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fix fxsave fpip value, provide tests

This commit is contained in:
Dimitris Glynos 2023-10-26 08:42:58 +03:00
parent ca65964e78
commit 9d8e639c69
2 changed files with 80 additions and 1 deletions
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2
qemu/target/i386/fpu_helper.c
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@ -1170,7 +1170,7 @@ static void do_xsave_fpu(CPUX86State *env, target_ulong ptr, uintptr_t ra)
/* In 32-bit mode this is eip, sel, dp, sel.
In 64-bit mode this is rip, rdp.
But in either case we don't write actual data, just zeros. */
cpu_stq_data_ra(env, ptr + XO(legacy.fpip), 0, ra); /* eip+sel; rip */
cpu_stq_data_ra(env, ptr + XO(legacy.fpip), env->fpip, ra); /* eip+sel; rip */
cpu_stq_data_ra(env, ptr + XO(legacy.fpdp), 0, ra); /* edp+sel; rdp */
addr = ptr + XO(legacy.fpregs);

79
tests/unit/test_x86.c
View File

@ -1513,6 +1513,83 @@ static void test_x86_64_not_overwriting_tmp0_for_pc_update()
OK(uc_close(uc));
}
#define MEM_BASE 0x40000000
#define MEM_SIZE 1024*1024
#define MEM_STACK MEM_BASE + (MEM_SIZE / 2)
#define MEM_TEXT MEM_STACK + 4096
static void test_fxsave_fpip_x86(void) {
// note: fxsave was introduced in Pentium II
uint8_t code_x86[] = {
// help testing through NOP offset [disassembly in at&t syntax]
0x90, 0x90, 0x90, 0x90, // nop nop nop nop
// run a floating point instruction
0xdb, 0xc9, // fcmovne %st(1), %st
// fxsave needs 512 bytes of storage space
0x81, 0xec, 0x00, 0x02, 0x00, 0x00, // subl $512, %esp
// fxsave needs a 16-byte aligned address for storage
0x83, 0xe4, 0xf0, // andl $0xfffffff0, %esp
// store fxsave data on the stack
0x0f, 0xae, 0x04, 0x24, // fxsave (%esp)
// fxsave stores FPIP at an 8-byte offset, move FPIP to eax register
0x8b, 0x44, 0x24, 0x08 // movl 0x8(%esp), %eax
};
uc_err err;
uint32_t X86_NOP_OFFSET = 4;
uint32_t stack_top = (uint32_t) MEM_STACK;
uint32_t value;
uc_engine *uc;
// initialize emulator in X86-32bit mode
OK(uc_open(UC_ARCH_X86, UC_MODE_32, &uc));
// map 1MB of memory for this emulation
OK(uc_mem_map(uc, MEM_BASE, MEM_SIZE, UC_PROT_ALL));
OK(uc_mem_write(uc, MEM_TEXT, code_x86, sizeof(code_x86)));
OK(uc_reg_write(uc, UC_X86_REG_ESP, &stack_top));
OK(uc_emu_start(uc, MEM_TEXT, MEM_TEXT + sizeof(code_x86), 0, 0));
OK(uc_reg_read(uc, UC_X86_REG_EAX, &value));
TEST_CHECK(value == ((uint32_t) MEM_TEXT + X86_NOP_OFFSET));
OK(uc_mem_unmap(uc, MEM_BASE, MEM_SIZE));
OK(uc_close(uc));
}
static void test_fxsave_fpip_x64(void) {
uint8_t code_x64[] = {
// help testing through NOP offset [disassembly in at&t]
0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, // nops
// run a floating point instruction
0xdb, 0xc9, // fcmovne %st(1), %st
// fxsave64 needs 512 bytes of storage space
0x48, 0x81, 0xec, 0x00, 0x02, 0x00, 0x00, // subq $512, %rsp
// fxsave needs a 16-byte aligned address for storage
0x48, 0x83, 0xe4, 0xf0, // andq 0xfffffffffffffff0, %rsp
// store fxsave64 data on the stack
0x48, 0x0f, 0xae, 0x04, 0x24, // fxsave64 (%rsp)
// fxsave64 stores FPIP at an 8-byte offset, move FPIP to rax register
0x48, 0x8b, 0x44, 0x24, 0x08, // movq 0x8(%rsp), %rax
};
uc_err err;
uint64_t stack_top = (uint64_t) MEM_STACK;
uint64_t X64_NOP_OFFSET = 8;
uint64_t value;
uc_engine *uc;
// initialize emulator in X86-32bit mode
OK(uc_open(UC_ARCH_X86, UC_MODE_64, &uc));
// map 1MB of memory for this emulation
OK(uc_mem_map(uc, MEM_BASE, MEM_SIZE, UC_PROT_ALL));
OK(uc_mem_write(uc, MEM_TEXT, code_x64, sizeof(code_x64)));
OK(uc_reg_write(uc, UC_X86_REG_RSP, &stack_top));
OK(uc_emu_start(uc, MEM_TEXT, MEM_TEXT + sizeof(code_x64), 0, 0));
OK(uc_reg_read(uc, UC_X86_REG_RAX, &value));
TEST_CHECK(value == ((uint64_t) MEM_TEXT + X64_NOP_OFFSET));
OK(uc_mem_unmap(uc, MEM_BASE, MEM_SIZE));
OK(uc_close(uc));
}
TEST_LIST = {
{"test_x86_in", test_x86_in},
{"test_x86_out", test_x86_out},
@ -1562,4 +1639,6 @@ TEST_LIST = {
{"test_x86_0xff_lcall", test_x86_0xff_lcall},
{"test_x86_64_not_overwriting_tmp0_for_pc_update",
test_x86_64_not_overwriting_tmp0_for_pc_update},
{"test_fxsave_fpip_x86", test_fxsave_fpip_x86},
{"test_fxsave_fpip_x64", test_fxsave_fpip_x64},
{NULL, NULL}};