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* [PATCH][AArch64] Fix link error for ioctl syscall wrapper.
@ 2013-05-12 12:00 Marcus Shawcroft
  0 siblings, 0 replies; only message in thread
From: Marcus Shawcroft @ 2013-05-12 12:00 UTC (permalink / raw)
  To: libc-ports

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The ioctl() and clone() system call wrappers for AArch64 are currently written
to use a conditional branch to reach the sycall error handler when the
relevant system call returns an error value.  The use of conditional
branch for this purpose is inappropriate due to the limited range of
these instructions.   The generated syscall wrappers take care to use
the unconditional branch form, which has greater range.

This patch corrects the behavior of both wrappers.

I shall commit this patch shortly.


Proposed ChangeLog:

2013-05-12  Marcus Shawcroft  <>

        * sysdeps/unix/sysv/linux/aarch64/clone.S (__clone):
        Do not call sycall_error directly with a confitional branch.

        * sysdeps/unix/sysv/linux/aarch64/ioctl.S (__ioctl):
        Do not call sycall_error directly with a confitional branch.

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diff --git a/ports/sysdeps/unix/sysv/linux/aarch64/clone.S b/ports/sysdeps/unix/sysv/linux/aarch64/clone.S
index 999ecf2..b359e6e 100644
--- a/ports/sysdeps/unix/sysv/linux/aarch64/clone.S
+++ b/ports/sysdeps/unix/sysv/linux/aarch64/clone.S
@@ -65,9 +65,10 @@ ENTRY(__clone)
 	svc	0x0
 	cmp	x0, #0
 	beq	2f
-	blt	C_SYMBOL_NAME(__syscall_error)
+	blt	3f
 1:	mov	x0, #-EINVAL
 	b	syscall_error
diff --git a/ports/sysdeps/unix/sysv/linux/aarch64/ioctl.S b/ports/sysdeps/unix/sysv/linux/aarch64/ioctl.S
index b089bb5..2e08cf7 100644
--- a/ports/sysdeps/unix/sysv/linux/aarch64/ioctl.S
+++ b/ports/sysdeps/unix/sysv/linux/aarch64/ioctl.S
@@ -24,9 +24,7 @@ ENTRY(__ioctl)
         sxtw	x0, w0
         svc	#0x0
 	cmn	x0, #0x1, lsl #12
-	b.hi	C_SYMBOL_NAME(__syscall_error)
-	ret
 	PSEUDO_END (__ioctl)
 weak_alias (__ioctl, ioctl)

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2013-05-12 12:00 [PATCH][AArch64] Fix link error for ioctl syscall wrapper Marcus Shawcroft

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