From 9a7cb556eef7cb75b31d0bc05f73c6338dfd8e49 Mon Sep 17 00:00:00 2001

From: Richard Henderson <rth@redhat.com>

Date: Fri, 30 May 2014 13:57:04 -0400

Subject: [PATCH] aarch64: Backport syscall rewrite

From commits:

a60339aaff82beadea6f580e587d64052cb5e3b8 Fix handling of nocancel syscall...

3612eb8f25d978e7e4ac536a34098091f737161c Merge rtld_errno offset w/ mem ref

a6b3657be6bc5067aeec98d990f60765361c6557 Merge __local_multiple_threads ofs...

c69abcee726a6f63d9e5e8f0d9dcc79374ee3ef8 Fix DO_CALL block comment

6e6c2d01ebb1ef839675c7151d2a114f53663386 Remove DOARGS/UNDOARGS macros

ca3cfa40c16ef34c74951a07a57cfcbcd58898b1 Tidy syscall error check

af4e8ef9443e258ebeb0ddf3c5c9579f24dfacd5 Tabify sysdep-cancel.h

a8b4f04ad7dff4f39797a7ab7f8babda54266026 Share code in sysdep-cancel.h

645d44abe3ca6253a9d4762f092e4a1b9d294b11 Pass regno parameter to SINGLE_THREAD_P

b5be4597716eff94149f5529c8eb2cd3b4296188 Improve syscall-cancel stack frame

74f31c18593111725478a991b395ae45661985a3 Fix error return from __ioctl

f0712b543eaddeca8fc6d7a8eb6b5b8d24105ce2 Remove PSEUDO_RET

And a not-yet-committed cleanup to clone.S.

---

 ports/sysdeps/unix/sysv/linux/aarch64/clone.S      |  51 +++---

 ports/sysdeps/unix/sysv/linux/aarch64/ioctl.S      |  13 +-

 .../unix/sysv/linux/aarch64/nptl/localplt.data     |   1 -

 .../unix/sysv/linux/aarch64/nptl/sysdep-cancel.h   | 189 +++++++--------------

 ports/sysdeps/unix/sysv/linux/aarch64/syscall.S    |   4 +-

 ports/sysdeps/unix/sysv/linux/aarch64/sysdep.h     |  84 ++-------

 ports/sysdeps/unix/sysv/linux/aarch64/vfork.S      |   4 +-

 7 files changed, 108 insertions(+), 238 deletions(-)

diff --git glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/clone.S glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/clone.S

index 8be1464..d5c31f3 100644

--- glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/clone.S

+++ glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/clone.S

@@ -39,46 +39,43 @@

  */

         .text

 ENTRY(__clone)

+	/* Save args for the child.  */

+	mov	x10, x0

+	mov	x11, x2

+	mov	x12, x3

+	

 	/* Sanity check args.  */

-	cbz	x0, 1f

-	cbz	x1, 1f

-	/* Insert the args onto the new stack.  */

-	stp	x0, x3, [x1, #-16]!	/* Fn, arg.  */

+	mov	x0, #-EINVAL

+	cbz	x10, .Lsyscall_error

+	cbz	x1, .Lsyscall_error

 	/* Do the system call.  */

+	/* X0:flags, x1:newsp, x2:parenttidptr, x3:newtls, x4:childtid.  */

 	mov	x0, x2                  /* flags  */

-

 	/* New sp is already in x1.  */

 	mov	x2, x4			/* ptid  */

 	mov	x3, x5			/* tls  */

 	mov	x4, x6			/* ctid  */

-#ifdef RESET_PID

-	/* We rely on the kernel preserving the argument regsiters across a

-	   each system call so that we can inspect the flags against after

-	   the clone call.  */

-	mov	x5, x0

-#endif

-

 	mov	x8, #SYS_ify(clone)

