diff options
| author | Andrea Fioraldi <andreafioraldi@gmail.com> | 2019-09-12 16:57:17 +0200 |
|---|---|---|
| committer | Andrea Fioraldi <andreafioraldi@gmail.com> | 2019-09-12 16:57:17 +0200 |
| commit | 75d28813023c00144675eae7b75f4138ae9f317e (patch) | |
| tree | e4b1d695fab792be888fc2a821b4b9b670ce7122 /qemu_mode | |
| parent | 95b641198e512bdaf3f8c142d5f6d58495d527a8 (diff) | |
| download | afl++-75d28813023c00144675eae7b75f4138ae9f317e.tar.gz | |
ret addr patching
Diffstat (limited to 'qemu_mode')
| -rwxr-xr-x | qemu_mode/libcompcov/compcovtest | bin | 0 -> 8624 bytes | |||
| -rw-r--r-- | qemu_mode/patches/afl-qemu-common.h | 1 | ||||
| -rw-r--r-- | qemu_mode/patches/afl-qemu-cpu-inl.h | 9 | ||||
| -rw-r--r-- | qemu_mode/patches/afl-qemu-cpu-translate-inl.h | 39 |
4 files changed, 32 insertions, 17 deletions
diff --git a/qemu_mode/libcompcov/compcovtest b/qemu_mode/libcompcov/compcovtest new file mode 100755 index 00000000..0bb68d60 --- /dev/null +++ b/qemu_mode/libcompcov/compcovtest Binary files differdiff --git a/qemu_mode/patches/afl-qemu-common.h b/qemu_mode/patches/afl-qemu-common.h index f05dc05b..053585a7 100644 --- a/qemu_mode/patches/afl-qemu-common.h +++ b/qemu_mode/patches/afl-qemu-common.h @@ -57,6 +57,7 @@ extern abi_ulong afl_persistent_ret_addr; extern u8 afl_compcov_level; extern unsigned char afl_fork_child; extern unsigned char is_persistent; +extern target_long persistent_stack_offset; extern __thread abi_ulong afl_prev_loc; diff --git a/qemu_mode/patches/afl-qemu-cpu-inl.h b/qemu_mode/patches/afl-qemu-cpu-inl.h index 826167eb..2e685d8d 100644 --- a/qemu_mode/patches/afl-qemu-cpu-inl.h +++ b/qemu_mode/patches/afl-qemu-cpu-inl.h @@ -86,6 +86,7 @@ static int forkserver_installed = 0; unsigned char afl_fork_child; unsigned int afl_forksrv_pid; unsigned char is_persistent; +target_long persistent_stack_offset; /* Instrumentation ratio: */ @@ -200,9 +201,10 @@ static void afl_setup(void) { if (is_persistent) { afl_persistent_addr = strtoll(getenv("AFL_QEMU_PERSISTENT_ADDR"), NULL, 16); - if (getenv("AFL_QEMU_PERSISTENT_RET") == NULL) exit(1); - afl_persistent_ret_addr = - strtoll(getenv("AFL_QEMU_PERSISTENT_RET"), NULL, 16); + if (getenv("AFL_QEMU_PERSISTENT_RET")) + afl_persistent_ret_addr = + strtoll(getenv("AFL_QEMU_PERSISTENT_RET"), NULL, 16); + /* If AFL_QEMU_PERSISTENT_RET is not specified patch the return addr */ } @@ -345,6 +347,7 @@ void afl_persistent_loop() { cycle_cnt = afl_persistent_cnt; first_pass = 0; + persistent_stack_offset = TARGET_LONG_BITS / 8; return; diff --git a/qemu_mode/patches/afl-qemu-cpu-translate-inl.h b/qemu_mode/patches/afl-qemu-cpu-translate-inl.h index fe1b26b8..cd5c21aa 100644 --- a/qemu_mode/patches/afl-qemu-cpu-translate-inl.h +++ b/qemu_mode/patches/afl-qemu-cpu-translate-inl.h @@ -128,19 +128,30 @@ static void afl_gen_compcov(target_ulong cur_loc, TCGv_i64 arg1, TCGv_i64 arg2, } -#define AFL_QEMU_TARGET_i386_SNIPPET \ - if (is_persistent) { \ - \ - if (s->pc == afl_persistent_addr) { \ - \ - tcg_gen_afl_call0(&afl_persistent_loop); \ - \ - } else if (s->pc == afl_persistent_ret_addr) { \ - \ - gen_jmp_im(s, afl_persistent_addr); \ - gen_eob(s); \ - \ - } \ - \ +#define AFL_QEMU_TARGET_i386_SNIPPET \ + if (is_persistent) { \ + \ + if (s->pc == afl_persistent_addr) { \ + \ + if (afl_persistent_ret_addr == 0) { \ + \ + TCGv_ptr stack_off_ptr = tcg_const_ptr(&persistent_stack_offset); \ + TCGv stack_off = tcg_temp_new(); \ + tcg_gen_ld_tl(stack_off, stack_off_ptr, 0); \ + tcg_gen_sub_tl(cpu_regs[R_ESP], cpu_regs[R_ESP], stack_off); \ + tcg_temp_free(stack_off); \ + \ + } \ + TCGv_ptr paddr = tcg_const_ptr(afl_persistent_addr); \ + tcg_gen_st_tl(paddr, cpu_regs[R_ESP], 0); \ + tcg_gen_afl_call0(&afl_persistent_loop); \ + \ + } else if (afl_persistent_ret_addr && s->pc == afl_persistent_ret_addr) { \ + \ + gen_jmp_im(s, afl_persistent_addr); \ + gen_eob(s); \ + \ + } \ + \ } |