From: "Arnd Bergmann" <arnd@arndb.de>
To: "Michael Ellerman" <mpe@ellerman.id.au>,
"Rohan McLure" <rmclure@linux.ibm.com>,
linuxppc-dev@lists.ozlabs.org
Cc: Nicholas Piggin <npiggin@gmail.com>
Subject: Re: [PATCH v6 13/25] powerpc: Remove direct call to mmap2 syscall handlers
Date: Fri, 30 Sep 2022 16:09:54 +0200 [thread overview]
Message-ID: <dfeda168-c22b-4c4e-87d7-7b28e5fbd881@app.fastmail.com> (raw)
In-Reply-To: <87h70pov7x.fsf@mpe.ellerman.id.au>
On Fri, Sep 30, 2022, at 3:19 PM, Michael Ellerman wrote:
> "Arnd Bergmann" <arnd@arndb.de> writes:
>>
>> While sys_mmap_pgoff() was meant to replace the various sys_mmap2()
>> implementations, I think it was ultimately a mistake, and we later
>> converged on the sys_mmap2() calling conventions with 12 bits
>> offset for almost all 32-bit architectures.
>
> I only see 3 compat mmap2s:
>
> $ gg "COMPAT_SYSCALL.*mmap2"
> arch/arm64/kernel/sys32.c:COMPAT_SYSCALL_DEFINE6(aarch32_mmap2,
> unsigned long, addr, unsigned long, len,
> arch/powerpc/kernel/syscalls.c:COMPAT_SYSCALL_DEFINE6(mmap2, unsigned
> long, addr, size_t, len,
> arch/s390/kernel/compat_linux.c:COMPAT_SYSCALL_DEFINE1(s390_mmap2,
> struct mmap_arg_struct_emu31 __user *, arg)
They are all inconsistently named, and some are shared with the 64-bit
implementation on architectures that provide mmap2 for both 32-bit
and 64-bit mode, rather than only for 32-bit.
arch/mips/kernel/syscall.c:SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
arch/sparc/kernel/sys32.S: .globl sys32_mmap2
arch/parisc/kernel/sys_parisc.c:asmlinkage unsigned long sys_mmap2(unsigned long addr, unsigned long len,
> s390 is weird.
Right, they used to be limited to 5 register arguments
> The arm64 one and ours are similar, but we have the additional call to
> arch_validate_prot(prot, addr). arm64 does implement arch_validate_prot().
>
> Similar with mmap2, we call arch_validate_prot() but no one else does
> (why not?).
This looks like it was added in ef3d3246a0d0 ("powerpc/mm: Add Strong
Access Ordering support"), which is powerpc specific. It looks like
this should correspond to a custom arch_calc_vm_prot_bits()
implementation, which exists on arm64, powerpc, sparc and x86.
I suppose it should be there for those four.
Arnd
next prev parent reply other threads:[~2022-09-30 14:11 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-21 6:55 [PATCH v6 00/25] powerpc: Syscall wrapper and register clearing Rohan McLure
2022-09-21 6:55 ` [PATCH v6 01/25] powerpc: Remove asmlinkage from syscall handler definitions Rohan McLure
2022-09-21 6:55 ` [PATCH v6 02/25] powerpc: Save caller r3 prior to system_call_exception Rohan McLure
2022-09-21 6:55 ` [PATCH v6 03/25] powerpc: Add ZEROIZE_GPRS macros for register clears Rohan McLure
2022-09-21 6:55 ` [PATCH v6 04/25] powerpc/64s: Use {ZEROIZE,SAVE,REST}_GPRS macros in sc, scv 0 handlers Rohan McLure
2022-09-21 6:55 ` [PATCH v6 05/25] powerpc/32: Clarify interrupt restores with REST_GPR macro in entry_32.S Rohan McLure
2022-09-21 6:55 ` [PATCH v6 06/25] powerpc/64e: Clarify register saves and clears with {SAVE,ZEROIZE}_GPRS Rohan McLure
