rust-embedded-community/tinyrlibc

Tiny C library written in Rust

tinyrlibc's Issues

Ship 0.3.0

I think we should do a 0.3.0 release, including the latest functions needed for nrfxlib.

problems linking against tinyrlibc

Hi, I'm currently attempting to use tinyrlibc in a project with the nrf9160. I've managed to build the library both standalone and as a project dependency, however, I can't seem to get the project to link using the tinyrlibc binary outputs.

rust-lld: error: undefined symbol: strncpy
          >>> referenced by tls.c.obj:(tls_attach) in archive /Users/kpw/workspace/hardware/embassy/examples/nrf9160/target/thumbv8m.main-none-eabihf/release/deps/libnrfxlib_sys-fe2aec5671652a3b.rlib
          
          rust-lld: error: undefined symbol: vsnprintf
          >>> referenced by nrf_modem_at.c.obj:(at_vsprintf) in archive /Users/kpw/workspace/hardware/embassy/examples/nrf9160/target/thumbv8m.main-none-eabihf/release/deps/libnrfxlib_sys-fe2aec5671652a3b.rlib
          >>> referenced by nrf_modem_at.c.obj:(at_vsprintf) in archive /Users/kpw/workspace/hardware/embassy/examples/nrf9160/target/thumbv8m.main-none-eabihf/release/deps/libnrfxlib_sys-fe2aec5671652a3b.rlib
          

When tinyrlibc it generates two entries in the /deps directory, one for the .a file generated by the c compiler, and another with the .rlib file that contains the rust and c code together.

By default the rustc linker appears to attempt to link against the c library, e.g."-L" "/Users/kpw/workspace/hardware/embassy/examples/nrf9160/target/thumbv8m.main-none-eabihf/release/build/tinyrlibc-a7e8ade98cfa3691/out"

I added a rustc -L arg to the .cargo/config.toml to manually link against the libtinyrlibc.rlibfile, however the progam still exits with the same missing symbol errors.

I'm curious if there are any examples of projects successfully using the library that demonstrate how to force the linker to incorporate these symbols?

As an fyi, here's the output of nm libtinyrlibc.rlib:

lib.rmeta:
/Users/kpw/workspace/hardware/embassy/examples/nrf9160/target/thumbv8m.main-none-eabihf/release/deps/libtinyrlibc-264159df859b252b.rlib:lib.rmeta: no symbols

tinyrlibc-264159df859b252b.tinyrlibc.406389e212438c16-cgu.0.rcgu.o:
00000000 r .Lanon.a7061450a32074659723700ab2f6815d.1
00000000 r .Lanon.a7061450a32074659723700ab2f6815d.2
         U _ZN4core5slice5index24slice_end_index_len_fail17hfd7d21569e4c2694E
         U _ZN4core9panicking5panic17h4cd43b1dff72db0cE
         U __aeabi_memclr
         U __aeabi_uldivmod
00000000 T abs
00000000 T atoi
00000000 T itoa
00000000 r str.1
00000000 T strchr
00000000 T strcmp
00000000 T strcpy
00000000 T strlen
00000000 T strncmp
00000000 T strncpy
00000000 T strstr
00000000 T strtol
00000000 T strtoul
00000000 T utoa

snprintf.o:
         U itoa
00000000 T snprintf
         U strtoul
         U utoa
00000000 T vsnprintf

Set ERRNO in strtol

On success, the function returns the converted integral number as a long int value.
If no valid conversion could be performed, a zero value is returned (0L).
If the value read is out of the range of representable values by a long int, the function returns LONG_MAX or LONG_MIN (defined in [<climits>](https://cplusplus.com/climits)), and [errno](https://cplusplus.com/errno) is set to ERANGE.

Errno should be set to ERANGE when value is out of range. Reimplementing something similar to errno in Newlib might be possible.

stack-buffer-overflow in strcpy::test::two

This test appears to intentionally corrupt memory:

	#[test]
	fn two() {
		let src = b"hi\0";
		let mut dest = [0u8; 2]; // no space for null terminator
		let result = unsafe { strcpy(dest.as_mut_ptr(), src.as_ptr()) };
		assert_eq!(unsafe { core::slice::from_raw_parts(result, 2) }, b"hi");
	}

https://asan.saethlin.dev/ub?crate=tinyrlibc&version=0.3.0

test strcpy::test::two ... =================================================================
==12736==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7ffb5f9f7eb2 at pc 0x559635b472fc bp 0x7ffba02f4830 sp 0x7ffba02f4828
WRITE of size 1 at 0x7ffb5f9f7eb2 thread T29
    #0 0x559635b472fb in strcpy /build/src/strcpy.rs:13:3
    #1 0x559635b4b057 in tinyrlibc::strcpy::test::two::h743566c6ea54f540 /build/src/strcpy.rs:42:25
    #2 0x559635b4af02 in tinyrlibc::strcpy::test::two::_$u7b$$u7b$closure$u7d$$u7d$::hd19b72cfcca7882c /build/src/strcpy.rs:39:10

Address 0x7ffb5f9f7eb2 is located in stack of thread T29 at offset 178 in frame
    #0 0x559635b4af2f in tinyrlibc::strcpy::test::two::h743566c6ea54f540 /build/src/strcpy.rs:39