-	/* X0:flags, x1:newsp, x2:parenttidptr, x3:newtls, x4:childtid.  */

 	svc	0x0

-	cfi_endproc

 	cmp	x0, #0

-	beq	2f

-	blt	C_SYMBOL_NAME(__syscall_error)

+	beq	thread_start

+	blt	.Lsyscall_error

 	RET

-1:	mov	x0, #-EINVAL

-	b	syscall_error

+PSEUDO_END (__clone)

-2:

+	.align	4

+	.type	thread_start, %function

+thread_start:

 	cfi_startproc

 	cfi_undefined (x30)

 	mov	x29, 0

+

 #ifdef RESET_PID

-	tbnz	x5, #CLONE_THREAD_BIT, 3f

+	tbnz	x11, #CLONE_THREAD_BIT, 3f

 	mov	x0, #-1

-	tbnz	x5, #CLONE_VM_BIT, 2f

+	tbnz	x11, #CLONE_VM_BIT, 2f

 	mov	x8, #SYS_ify(getpid)

 	svc	0x0

 2:

@@ -86,18 +83,16 @@ ENTRY(__clone)

 	sub	x1, x1, #PTHREAD_SIZEOF

 	str	w0, [x1, #PTHREAD_PID_OFFSET]

 	str	w0, [x1, #PTHREAD_TID_OFFSET]

-

 3:

 #endif

-	/* Pick the function arg and call address from the stack and

-	   execute.  */

-	ldp	x1, x0, [sp], #16

-	blr	x1

+

+	/* Pick the function arg execute.  */

+	mov	x0, x12

+	blr	x10

 	/* We are done, pass the return value through x0.  */

 	b	HIDDEN_JUMPTARGET(_exit)

 	cfi_endproc

-	cfi_startproc

-PSEUDO_END (__clone)

+	.size	thread_start, .-thread_start

 weak_alias (__clone, clone)

diff --git glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/ioctl.S glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/ioctl.S

index f01fb84..be6c026 100644

--- glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/ioctl.S

+++ glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/ioctl.S

@@ -20,13 +20,12 @@

 	.text

 ENTRY(__ioctl)

-	movz	x8, #__NR_ioctl

-        sxtw	x0, w0

-        svc	#0x0

-	cmn	x0, #0x1, lsl #12

-	b.hi	C_SYMBOL_NAME(__syscall_error)

+	mov	x8, #__NR_ioctl

+	sxtw	x0, w0

+	svc	#0x0

+	cmn	x0, #4095

+	b.cs	.Lsyscall_error

 	ret

-

-	PSEUDO_END (__ioctl)

+PSEUDO_END (__ioctl)

 weak_alias (__ioctl, ioctl)

diff --git glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data

index 84af95d..dfca9a7 100644

--- glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data

+++ glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/nptl/localplt.data

@@ -12,4 +12,3 @@ libm.so: matherr

 libm.so: __signbit

 libm.so: __signbitf

 libm.so: __signbitl

-libpthread.so: __errno_location

diff --git glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/nptl/sysdep-cancel.h glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/nptl/sysdep-cancel.h

