up and report if they do not. + """ + parser = ArgumentParser(description="Validate patch") + parser.add_argument('test_output', + help="The output from the test itself") + parser.add_argument('plugin_output', + help="The output from plugin") + args = parser.parse_args() + + with open(args.test_output, 'r') as f: + test_data = f.read() + with open(args.plugin_output, 'r') as f: + plugin_data = f.read() + if "Value: 1" in test_data: + sys.exit(0) + else: + sys.exit(1) + +if __name__ == "__main__": + main() + -- 2.49.0