lkml.org 
[lkml]   [2022]   [Dec]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Subject[RFC PATCH v1 0/8] nolibc signal handling support
Date
From: Ammar Faizi <ammarfaizi2@gnuweeb.org>

Hi,

This series adds signal handling support to the nolibc subsystem.

1) Initial implementation of nolibc sigaction(2) function.

Currently, this implementation is only available on the x86-64 arch.

sigaction() needs an architecture-dependent "signal trampoline"
function that invokes the __rt_sigreturn syscall to resume the process
after a signal gets handled.

On Linux x86-64, the "signal trampoline" function has to be written in
inline Assembly to prevent the compiler from controlling the %rsp
(e.g., with -fno-omit-frame-pointer, every function has a pushq
%rbp that makes the %rsp no longer point to struct rt_sigframe).

The "signal trampoline" function is called __arch_restore_rt in this
implementation.

2) signal(2) function.

signal() function is the simpler version of sigaction(). Unlike
sigaction(), which fully controls the struct sigaction, the caller
only cares about the sa_handler when calling the signal() function.

signal() internally calls sigaction(). This implementation is
currently only available on the x86-64 arch. When the sigaction()
function support is expanded to other architectures, this function
will automatically support those architectures. It's basically just
a sigaction() wrapper.

3) Extra nolibc updates.

Apart from the signal handling support. This series also contains
nolibc updates, they are:

- getpagesize() support.
- CFLAGS update.
- fork(2) selftest.
- sigaction(2) selftest.
- signal(2) selftest.
- getpagesize(2) selftest.

There 8 patches in this series. It has been tested on Linux x86-64 arch
and all tests OK.

$ sudo ./nolibc-test
Running test 'syscall'
...
...
66 wait_child = -1 ECHILD [OK]
67 waitpid_min = -1 ESRCH [OK]
68 waitpid_child = -1 ECHILD [OK]
69 write_badf = -1 EBADF [OK]
70 write_zero = 0 [OK]
Errors during this test: 0


Running test 'stdlib'
...
...
14 memcmp_60_20 = 64 [OK]
15 memcmp_20_e0 = -192 [OK]
16 memcmp_e0_20 = 192 [OK]
17 memcmp_80_e0 = -96 [OK]
18 memcmp_e0_80 = 96 [OK]
Errors during this test: 0

Total number of errors: 0
Exiting with status 0

$ make run -j8
Kernel: arch/x86/boot/bzImage is ready (#3)
...
82 test(s) passed.

Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
---

It's also available in the Git repository.

The following changes since commit caf5c36025ec9395c8d7c78957b016a284812d23:

srcu: Update comment after the index flip (2022-12-21 09:01:53 -0800)

are available in the Git repository at:

https://github.com/ammarfaizi2/linux-block testing/rfc.v1.2022-12-22.nolibc

for you to fetch changes up to ac79aca684125907bfbefadfd6c6be0ccdfe8b33:

selftests/nolibc: Add `getpagesize(2)` selftest (2022-12-22 09:57:31 +0700)

----------------------------------------------------------------
Ammar Faizi (8):
nolibc/sys: Implement `sigaction(2)` function
nolibc/sys: Implement `signal(2)` function
nolibc/sys: Implement `getpagesize(2)` function
selftests/nolibc: Add `-Wall` and `-Wno-unsed-function` to the CFLAGS
selftests/nolibc: Add `fork(2)` selftest
selftests/nolibc: Add `sigaction(2)` selftest
selftests/nolibc: Add `signal(2)` selftest
selftests/nolibc: Add `getpagesize(2)` selftest

tools/include/nolibc/arch-x86_64.h | 12 +
tools/include/nolibc/sys.h | 224 +++++++++++++++++++
tools/testing/selftests/nolibc/Makefile | 2 +-
tools/testing/selftests/nolibc/nolibc-test.c | 219 +++++++++++++++++-
4 files changed, 454 insertions(+), 3 deletions(-)


base-commit: caf5c36025ec9395c8d7c78957b016a284812d23
--
Ammar Faizi

\
 
 \ /
  Last update: 2023-03-26 23:17    [W:0.072 / U:2.256 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site