index e0e5cc0..a3b9284 100644

--- glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/nptl/sysdep-cancel.h

+++ glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/nptl/sysdep-cancel.h

@@ -26,119 +26,60 @@

 # undef PSEUDO

 # define PSEUDO(name, syscall_name, args)				\

-  .section ".text";							\

-  .type __##syscall_name##_nocancel,%function;				\

-  .globl __##syscall_name##_nocancel;					\

-  __##syscall_name##_nocancel:						\

-    cfi_startproc;							\

-    DO_CALL (syscall_name, args);					\

-    PSEUDO_RET;								\

-    cfi_endproc;							\

-    .size __##syscall_name##_nocancel,.-__##syscall_name##_nocancel;	\

-  ENTRY (name);								\

-    SINGLE_THREAD_P;							\

-    DOARGS_##args;							\

-    bne .Lpseudo_cancel;						\

-    DO_CALL (syscall_name, 0);						\

-    UNDOARGS_##args;							\

-    cmn x0, 4095;							\

-    PSEUDO_RET;								\

-  .Lpseudo_cancel:							\

-    DOCARGS_##args;	/* save syscall args etc. around CENABLE.  */	\

-    CENABLE;								\

-    mov x16, x0;	/* put mask in safe place.  */			\

-    UNDOCARGS_##args;	/* restore syscall args.  */			\

-    mov x8, SYS_ify (syscall_name);	/* do the call.  */		\

-    svc	0;								\

-    str x0, [sp, -16]!;	/* save syscall return value.  */		\

-    cfi_adjust_cfa_offset (16);						\

-    mov x0, x16;	 /* get mask back.  */				\

-    CDISABLE;								\

-    ldr x0, [sp], 16;							\

-    cfi_adjust_cfa_offset (-16);					\

-    ldr x30, [sp], 16;							\

-    cfi_adjust_cfa_offset (-16);					\

-    cfi_restore (x30);							\

-    UNDOARGS_##args;							\

-    cmn x0, 4095;

-

-# define DOCARGS_0							\

-	str x30, [sp, -16]!;						\

-	cfi_adjust_cfa_offset (16);					\

-	cfi_rel_offset (x30, 0)

+	.section ".text";						\

+ENTRY (__##syscall_name##_nocancel);					\

+.Lpseudo_nocancel:							\

+	DO_CALL (syscall_name, args);					\

+.Lpseudo_finish:							\

+	cmn	x0, 4095;						\

+	b.cs	.Lsyscall_error;					\

+	.subsection 2;							\

+	.size __##syscall_name##_nocancel,.-__##syscall_name##_nocancel; \

+ENTRY (name);								\

+	SINGLE_THREAD_P(16);						\

+	cbz	w16, .Lpseudo_nocancel;					\

+	/* Setup common stack frame no matter the number of args.	\

+	   Also save the first arg, since it's basically free.  */	\

+	stp	x30, x0, [sp, -64]!;					\

+	cfi_adjust_cfa_offset (64);					\

+	cfi_rel_offset (x30, 0);					\

+	DOCARGS_##args;		/* save syscall args around CENABLE.  */ \

+	CENABLE;							\

+	mov	x16, x0;	/* save mask around syscall.  */	\

+	UNDOCARGS_##args;	/* restore syscall args.  */		\

+	DO_CALL (syscall_name, args);					\

+	str	x0, [sp, 8];	/* save result around CDISABLE.  */	\

+	mov	x0, x16;	/* restore mask for CDISABLE.  */	\

+	CDISABLE;							\

+	/* Break down the stack frame, restoring result at once.  */	\

+	ldp	x30, x0, [sp], 64;					\

+	cfi_adjust_cfa_offset (-64);					\

+	cfi_restore (x30);						\

+	b	.Lpseudo_finish;					\

+	cfi_endproc;							\

+	.size	name, .-name;						\

+	.previous

+

+# undef PSEUDO_END

+# define PSEUDO_END(name)						\

+	SYSCALL_ERROR_HANDLER;						\

+	cfi_endproc

+

+# define DOCARGS_0

+# define DOCARGS_1

+# define DOCARGS_2	str x1, [sp, 16]

+# define DOCARGS_3	stp x1, x2, [sp, 16]

+# define DOCARGS_4	DOCARGS_3; str x3, [sp, 32]

+# define DOCARGS_5	DOCARGS_3; stp x3, x4, [sp, 32]

+# define DOCARGS_6	DOCARGS_5; str x5, [sp, 48]

 # define UNDOCARGS_0

-

-# define DOCARGS_1							\

-	DOCARGS_0;							\

-	str x0, [sp, -16]!;						\

-	cfi_adjust_cfa_offset (16);					\

-	cfi_rel_offset (x0, 0)

