Re: git: 47ff149afaea - main - Move arm64 EENTRY uses before ENTRY

On 31 Mar 2023, at 17:00, Jessica Clarke <jrtc27@FreeBSD.org> wrote:
> On 31 Mar 2023, at 16:56, Andrew Turner <andrew@FreeBSD.org> wrote:
>> 
>> The branch main has been updated by andrew:
>> 
>> URL: https://cgit.FreeBSD.org/src/commit/?id=47ff149afaea6a403b8d044e26673bc3cd605fe4
>> 
>> commit 47ff149afaea6a403b8d044e26673bc3cd605fe4
>> Author:     Andrew Turner <andrew@FreeBSD.org>
>> AuthorDate: 2023-03-31 12:34:51 +0000
>> Commit:     Andrew Turner <andrew@FreeBSD.org>
>> CommitDate: 2023-03-31 15:45:31 +0000
>> 
>>   Move arm64 EENTRY uses before ENTRY
>> 
>>   The ENTRY macro adds instructions to the start of a function but not
>>   EENTRY. To use these instructions in both functions move the EENTRY
>>   use before the ENTRY use.
> 
> This doesn’t work. ENTRY is what has the .text and .align 2, so this
> could have the EENTRY symbols be unaligned or in the wrong section. In
> this specific case it happens to work, but in general this is broken
> and so your original problem needs fixing another way. Or I guess you
> could make both ENTRY and EENTRY include the .text and .align 2 (but on
> other architectures with variable-length instructions, or even on arm64
> were you to ever want to over-align functions, this would still be
> insufficient).

Ping.

Jess

>>   Sponsored by:   Arm Ltd
>> ---
>> sys/arm64/arm64/memcpy.S  | 4 ++--
>> sys/arm64/arm64/support.S | 8 ++++----
>> 2 files changed, 6 insertions(+), 6 deletions(-)
>> 
>> diff --git a/sys/arm64/arm64/memcpy.S b/sys/arm64/arm64/memcpy.S
>> index d5fbfa64e0fa..b394d6c1d30a 100644
>> --- a/sys/arm64/arm64/memcpy.S
>> +++ b/sys/arm64/arm64/memcpy.S
>> @@ -55,8 +55,8 @@
>>   The loop tail is handled by always copying 64 bytes from the end.
>> */
>> 
>> -ENTRY(memcpy)
>> EENTRY(memmove)
>> +ENTRY(memcpy)
>> 	add	srcend, src, count
>> 	add	dstend, dstin, count
>> 	cmp	count, 128
>> @@ -237,6 +237,6 @@ L(copy64_from_start):
>> 	stp	B_l, B_h, [dstin, 16]
>> 	stp	C_l, C_h, [dstin]
>> 	ret
>> -EEND(memmove)
>> END(memcpy)
>> +EEND(memmove)
>> 
>> diff --git a/sys/arm64/arm64/support.S b/sys/arm64/arm64/support.S
>> index 885af5676159..28ac1d553fbc 100644
>> --- a/sys/arm64/arm64/support.S
>> +++ b/sys/arm64/arm64/support.S
>> @@ -175,15 +175,15 @@ END(fueword32)
>> * long fueword(volatile const void *, int64_t *)
>> * int64_t fueword64(volatile const void *, int64_t *)
>> */
>> -ENTRY(fueword)
>> EENTRY(fueword64)
>> +ENTRY(fueword)
>> 	check_user_access 0, (VM_MAXUSER_ADDRESS-7), fsu_fault_nopcb
>> 	fsudata	ldtr, x0, 0
>> 	str	x0, [x1]		/* Save the data in kernel space */
>> 	mov	x0, #0			/* Success */
>> 	ret				/* Return */
>> -EEND(fueword64)
>> END(fueword)
>> +EEND(fueword64)
>> 
>> /*
>> * int subyte(volatile void *, int)
>> @@ -218,14 +218,14 @@ END(suword32)
>> /*
>> * int suword(volatile void *, long)
>> */
>> -ENTRY(suword)
>> EENTRY(suword64)
>> +ENTRY(suword)
>> 	check_user_access 0, (VM_MAXUSER_ADDRESS-7), fsu_fault_nopcb
>> 	fsudata	sttr, x1, 0
>> 	mov	x0, #0			/* Success */
>> 	ret				/* Return */
>> -EEND(suword64)
>> END(suword)
>> +EEND(suword64)
>> 
>> ENTRY(setjmp)
>> 	/* Store the stack pointer */