From 81da1bb1a3eb70e6c4c47f14b49ab419d501d277 Mon Sep 17 00:00:00 2001
From: oddcoder <ahmedsoliman@oddcoder.com>
Date: Sat, 13 Jun 2020 19:50:08 +0200
Subject: [PATCH] Fix the avoid accessing errno issue from ld_so for real this
time
This patch implements access function for both redox and linux and makes
sure that neither access errno variable
---
src/ld_so/access.rs | 53 +++++++++++++++++++++++++++++++++++++++++++++
src/ld_so/linker.rs | 3 +--
src/ld_so/mod.rs | 10 +++------
3 files changed, 57 insertions(+), 9 deletions(-)
create mode 100644 src/ld_so/access.rs
diff --git a/src/ld_so/access.rs b/src/ld_so/access.rs
new file mode 100644
index 000000000..624edff86
--- /dev/null
+++ b/src/ld_so/access.rs
@@ -0,0 +1,53 @@
+// Wrapper over the access syscall that doesn't touch errno variable,
+// Do not use outside of ld_so
+
+use crate::{c_str::CStr, platform::types::*};
+
+#[cfg(target_os = "redox")]
+use crate::header::unistd::{F_OK, R_OK, W_OK, X_OK};
+
+#[cfg(target_os = "linux")]
+pub unsafe fn access(path: *const c_char, mode: c_int) -> c_int {
+ let path = CStr::from_ptr(path);
+ syscall!(ACCESS, (path).as_ptr(), mode) as c_int
+}
+
+// Wrapper over the systemcall, Do not use outside of ld_so
+#[cfg(target_os = "redox")]
+pub unsafe fn access(path: *const c_char, mode: c_int) -> c_int {
+ let path = CStr::from_ptr(path).to_bytes();
+ let fd = match syscall::open(path, syscall::O_CLOEXEC) {
+ Ok(fd) => fd,
+ _ => return -1,
+ };
+ if mode == F_OK {
+ return 0;
+ }
+ let mut stat = syscall::Stat::default();
+ if syscall::fstat(fd, &mut stat).is_err() {
+ return -1;
+ }
+ let uid = match syscall::getuid() {
+ Ok(uid) => uid,
+ Err(_) => return -1,
+ };
+ let gid = match syscall::getgid() {
+ Ok(gid) => gid,
+ Err(_) => return -1,
+ };
+
+ let perms = if stat.st_uid as usize == uid {
+ stat.st_mode >> (3 * 2 & 0o7)
+ } else if stat.st_gid as usize == gid {
+ stat.st_mode >> (3 * 1 & 0o7)
+ } else {
+ stat.st_mode & 0o7
+ };
+ if (mode & R_OK == R_OK && perms & 0o4 != 0o4)
+ || (mode & W_OK == W_OK && perms & 0o2 != 0o2)
+ || (mode & X_OK == X_OK && perms & 0o1 != 0o1)
+ {
+ return -1;
+ }
+ 0
+}
diff --git a/src/ld_so/linker.rs b/src/ld_so/linker.rs
index 149f26543..ff6d89669 100644
--- a/src/ld_so/linker.rs
+++ b/src/ld_so/linker.rs
@@ -26,12 +26,11 @@ use crate::{
};
use super::{
- access,
+ access::access,
debug::{RTLDDebug, RTLDState, _dl_debug_state, _r_debug},
tcb::{Master, Tcb},
PAGE_SIZE,
};
-
#[cfg(target_os = "redox")]
const PATH_SEP: char = ';';
diff --git a/src/ld_so/mod.rs b/src/ld_so/mod.rs
index b39a5e7e2..baa253e6e 100644
--- a/src/ld_so/mod.rs
+++ b/src/ld_so/mod.rs
@@ -1,13 +1,15 @@
use goblin::elf::program_header::{self, program_header32, program_header64, ProgramHeader};
use self::tcb::{Master, Tcb};
-use crate::{c_str::CStr, platform::types::*, start::Stack};
+use crate::start::Stack;
pub const PAGE_SIZE: usize = 4096;
+mod access;
pub mod debug;
pub mod linker;
pub mod start;
pub mod tcb;
+
pub fn static_init(sp: &'static Stack) {
let mut phdr_opt = None;
let mut phent_opt = None;
@@ -79,12 +81,6 @@ pub fn static_init(sp: &'static Stack) {
}
}
-// Wrapper over the systemcall, Do not use outside of ld_so
-pub unsafe fn access(path: *const c_char, mode: c_int) -> c_int {
- let path = CStr::from_ptr(path);
- syscall!(ACCESS, (path).as_ptr(), mode) as c_int
-}
-
#[cfg(target_os = "linux")]
pub unsafe fn init(sp: &'static Stack) {
let mut tp = 0usize;
--
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