entry: Rework syscall skip logic
Status from this message: The following commit has been merged into the core/entry branch of tip:
Get series with b4
b4 am [email protected]Versions newest first
Patches in v1 Applied
| # | Subject and files | Size | Replies | Applied |
|---|---|---|---|---|
| 1/4 | entry: Rework syscall_audit_enter()include/ kernel/ | +13 | 2 replies | |
| 2/4 | entry: Rework trace_syscall_enter()include/ kernel/ | +6 | 2 replies | |
| 3/4 | entry: Make return type of syscall_trace_enter() boolinclude/ | +11 | 2 replies | |
| 4/4 | entry, treewide: Make syscall_enter_from_user_mode[_work]() indicate syscall executionDocumentation/ arch/ arch/ +5 more | +88 | 6 replies |
Reviews trailers per patch
All 4 patches have a Reviewed-by or Acked-by.
| Patch | Michal Suchánek | Jinjie Ruan | Radu Rendec |
|---|---|---|---|
| Series | T-b | ||
| 1/4 | R-b | R-b | |
| 2/4 | R-b | R-b | |
| 3/4 | R-b | R-b | |
| 4/4 | Originally-by | R-b |
Trailers given in replies are filled; those carried in the patches from earlier versions are outlined with dashes. Scroll the table sideways for all 3 reviewers.
Cover letter [patch 0/4] entry: Rework syscall skip logic
This are the reworked leftovers of the larger entry logic rework series, which can be found here:
https://lore.kernel.org/lkml/[email protected]
The undisputed part of the series has been merged into:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core/entry
After a fruitless discussion about the most resilent approach, I decided to give up wasting my time and reworked the series so it caters to the desire of powerpc and s390 to be special.
That results in almost identical behavior except for the case where tracing/probe/BPF sets the syscall number to -1 (or any other out of range value) and also sets the syscall return value to something different than -ENOSYS.
PowerPC and S390 will overwrite that value with -ENOSYS.
Loongarch, RISC-V and x86 will not overwrite it because those architectures preset the return value to -ENOSYS and skip out of range syscalls completely. Loongarch and RISC-V always did the out of range skip. X86 gained that in the already applied rework, which means that the final patch which splits the skip decision from the syscall number does not longer change x86 behavior for the above case.
Documentation is also updated and describes the two implementation variants and the subtle difference in the resulting behavior.
The series applies on top of:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core/entry
and is also available from git:
git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git entry/rework
Thanks,
tglx
--- Documentation/core-api/entry.rst | 45 +++++++++++++++++++++++------- arch/loongarch/kernel/syscall.c | 14 ++++----- arch/powerpc/kernel/syscall.c | 3 +- arch/riscv/kernel/traps.c | 11 +++---- arch/s390/kernel/syscall.c | 7 +++- arch/x86/entry/syscall_32.c | 25 ++++++++-------- arch/x86/entry/syscall_64.c | 12 ++++---- include/linux/entry-common.h | 58 +++++++++++++++++---------------------- kernel/entry/syscall-common.c | 19 ++++++++---- 9 files changed, 110 insertions(+), 84 deletions(-)