-

-# define UNDOCARGS_1							\

-	ldr x0, [sp], 16;						\

-	cfi_restore (x0);						\

-	cfi_adjust_cfa_offset (-16);					\

-

-# define DOCARGS_2							\

-	DOCARGS_1;							\

-	str x1, [sp, -16]!;						\

-	cfi_adjust_cfa_offset (16);					\

-	cfi_rel_offset (x1, 0)

-

-# define UNDOCARGS_2							\

-	ldr x1, [sp], 16;						\

-	cfi_restore (x1);						\

-	cfi_adjust_cfa_offset (-16);					\

-	UNDOCARGS_1

-

-# define DOCARGS_3							\

-	DOCARGS_2;							\

-	str x2, [sp, -16]!;						\

-	cfi_adjust_cfa_offset (16);					\

-	cfi_rel_offset (x2, 0)

-

-# define UNDOCARGS_3							\

-	ldr x2, [sp], 16;						\

-	cfi_restore (x2);						\

-	cfi_adjust_cfa_offset (-16);					\

-	UNDOCARGS_2

-

-# define DOCARGS_4							\

-	DOCARGS_3;							\

-	str x3, [sp, -16]!;						\

-	cfi_adjust_cfa_offset (16);					\

-	cfi_rel_offset (x3, 0)

-

-# define UNDOCARGS_4							\

-	ldr x3, [sp], 16;						\

-	cfi_restore (x3);						\

-	cfi_adjust_cfa_offset (-16);					\

-	UNDOCARGS_3

-

-# define DOCARGS_5							\

-	DOCARGS_4;							\

-	str x4, [sp, -16]!;						\

-	cfi_adjust_cfa_offset (16);					\

-	cfi_rel_offset (x4, 0)

-

-# define UNDOCARGS_5							\

-	ldr x4, [sp], 16;						\

-	cfi_restore (x4);						\

-	cfi_adjust_cfa_offset (-16);					\

-	UNDOCARGS_4

-

-# define DOCARGS_6							\

-	DOCARGS_5;							\

-	str x5, [sp, -16]!;						\

-	cfi_adjust_cfa_offset (16);					\

-	cfi_rel_offset (x5, 0)

-

-# define UNDOCARGS_6							\

-	ldr x5, [sp], 16;						\

-	cfi_restore (x5);						\

-	cfi_adjust_cfa_offset (-16);					\

-	UNDOCARGS_5

+# define UNDOCARGS_1	ldr x0, [sp, 8]

+# define UNDOCARGS_2	ldp x0, x1, [sp, 8]

+# define UNDOCARGS_3	UNDOCARGS_1; ldp x1, x2, [sp, 16]

+# define UNDOCARGS_4	UNDOCARGS_2; ldp x2, x3, [sp, 24]

+# define UNDOCARGS_5	UNDOCARGS_3; ldp x3, x4, [sp, 32]

+# define UNDOCARGS_6	UNDOCARGS_4; ldp x4, x5, [sp, 40]

 # ifdef IS_IN_libpthread

 #  define CENABLE	bl __pthread_enable_asynccancel

@@ -160,11 +101,9 @@

 extern int __local_multiple_threads attribute_hidden;

 #   define SINGLE_THREAD_P __builtin_expect (__local_multiple_threads == 0, 1)

 #  else

-#   define SINGLE_THREAD_P						\

-  adrp	x16, __local_multiple_threads;					\

-  add	x16, x16, #:lo12:__local_multiple_threads;			\

-  ldr	x16, [x16];							\

-  cmp	x16, 0;

+#   define SINGLE_THREAD_P(R)						\

+	adrp	x##R, __local_multiple_threads;				\

+	ldr	w##R, [x##R, :lo12:__local_multiple_threads]

 #  endif

 # else

 /*  There is no __local_multiple_threads for librt, so use the TCB.  */

@@ -173,20 +112,10 @@ extern int __local_multiple_threads attribute_hidden;