  This frame has 4 object(s):
    [32, 80) '_17' (line 43)
    [112, 128) '_11' (line 43)
    [144, 160) '_9' (line 43)
    [176, 178) 'dest' (line 41) <== Memory access at offset 178 overflows this variable

SUMMARY: AddressSanitizer: stack-buffer-overflow /build/src/strcpy.rs:13:3 in strcpy
Shadow bytes around the buggy address:
  0x7ffb5f9f7c00: f1 f1 f1 f1 00 00 00 f2 f2 f2 f2 f2 00 00 00 f2
  0x7ffb5f9f7c80: f2 f2 f2 f2 00 00 00 f3 f3 f3 f3 f3 00 00 00 00
  0x7ffb5f9f7d00: f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5
  0x7ffb5f9f7d80: f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5 f5
  0x7ffb5f9f7e00: f1 f1 f1 f1 f8 f8 f8 f8 f8 f8 f2 f2 f2 f2 f8 f8
=>0x7ffb5f9f7e80: f2 f2 f8 f8 f2 f2[02]f3 00 00 00 00 00 00 00 00
  0x7ffb5f9f7f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x7ffb5f9f7f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x7ffb5f9f8000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x7ffb5f9f8080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  0x7ffb5f9f8100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
  Addressable:           00
  Partially addressable: 01 02 03 04 05 06 07 
  Heap left redzone:       fa
  Freed heap region:       fd
  Stack left redzone:      f1
  Stack mid redzone:       f2
  Stack right redzone:     f3
  Stack after return:      f5
  Stack use after scope:   f8
  Global redzone:          f9
  Global init order:       f6
  Poisoned by user:        f7
  Container overflow:      fc
  Array cookie:            ac
  Intra object redzone:    bb
  ASan internal:           fe
  Left alloca redzone:     ca
  Right alloca redzone:    cb
==12736==ABORTING

Fix: Don't write tests that intentionally trigger undefined behavior.

Scope of future function implementations

Hi, I am working on binding against a C library compiled with Newlib headers. This requires implementations of some functions that:

• requires extern crate alloc such as malloc and free
• are not part of libc, but part of the Newlib header such as __errno(), __assert_func()
• are just stubs for non-existent functions such as fopen, printf
• part of math.h (implementation of those are easy, just re-export the libm functions)

What is the scope of future function implementation in tinyrlibc?

Add CI

unable to build

When I try to build anything containing this library, I get the following error:

The following warnings were emitted during compilation:

warning: ./src/snprintf.c:18:10: fatal error: string.h: No such file or directory
warning:    18 | #include <string.h>
warning:       |          ^~~~~~~~~~
warning: compilation terminated.

error: failed to run custom build command for `tinyrlibc v0.2.1`

Caused by:
  process didn't exit successfully: `/home/stuart/nrf9160-dk-2/target/debug/build/tinyrlibc-8a872cb1cf75bcd4/build-script-build` (exit status: 1)
  --- stdout
  TARGET = Some("thumbv8m.main-none-eabihf")
  OPT_LEVEL = Some("0")
  HOST = Some("x86_64-unknown-linux-gnu")
  CC_thumbv8m.main-none-eabihf = None
  CC_thumbv8m.main_none_eabihf = None
  TARGET_CC = None
  CC = None
  CROSS_COMPILE = None
  CFLAGS_thumbv8m.main-none-eabihf = None
  CFLAGS_thumbv8m.main_none_eabihf = None
  TARGET_CFLAGS = None
  CFLAGS = None
  CRATE_CC_NO_DEFAULTS = None
  DEBUG = Some("true")
  CARGO_CFG_TARGET_FEATURE = Some("mclass,thumb-mode,v5te,v6,v6k,v6t2,v7")
  running: "arm-none-eabi-gcc" "-O0" "-ffunction-sections" "-fdata-sections" "-g" "-fno-omit-frame-pointer" "-mthumb" "-mfloat-abi=hard" "-march=armv8-m.main" "-mfpu=fpv5-sp-d16" "-Wall" "-Wextra" "-o" "/home/stuart/nrf9160-dk-2/target/thumbv8m.main-none-eabihf/debug/build/tinyrlibc-1af852193f2a9337/out/./src/snprintf.o" "-c" "./src/snprintf.c"
  cargo:warning=./src/snprintf.c:18:10: fatal error: string.h: No such file or directory
  cargo:warning=   18 | #include <string.h>
  cargo:warning=      |          ^~~~~~~~~~
  cargo:warning=compilation terminated.
  exit status: 1

  --- stderr


  error occurred: Command "arm-none-eabi-gcc" "-O0" "-ffunction-sections" "-fdata-sections" "-g" "-fno-omit-frame-pointer" "-mthumb" "-mfloat-abi=hard" "-march=armv8-m.main" "-mfpu=fpv5-sp-d16" "-Wall" "-Wextra" "-o" "/home/stuart/nrf9160-dk-2/target/thumbv8m.main-none-eabihf/debug/build/tinyrlibc-1af852193f2a9337/out/./src/snprintf.o" "-c" "./src/snprintf.c" with args "arm-none-eabi-gcc" did not execute successfully (status code exit status: 1).

this includes nrf9160-dk examples. I believe I have all of the listed dependencies correctly installed, but I suspect the issue lies with my gcc configuration. Any assistance here would be appreciated.

OS: Manjaro