2022-09-21 6:55 ` [PATCH v6 07/25] powerpc/64s: Fix comment on interrupt handler prologue Rohan McLure
2022-09-21 6:55 ` [PATCH v6 08/25] powerpc: Fix fallocate and fadvise64_64 compat parameter combination Rohan McLure
2022-09-21 6:55 ` [PATCH v6 09/25] asm-generic: compat: Support BE for long long args in 32-bit ABIs Rohan McLure
2022-10-31 13:23 ` [PATCH] asm-generic: compat: fix compat_arg_u64 and compat_arg_u64_dual Andreas Schwab
2022-11-01 12:25 ` Michael Ellerman
2022-11-03 8:20 ` Christophe Leroy
2022-11-03 8:48 ` Arnd Bergmann
2022-09-21 6:55 ` [PATCH v6 10/25] powerpc: Use generic fallocate compatibility syscall Rohan McLure
2022-09-21 6:55 ` [PATCH v6 11/25] powerpc/32: Remove powerpc select specialisation Rohan McLure
2022-09-21 6:55 ` [PATCH v6 12/25] powerpc: Remove direct call to personality syscall handler Rohan McLure
2022-09-21 6:55 ` [PATCH v6 13/25] powerpc: Remove direct call to mmap2 syscall handlers Rohan McLure
2022-09-28 12:15 ` Michael Ellerman
2022-09-28 13:00 ` Arnd Bergmann
2022-09-30 13:19 ` Michael Ellerman
2022-09-30 14:09 ` Arnd Bergmann [this message]
2022-09-21 6:55 ` [PATCH v6 14/25] powerpc: Provide do_ppc64_personality helper Rohan McLure
2022-09-21 6:55 ` [PATCH v6 15/25] powerpc: Adopt SYSCALL_DEFINE for arch-specific syscall handlers Rohan McLure
2022-09-21 6:55 ` [PATCH v6 16/25] powerpc: Include all arch-specific syscall prototypes Rohan McLure
2022-09-21 6:55 ` [PATCH v6 17/25] powerpc: Enable compile-time check for syscall handlers Rohan McLure
2022-09-21 6:55 ` [PATCH v6 18/25] powerpc: Use common syscall handler type Rohan McLure
2022-09-21 6:55 ` [PATCH v6 19/25] powerpc: Remove high-order word clearing on compat syscall entry Rohan McLure
2022-09-23 7:40 ` Nicholas Piggin
2022-09-28 11:56 ` Michael Ellerman
2022-09-21 6:56 ` [PATCH v6 20/25] powerpc: Change system_call_exception calling convention Rohan McLure
2022-09-23 7:43 ` Nicholas Piggin
2022-09-21 6:56 ` [PATCH v6 21/25] powerpc: Provide syscall wrapper Rohan McLure
2022-09-23 7:50 ` Nicholas Piggin
2022-10-30 15:34 ` Andreas Schwab
2022-10-30 15:50 ` Andreas Schwab
2022-10-30 19:43 ` Arnd Bergmann
2022-10-30 20:05 ` Andreas Schwab
2022-10-31 3:09 ` Michael Ellerman
2022-10-31 14:47 ` [PATCH] powerpc/32: fix syscall wrappers with 64-bit arguments Andreas Schwab
2022-10-31 19:37 ` Arnd Bergmann
2022-11-01 12:25 ` Michael Ellerman
2022-09-21 6:56 ` [PATCH v6 22/25] powerpc/64s: Clear user GPRs in syscall interrupt entry Rohan McLure
2022-09-23 8:02 ` Nicholas Piggin
2022-10-31 23:22 ` Rohan McLure
2022-09-21 6:56 ` [PATCH v6 23/25] powerpc/64: Add INTERRUPT_SANITIZE_REGISTERS Kconfig Rohan McLure
2022-09-21 6:56 ` [PATCH v6 24/25] powerpc/64s: Clear gprs on interrupt routine entry in Book3S Rohan McLure
2022-09-21 6:56 ` [PATCH v6 25/25] powerpc/64e: Clear gprs on interrupt routine entry on Book3E Rohan McLure
2022-10-04 13:24 ` [PATCH v6 00/25] powerpc: Syscall wrapper and register clearing Michael Ellerman
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