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From: "H. Peter Anvin" <hpa@zytor.com>
To: Ingo Molnar <mingo@redhat.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Andy Lutomirski <luto@kernel.org>, Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: [RFC PATCH 0/6] x86/entry: cleanups and consistent syscall number handling
Date: Mon, 10 May 2021 10:45:03 -0700	[thread overview]
Message-ID: <20210510174509.3039991-1-hpa@zytor.com> (raw)

From: "H. Peter Anvin (Intel)" <hpa@zytor.com>

This patchset:

1. Cleans up some duplications between <entry/calling.h> and <asm/ptrace-abi.h>.

2. Swaps the arguments to do_syscall_64() for consistency *and* speed.

3. Adds the maximum number of flags to MSR_SYSCALL_MASK; the previous
   is more of a minimum. The more flags that are masked, the less the
   likelihood of a control leak into the kernel.

4. Consistently treat the system call number as a signed int. This is
   what syscall_get_nr() already does, and therefore what all
   architecture-independent code (e.g. seccomp) already expects.

5. Call sys_ni_syscall() for system calls which are out of range but
   still positive (negative system calls are used by ptrace and
   seccomp as a "skip system call" marker) just as for system call
   numbers that correspond to holes in the table.

6. In <entry/calling.h>, factor the PUSH_AND_CLEAR_REGS macro into
   separate PUSH_REGS and CLEAR_REGS macros which can be used
   separately if desired. This will be used by the FRED entry code at
   a later date.

--- 
 arch/x86/entry/calling.h       | 45 ++++++--------------------
 arch/x86/entry/common.c        | 71 ++++++++++++++++++++++++++++--------------
 arch/x86/entry/entry_64.S      |  4 +--
 arch/x86/include/asm/syscall.h | 13 ++++----
 arch/x86/kernel/cpu/common.c   | 12 +++++--
 arch/x86/kernel/head_64.S      |  6 ++--
 6 files changed, 77 insertions(+), 74 deletions(-)

             reply	other threads:[~2021-05-10 17:46 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-10 17:45 H. Peter Anvin [this message]
2021-05-10 17:45 ` [RFC PATCH 1/6] x86/entry: unify definitions from calling.h and ptrace-abi.h H. Peter Anvin
2021-05-10 17:45 ` [RFC PATCH 2/6] x86/entry: reverse arguments to do_syscall_64() H. Peter Anvin
2021-05-10 17:45 ` [RFC PATCH 3/6] x86/syscall: unconditionally prototype {ia32,x32}_sys_call_table[] H. Peter Anvin
2021-05-10 17:45 ` [RFC PATCH 4/6] x86/syscall: maximize MSR_SYSCALL_MASK H. Peter Anvin
2021-05-10 17:45 ` [RFC PATCH 5/6] x86/entry: use int for syscall number; handle all invalid syscall nrs H. Peter Anvin
2021-05-13  7:39   ` [x86/entry] 55b7c6747c: kernel-selftests.x86.syscall_numbering_64.fail kernel test robot
2021-05-10 17:45 ` [RFC PATCH 6/6] x86/entry: split PUSH_AND_CLEAR_REGS into two submacros H. Peter Anvin

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