[PATCH v6 00/13] syscalls: Add a shared table for all archs

["André Almeida" <andrealmeid@igalia.com>]

While implementing a new syscall, we need to wire up it's number to the arch
table. Since syscall number 403, all architectures are on sync regarding the
number (except alpha), which make things a lot easier but more repetitive as
well. Have a look at commit b36d4b6aa88 ("arch: hookup listns() system call"),
with 15 lines of mostly:

  +470    common  listns                          sys_listns

There's already a "common" table shared with a bunch of archs at
`scripts/syscall.tbl`, but due to historical reasons some archs will never be
able to move to this table and share all the numbers.

The generic table starts from 403 (clock_gettime64), the first common syscall.

I've compile tested for arm32, arm64, s390, mips, sparc and alpha by comparing
the syscalls_*.h and unistd_*.h files generated before and after this patchset.
For most of cases the files are identical, for the few cases that they are not,
there's a note in the commit explaining why they are equivalent.

Thanks!
	André

Changes in v6:
- Rebased on top of 7.3-rc0: new syscall fchroot()
- Fix compliance with POSIX shells
- Add $(syscalltbl_common) to the prereq build files, so the build is triggered
if the common table changes
- v5: https://patch.msgid.link/20260812-tonyk-syscall_table-v5-0-3d383927c609@igalia.com

Changes in v5:
- Add archs lists to Cc
- alpha: Change custom alpha_syscall to __syscall
- mips: Use "common" for all ABI tables
- mips: Kept it as a single table for n32/n64
- Fix bug introduced by mixing --offset and --compat-offset
- v4: https://patch.msgid.link/20260812-tonyk-syscall_table-v4-0-748d0229ad40@igalia.com

Changes in v4:
- Replace cln3 with clone3 in the ABIs
- mips: Get rid of custom mips ABIs (o32, n32, n64) and use 32 and 64
- mips: Unify n32 and n64 tables
- Add alpha to the syscall party, along with it's adaptations
- Remove --no-compat option and define SYSCALL_WITH_COMPAT() macro for archs
that need it
- v3: https://patch.msgid.link/20260807-tonyk-syscall_table-v3-0-7c45a23c50b5@igalia.com

Changes in v3:
- Removed x86 for now, let's wait till x32 is dropped
- Added much more archs
- v2: https://patch.msgid.link/20260727-tonyk-syscall_table-v2-0-95d4f1ee471f@igalia.com

Changes in v2:
- Managed to move to the real first common syscall: 403 (clock_gettime64)
- Added -no-compat option to be used with x86_64
- v1: https://patch.msgid.link/20260724-tonyk-syscall_table-v1-0-9c53188423da@igalia.com

---
André Almeida (13):
      syscalls: Make --abis parsing more robust
      syscalls: Create unified partial table for all archs
      scripts/syscall.tbl: Use the common table
      arm: Use the common syscall table
      s390: Use the common syscall table
      sparc: Use the common syscall table
      mips: Remove duplicated syscallnr.sh
      mips: Get rid of custom mips ABIs for syscall tables
      mips: Use the common syscall table
      syscalls: Add an option for offsetting the common table
      alpha: Define entry point for set_mempolicy_home_node syscall
      alpha: Remove alpha_ prefix from custom syscall entries
      alpha: Use the common syscall table

 arch/alpha/kernel/entry.S                 |   8 +-
 arch/alpha/kernel/syscalls/Makefile       |  14 +-
 arch/alpha/kernel/syscalls/syscall.tbl    |  55 +-
 arch/alpha/kernel/systbls.S               |   1 +
 arch/arm/tools/Makefile                   |  14 +-
 arch/arm/tools/syscall.tbl                |  69 ---
 arch/arm64/tools/syscall_32.tbl           |  69 ---
 arch/mips/kernel/scall64-n32.S            |   1 +
 arch/mips/kernel/scall64-n64.S            |   2 +
 arch/mips/kernel/syscalls/Makefile        |  30 +-
 arch/mips/kernel/syscalls/syscall_n.tbl   | 464 +++++++++++++++++
 arch/mips/kernel/syscalls/syscall_n32.tbl | 413 ---------------
 arch/mips/kernel/syscalls/syscall_n64.tbl | 389 --------------
 arch/mips/kernel/syscalls/syscall_o32.tbl | 827 ++++++++++++++----------------
 arch/mips/kernel/syscalls/syscallnr.sh    |  26 -
 arch/s390/kernel/syscall.c                |   2 +
 arch/s390/kernel/syscalls/Makefile        |  12 +-
 arch/s390/kernel/syscalls/syscall.tbl     |  49 --
 arch/sparc/kernel/syscalls/Makefile       |  12 +-
 arch/sparc/kernel/syscalls/syscall.tbl    |  69 ---
 scripts/Makefile.asm-headers              |  15 +-
 scripts/syscall.tbl                       |  69 ---
 scripts/syscall_common.tbl                |  84 +++
 scripts/syscallhdr.sh                     |  83 ++-
 scripts/syscalltbl.sh                     |  50 +-
 25 files changed, 1111 insertions(+), 1716 deletions(-)
---
base-commit: 548e7bcd0c5460ddcbca9600cea603ebeebf4da7
change-id: 20260724-tonyk-syscall_table-928bbb1b26bb

Best regards,
--  
André Almeida <andrealmeid@igalia.com>