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Fixing stale code tlb after fetch-prot hook #2365

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Fixing stale code tlb after fetch-prot hook #2365

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16 changes: 16 additions & 0 deletions qemu/accel/tcg/cputlb.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1797,6 +1797,22 @@ load_helper(CPUArchState *env, target_ulong addr, TCGMemOpIdx oi,

if (handled) {
uc->invalid_error = UC_ERR_OK;
mr = uc->memory_mapping(uc, paddr);
if (mr == NULL || !(mr->perms & UC_PROT_EXEC)) {
uc->invalid_addr = paddr;
uc->invalid_error = mr == NULL ? UC_ERR_MAP : UC_ERR_FETCH_PROT;
if (uc->nested_level > 0 && !uc->cpu->stopped) {
cpu_exit(uc->cpu);
cpu_loop_exit_restore(uc->cpu, retaddr);
}
return 0;
}
tlb_fill(env_cpu(env), addr, size,
access_type, mmu_idx, retaddr);
index = tlb_index(env, mmu_idx, addr);
entry = tlb_entry(env, mmu_idx, addr);
tlb_addr = entry->addr_code;
tlb_addr &= ~TLB_INVALID_MASK;
tlb_hook_state_restore(env, &hook_state);
} else {
uc->invalid_addr = paddr;
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48 changes: 48 additions & 0 deletions tests/unit/test_x86.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1691,6 +1691,53 @@ static void test_x86_lazy_mapping(void)
OK(uc_close(uc));
}

static bool test_x86_fetch_prot_mem_protect_callback(uc_engine *uc,
uc_mem_type type,
uint64_t address, int size,
int64_t value,
void *user_data)
{
int *hook_count = (int *)user_data;
(*hook_count)++;

TEST_CHECK(type == UC_MEM_FETCH_PROT);
TEST_CHECK(address == 0x200000);
OK(uc_mem_protect(uc, 0x200000, 0x1000, UC_PROT_ALL));

return true;
}

static void test_x86_fetch_prot_mem_protect(void)
{
uc_engine *uc;
uc_hook hook;
int hook_count = 0;
uint64_t rip = 0;
uint64_t rsp = 0x300800;
char code[] = "\x48\xb8\x00\x00\x20\x00\x00\x00\x00\x00\xff\xe0";
char target[] = "\x90\x90\x90\xf4"; // nop; nop; nop; hlt

OK(uc_open(UC_ARCH_X86, UC_MODE_64, &uc));
OK(uc_mem_map(uc, 0x100000, 0x1000, UC_PROT_ALL));
OK(uc_mem_map(uc, 0x200000, 0x1000, UC_PROT_READ | UC_PROT_WRITE));
OK(uc_mem_map(uc, 0x300000, 0x1000, UC_PROT_ALL));
OK(uc_mem_write(uc, 0x100000, code, sizeof(code) - 1));
OK(uc_mem_write(uc, 0x200000, target, sizeof(target) - 1));
OK(uc_mem_protect(uc, 0x200000, 0x1000, UC_PROT_READ));
OK(uc_reg_write(uc, UC_X86_REG_RSP, &rsp));
OK(uc_hook_add(uc, &hook, UC_HOOK_MEM_FETCH_PROT,
test_x86_fetch_prot_mem_protect_callback, &hook_count, 1,
0));

OK(uc_emu_start(uc, 0x100000, 0, 0, 100));
OK(uc_reg_read(uc, UC_X86_REG_RIP, &rip));
TEST_CHECK(hook_count == 1);
TEST_CHECK(rip == 0x200004);

OK(uc_hook_del(uc, hook));
OK(uc_close(uc));
}

static void test_x86_16_incorrect_ip_cb(uc_engine *uc, uint64_t address,
uint32_t size, void *data)
{
Expand Down Expand Up @@ -2787,6 +2834,7 @@ TEST_LIST = {

#endif
{"test_x86_lazy_mapping", test_x86_lazy_mapping},
{"test_x86_fetch_prot_mem_protect", test_x86_fetch_prot_mem_protect},
{"test_x86_16_incorrect_ip", test_x86_16_incorrect_ip},
{"test_x86_mmu", test_x86_mmu},
{"test_x86_read_virtual", test_x86_read_virtual},
Expand Down
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