   __builtin_expect (THREAD_GETMEM (THREAD_SELF,				\

 				   header.multiple_threads) == 0, 1)

 #  else

-#   define SINGLE_THREAD_P						\

-  stp	x0, x30, [sp, -16]!;						\

-  cfi_adjust_cfa_offset (16);						\

-  cfi_rel_offset (x0, 0);						\

-  cfi_rel_offset (x30, 8);						\

-  bl	__read_tp;							\

-  sub	x0, x0, PTHREAD_SIZEOF;						\

-  ldr	x16, [x0, PTHREAD_MULTIPLE_THREADS_OFFSET];			\

-  ldp	x0, x30, [sp], 16;						\

-  cfi_restore (x0);							\

-  cfi_restore (x30);							\

-  cfi_adjust_cfa_offset (-16);						\

-  cmp	x16, 0

-#   define SINGLE_THREAD_P_PIC(x) SINGLE_THREAD_P

+#   define SINGLE_THREAD_P(R)						\

+	mrs	x##R, tpidr_el0;					\

+	sub	x##R, x##R, PTHREAD_SIZEOF;				\

+	ldr	w##R, [x##R, PTHREAD_MULTIPLE_THREADS_OFFSET]

 #  endif

 # endif

diff --git glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/syscall.S glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/syscall.S

index 574fdf1..fac6416 100644

--- glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/syscall.S

+++ glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/syscall.S

@@ -37,8 +37,6 @@ ENTRY (syscall)

 	mov	x6, x7

 	svc	0x0

 	cmn	x0, #4095

-	b.cs	1f

+	b.cs	.Lsyscall_error

 	RET

-1:

-	b	SYSCALL_ERROR

 PSEUDO_END (syscall)

diff --git glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/sysdep.h glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/sysdep.h

index 713bf7d..9961c03 100644

--- glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/sysdep.h

+++ glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/sysdep.h

@@ -58,19 +58,8 @@

   .text;								      \

   ENTRY (name);								      \

     DO_CALL (syscall_name, args);					      \

-    cmn x0, #4095;

-

-/* Notice the use of 'RET' instead of 'ret' the assembler is case

-   insensitive and eglibc already uses the preprocessor symbol 'ret'

-   so we use the upper case 'RET' to force through a ret instruction

-   to the assembler */

-# define PSEUDO_RET							      \

-    b.cs 1f;								      \

-    RET;								      \

-    1:                                                                        \

-    b SYSCALL_ERROR

-# undef ret

-# define ret PSEUDO_RET

+    cmn x0, #4095;							      \

+    b.cs .Lsyscall_error

 # undef	PSEUDO_END

 # define PSEUDO_END(name)						      \

@@ -83,15 +72,7 @@

   ENTRY (name);								      \

     DO_CALL (syscall_name, args);

-/* Notice the use of 'RET' instead of 'ret' the assembler is case

-   insensitive and eglibc already uses the preprocessor symbol 'ret'

-   so we use the upper case 'RET' to force through a ret instruction

-   to the assembler */

-# define PSEUDO_RET_NOERRNO						      \

-    RET;

-

-# undef ret_NOERRNO

-# define ret_NOERRNO PSEUDO_RET_NOERRNO

+# define ret_NOERRNO ret

 # undef	PSEUDO_END_NOERRNO

 # define PSEUDO_END_NOERRNO(name)					      \

@@ -109,47 +90,38 @@

 # define PSEUDO_END_ERRVAL(name) \

   END (name)

