From: Ammar Faizi <ammarfaizi2@xxxxxxxxxxx>
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@xxxxxxxxxxx>
---
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
