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Fix pushing arguments to stack #5

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merged 2 commits into from
Oct 24, 2023
Merged

Fix pushing arguments to stack #5

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d2495ff
fix write stack arguments
5ec1cff Oct 23, 2023
b649cb4
ensure stack arguments are 16-bytes aligned
5ec1cff Oct 23, 2023
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44 changes: 25 additions & 19 deletions src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,14 @@ use libc::{pid_t, ptrace, PTRACE_ATTACH, PTRACE_CONT, PTRACE_DETACH};
use std::{mem, process::Child};
use thiserror::Error;

fn usize_arr_to_u8(data: &[usize]) -> Vec<u8> {
let mut arr: Vec<u8> = Vec::new();
for p in data {
arr.extend_from_slice(&p.to_le_bytes());
}
return arr;
}

#[derive(Debug, Error)]
pub enum TraceError {
#[error("Ptrace error: `{0}`")]
Expand Down Expand Up @@ -204,6 +212,7 @@ where
);

let cached_registers = current_registers.clone();
current_registers.set_stack_pointer(current_registers.stack_pointer() & !0xfusize);
for (i, param) in parameters[..std::cmp::min(parameters.len(), REGISTER_ARGUMENTS)]
.iter()
.enumerate()
Expand All @@ -219,12 +228,10 @@ where

// adjust stack pointer
current_registers.set_stack_pointer(
current_registers.stack_pointer() - (stack_arguments.len() * size_of::<usize>()),
current_registers.stack_pointer() - (((stack_arguments.len() + 1) & !1usize) * size_of::<usize>()),
);

self.write_memory(current_registers.stack_pointer(), unsafe {
std::mem::transmute(stack_arguments)
})?;
self.write_memory(current_registers.stack_pointer(), usize_arr_to_u8(stack_arguments).as_slice())?;
};

// set registers cached_registers
Expand Down Expand Up @@ -292,6 +299,7 @@ where
);

let cached_registers = current_registers.clone();
current_registers.set_stack_pointer(current_registers.stack_pointer() & !0xfusize);
for (i, param) in parameters[..std::cmp::min(parameters.len(), REGISTER_ARGUMENTS)]
.iter()
.enumerate()
Expand All @@ -307,12 +315,10 @@ where

// adjust stack pointer
current_registers.set_stack_pointer(
current_registers.stack_pointer() - (stack_arguments.len() * size_of::<usize>()),
current_registers.stack_pointer() - (((stack_arguments.len() + 3) & !3usize) * size_of::<usize>()),
);

self.write_memory(current_registers.stack_pointer(), unsafe {
std::mem::transmute(stack_arguments)
})?;
self.write_memory(current_registers.stack_pointer(), usize_arr_to_u8(stack_arguments).as_slice())?;
};

// set registers cached_registers
Expand Down Expand Up @@ -359,16 +365,17 @@ where

let cached_registers = current_registers.clone();
let param_count = parameters.len();
current_registers.set_stack_pointer(current_registers.stack_pointer() & !0xfusize);

tracing::trace!("Function parameters: {:?}", parameters);

// adjust stack pointer
current_registers.set_stack_pointer(
current_registers.stack_pointer() - (param_count * size_of::<usize>()),
);
self.write_memory(current_registers.stack_pointer(), unsafe {
std::mem::transmute(parameters)
})?;
if param_count > 0 {
// adjust stack pointer
current_registers.set_stack_pointer(
current_registers.stack_pointer() - (((param_count + 3) & !3usize) * size_of::<usize>()),
);
self.write_memory(current_registers.stack_pointer(), usize_arr_to_u8(parameters).as_slice())?;
}

// return address is bottom of stack!
current_registers.set_stack_pointer(current_registers.stack_pointer() - size_of::<usize>());
Expand Down Expand Up @@ -416,6 +423,7 @@ where

let cached_registers = current_registers.clone();
let param_count = parameters.len();
current_registers.set_stack_pointer(current_registers.stack_pointer() & !0xfusize);

// You gotta a better idea???????
if param_count > 0 {
Expand Down Expand Up @@ -443,11 +451,9 @@ where

// adjust stack pointer
current_registers.set_stack_pointer(
current_registers.stack_pointer() - (stack_arguments.len() * size_of::<usize>()),
current_registers.stack_pointer() - (((stack_arguments.len() + 1) & !1usize) * size_of::<usize>()),
);
self.write_memory(current_registers.stack_pointer(), unsafe {
std::mem::transmute(stack_arguments)
})?;
self.write_memory(current_registers.stack_pointer(), usize_arr_to_u8(stack_arguments).as_slice())?;
};

// return address is bottom of stack!
Expand Down
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