[PATCH v4 06/20] powerpc: Remove direct call to mmap2 syscall handlers

[Rohan McLure]

> On 12 Sep 2022, at 7:47 pm, Nicholas Piggin <npiggin at gmail.com> wrote:
> 
> On Wed Aug 24, 2022 at 12:05 PM AEST, Rohan McLure wrote:
>> Syscall handlers should not be invoked internally by their symbol names,
>> as these symbols defined by the architecture-defined SYSCALL_DEFINE
>> macro. Move the compatibility syscall definition for mmap2 to
>> syscalls.c, so that all mmap implementations can share an inline helper
>> function, as is done with the personality handlers.
>> 
>> Signed-off-by: Rohan McLure <rmclure at linux.ibm.com>
> 
> Is there any point to keping sys_ppc32.c at all? Might as well move them
> all to syscall.c IMO.

Currently serves as a fairly arbitrary distinginction between compat calls
and others, noting that a compat variant of personality is in syscalls.c.
May as well get rid of it.

> Reviewed-by: Nicholas Piggin <npiggin at gmail.com>
> 
>> ---
>> V1 -> V2: Move mmap2 compat implementation to asm/kernel/syscalls.c.
>> V3 -> V4: Move to be applied before syscall wrapper introduced.
>> ---
>> arch/powerpc/kernel/sys_ppc32.c |  9 ---------
>> arch/powerpc/kernel/syscalls.c  | 11 +++++++++++
>> 2 files changed, 11 insertions(+), 9 deletions(-)
>> 
>> diff --git a/arch/powerpc/kernel/sys_ppc32.c b/arch/powerpc/kernel/sys_ppc32.c
>> index f4edcc9489fb..bc6491ed6454 100644
>> --- a/arch/powerpc/kernel/sys_ppc32.c
>> +++ b/arch/powerpc/kernel/sys_ppc32.c
>> @@ -25,7 +25,6 @@
>> #include <linux/poll.h>
>> #include <linux/personality.h>
>> #include <linux/stat.h>
>> -#include <linux/mman.h>
>> #include <linux/in.h>
>> #include <linux/syscalls.h>
>> #include <linux/unistd.h>
>> @@ -48,14 +47,6 @@
>> #include <asm/syscalls.h>
>> #include <asm/switch_to.h>
>> 
>> -unsigned long compat_sys_mmap2(unsigned long addr, size_t len,
>> -			  unsigned long prot, unsigned long flags,
>> -			  unsigned long fd, unsigned long pgoff)
>> -{
>> -	/* This should remain 12 even if PAGE_SIZE changes */
>> -	return sys_mmap(addr, len, prot, flags, fd, pgoff << 12);
>> -}
>> -
>> /* 
>>  * long long munging:
>>  * The 32 bit ABI passes long longs in an odd even register pair.
>> diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c
>> index b8461128c8f7..32fadf3c2cd3 100644
>> --- a/arch/powerpc/kernel/syscalls.c
>> +++ b/arch/powerpc/kernel/syscalls.c
>> @@ -56,6 +56,17 @@ SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len,
>> 	return do_mmap2(addr, len, prot, flags, fd, pgoff, PAGE_SHIFT-12);
>> }
>> 
>> +#ifdef CONFIG_COMPAT
>> +COMPAT_SYSCALL_DEFINE6(mmap2,
>> +		       unsigned long, addr, size_t, len,
>> +		       unsigned long, prot, unsigned long, flags,
>> +		       unsigned long, fd, unsigned long, pgoff)
>> +{
>> +	/* This should remain 12 even if PAGE_SIZE changes */
>> +	return do_mmap2(addr, len, prot, flags, fd, pgoff << 12, PAGE_SHIFT-12);
>> +}
>> +#endif
>> +
>> SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len,
>> 		unsigned long, prot, unsigned long, flags,
>> 		unsigned long, fd, off_t, offset)
>> -- 
>> 2.34.1
>