patch multiple UC_HOOK_MEM callbacks for unaligned access

[Michael-c0de]

The issue #1041 has not been fully resolved，fixed this bug to prevent unaligned accesses from triggering extra callbacks.

[wtdcode]

Do you have a test case for this?

[Michael-c0de]

Do you have a test case for this?

#include <unicorn/unicorn.h>

void hook_mem(uc_engine *uc, uc_mem_type type,
    uint64_t address, int size, int64_t value, void *user_data)
{
    printf("%s %p %d\n", (type == UC_MEM_WRITE) ? "write" : "read ", address, size);
}

int main(int argc, char **argv)
{
    const uint8_t code[] = {
        "\x48\x8b\x00"  //  mov         rax,qword ptr [rax]  
        "\x48\x89\x01"  //   mov         qword ptr [rcx],rax  
        "\xcc"
    };

    uc_engine *uc;
    uc_open(UC_ARCH_X86, UC_MODE_64, &uc);
    uc_mem_map(uc, 0, 0x10000, UC_PROT_ALL);
    uc_mem_write(uc, 0, code, sizeof(code) - 1);

    uc_hook hh;
    uc_hook_add(uc, &hh, UC_HOOK_MEM_READ | UC_HOOK_MEM_WRITE, hook_mem, NULL, 1, 0);

    const uint64_t addr = 0x1fff;
    uc_reg_write(uc, UC_X86_REG_RAX, &addr);
    uc_reg_write(uc, UC_X86_REG_RCX, &addr);
    uc_emu_start(uc, 0, sizeof(code) - 1, 0, 2);

    return 0;
}

before patch

read  0x1fff 8
read  0x1ff8 8
read  0x2000 8
write 0x1fff 8

after patch

read  0x1fff 8
write 0x1fff 8

[wtdcode]

Do you have a test case for this?

#include <unicorn/unicorn.h>

void hook_mem(uc_engine *uc, uc_mem_type type,
    uint64_t address, int size, int64_t value, void *user_data)
{
    printf("%s %p %d\n", (type == UC_MEM_WRITE) ? "write" : "read ", address, size);
}

int main(int argc, char **argv)
{
    const uint8_t code[] = {
        "\x48\x8b\x00"  //  mov         rax,qword ptr [rax]  
        "\x48\x89\x01"  //   mov         qword ptr [rcx],rax  
        "\xcc"
    };

    uc_engine *uc;
    uc_open(UC_ARCH_X86, UC_MODE_64, &uc);
    uc_mem_map(uc, 0, 0x10000, UC_PROT_ALL);
    uc_mem_write(uc, 0, code, sizeof(code) - 1);

    uc_hook hh;
    uc_hook_add(uc, &hh, UC_HOOK_MEM_READ | UC_HOOK_MEM_WRITE, hook_mem, NULL, 1, 0);

    const uint64_t addr = 0x1fff;
    uc_reg_write(uc, UC_X86_REG_RAX, &addr);
    uc_reg_write(uc, UC_X86_REG_RCX, &addr);
    uc_emu_start(uc, 0, sizeof(code) - 1, 0, 2);

    return 0;
}

before patch

read  0x1fff 8
read  0x1ff8 8
read  0x2000 8
write 0x1fff 8

after patch

read  0x1fff 8
write 0x1fff 8

Cool, could you add this to tests/unit/test_x86.c? This ensures that your use cases won't be broken in our futures releases.

[wtdcode]

No worry for CI. Github Action is buggy at this moment.