-# define ret_ERRVAL PSEUDO_RET_NOERRNO

+# define ret_ERRVAL ret

+# define SYSCALL_ERROR  .Lsyscall_error

 # if NOT_IN_libc

-#  define SYSCALL_ERROR __local_syscall_error

 #  if RTLD_PRIVATE_ERRNO

 #   define SYSCALL_ERROR_HANDLER				\

-__local_syscall_error:						\

+.Lsyscall_error:						\

 	adrp	x1, C_SYMBOL_NAME(rtld_errno);			\

-	add	x1, x1, #:lo12:C_SYMBOL_NAME(rtld_errno);	\

 	neg     w0, w0;						\

-	str     w0, [x1];					\

+	str     w0, [x1, :lo12:C_SYMBOL_NAME(rtld_errno)];	\

 	mov	x0, -1;						\

 	RET;

 #  else

 #   define SYSCALL_ERROR_HANDLER				\

-__local_syscall_error:						\

-	stp     x29, x30, [sp, -32]!;				\

-	cfi_adjust_cfa_offset (32);				\

-	cfi_rel_offset (x29, 0);				\

-	cfi_rel_offset (x30, 8);				\

-        add     x29, sp, 0;					\

-        str     x19, [sp,16];					\

-	neg	x19, x0;					\

-	bl	C_SYMBOL_NAME(__errno_location);		\

-	str	x19, [x0];					\

+.Lsyscall_error:						\

+	adrp	x1, :gottprel:errno;				\

+	neg	w2, w0;						\

+	ldr	x1, [x1, :gottprel_lo12:errno];			\

+	mrs	x3, tpidr_el0;					\

 	mov	x0, -1;						\

-        ldr     x19, [sp,16];					\

-        ldp     x29, x30, [sp], 32;				\

-	cfi_adjust_cfa_offset (-32);				\

-	cfi_restore (x29);					\

-	cfi_restore (x30);					\

+	str	w2, [x1, x3];					\

 	RET;

 #  endif

 # else

-#  define SYSCALL_ERROR_HANDLER	/* Nothing here; code in sysdep.S is used.  */

-#  define SYSCALL_ERROR __syscall_error

+#  define SYSCALL_ERROR_HANDLER					\

+.Lsyscall_error:						\

+	b	__syscall_error;

 # endif

 /* Linux takes system call args in registers:

-	syscall number	in the SVC instruction

+	syscall number	x8

 	arg 1		x0

 	arg 2		x1

 	arg 3		x2

@@ -177,28 +149,8 @@ __local_syscall_error:						\

 # undef	DO_CALL

 # define DO_CALL(syscall_name, args)		\

-    DOARGS_##args				\

     mov x8, SYS_ify (syscall_name);		\

-    svc 0;					\

-    UNDOARGS_##args

-

-# define DOARGS_0 /* nothing */

-# define DOARGS_1 /* nothing */

-# define DOARGS_2 /* nothing */

-# define DOARGS_3 /* nothing */

-# define DOARGS_4 /* nothing */

-# define DOARGS_5 /* nothing */

-# define DOARGS_6 /* nothing */

-# define DOARGS_7 /* nothing */

-

-# define UNDOARGS_0 /* nothing */

-# define UNDOARGS_1 /* nothing */

-# define UNDOARGS_2 /* nothing */

-# define UNDOARGS_3 /* nothing */

-# define UNDOARGS_4 /* nothing */

-# define UNDOARGS_5 /* nothing */

-# define UNDOARGS_6 /* nothing */

-# define UNDOARGS_7 /* nothing */

+    svc 0

 #else /* not __ASSEMBLER__ */

diff --git glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/vfork.S glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/vfork.S

index f2dc49b..3fb68b9 100644

--- glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/vfork.S

+++ glibc-2.17-c758a686/ports/sysdeps/unix/sysv/linux/aarch64/vfork.S

@@ -38,10 +38,8 @@ ENTRY (__vfork)

 	RESTORE_PID

 #endif

 	cmn	x0, #4095

-	b.cs    1f

+	b.cs    .Lsyscall_error

 	RET

-1:

-	b	SYSCALL_ERROR

 PSEUDO_END (__vfork)

 libc_hidden_def (__vfork)

-- 

1.8.3.1