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From: Venkataramanan Kumar <venkataramanan.kumar@linaro.org>
To: Marcus Shawcroft <marcus.shawcroft@gmail.com>
Cc: libc-ports@sourceware.org, Patch Tracking <patch@linaro.org>
Subject: Re: [PATCH] [AARCH64]: Pointer mangling support for Aarch64
Date: Tue, 31 Dec 2013 05:15:00 -0000	[thread overview]
Message-ID: <CAJK_mQ0QwoSEJU+GWG=zibWQ8VAmj6+gvB3FqY9Y7jEBa6w8gQ@mail.gmail.com> (raw)
In-Reply-To: <CAFqB+PyA1=MZ4gTZQ4VX9q7rG7ra-AEeTXXDm4Rz34fyMxLyjA@mail.gmail.com>

[-- Attachment #1: Type: text/plain, Size: 1847 bytes --]

Hi Marcus,

Thank you for reviewing the patch.
I have incorporated your review comments.

(Snip)
+#ifdef PTR_DEMANGLE
+  PTR_DEMANGLE (sp);
+#endif
Nested #if should have indentation between # and if.
(Snip)

In ports/sysdeps/aarch64/jmpbuf-offsets.h, should I need to add space
between # and if?
Reading the glibc coding style,  I understood it as outer #ifndef
__ASSEMBLER__ will not increase indentation level.

if it is Ok, can you please commit on my behalf since I don't have write access.

ChangeLog.aarch64:
-----------------------------
2013-12-31  Venkataramanan Kumar  <venkataramanan.kumar@linaro.org>

* sysdeps/aarch64/__longjmp.S (__longjmp): Demangle sp
        and lr when restoring register values.
* sysdeps/aarch64/setjmp.S (__sigsetjmp): Mangle sp and lr
before storing register values.
* sysdeps/arm/jmpbuf-unwind.h (_jmpbuf_sp): Remove.
* sysdeps/aarch64/jmpbuf-offsets.h (_jmpbuf_sp): Add.
(JB_FRAME_ADDRESS): call  _jmpbuf_sp.
* sysdeps/aarch64/sysdep.h (LDST_PCREL) : New macros.
(LDST_GLOBAL): Likewise.
* sysdeps/unix/sysv/linux/aarch64/sysdep.h (PTR_MANGLE): New macro.
(PTR_DEMANGLE): Likewise.
(PTR_MANGLE2): Likewise.
(PTR_DEMANGLE2): Likewise.

regards,
Venkat.


On 31 December 2013 03:50, Marcus Shawcroft <marcus.shawcroft@gmail.com> wrote:
> Hi, Couple of nits:
>
> On 30 December 2013 05:00, Venkataramanan Kumar
> <venkataramanan.kumar@linaro.org> wrote:
>
> +#  define PTR_MANGLE(dst, src, guard, tmp)                              \
> +  LDST_PCREL(ldr, guard, tmp, C_SYMBOL_NAME(__pointer_chk_guard_local)); \
> +  PTR_MANGLE2(dst, src, guard)
>
> Space before ( in macro invocations.
>
> +#ifdef PTR_DEMANGLE
> +  PTR_DEMANGLE (sp);
> +#endif
>
> Nested #if should have indentation between # and if.
>
> +/* Pointer mangling is support for AArch64.  */
>
> support -> supported
>
> Otherwise OK
> /Marcus

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diff --git a/ports/sysdeps/aarch64/__longjmp.S b/ports/sysdeps/aarch64/__longjmp.S
index ffd30a2..426edc0 100644
--- a/ports/sysdeps/aarch64/__longjmp.S
+++ b/ports/sysdeps/aarch64/__longjmp.S
@@ -50,8 +50,12 @@ ENTRY (__longjmp)
 	ldp	x23, x24, [x0, #JB_X23<<3]
 	ldp	x25, x26, [x0, #JB_X25<<3]
 	ldp	x27, x28, [x0, #JB_X27<<3]
+#ifdef PTR_DEMANGLE
+	ldp	x29,  x4, [x0, #JB_X29<<3]
+	PTR_DEMANGLE (x30, x4, x3, x2)
+#else
 	ldp	x29, x30, [x0, #JB_X29<<3]
-
+#endif
 	ldp	 d8,  d9, [x0, #JB_D8<<3]
 	ldp	d10, d11, [x0, #JB_D10<<3]
 	ldp	d12, d13, [x0, #JB_D12<<3]
@@ -87,8 +91,12 @@ ENTRY (__longjmp)
 	cfi_same_value(d13)
 	cfi_same_value(d14)
 	cfi_same_value(d15)
-
-	ldr	x5,  [x0, #JB_SP<<3]
+#ifdef PTR_DEMANGLE
+	ldr	x4, [x0, #JB_SP<<3]
+	PTR_DEMANGLE (x5, x4, x3, x2)
+#else
+	ldr	x5, [x0, #JB_SP<<3]
+#endif
 	mov	sp, x5
 	cmp	x1, #0
 	mov	x0, #1
diff --git a/ports/sysdeps/aarch64/jmpbuf-offsets.h b/ports/sysdeps/aarch64/jmpbuf-offsets.h
index ed5f42a..1392c41 100644
--- a/ports/sysdeps/aarch64/jmpbuf-offsets.h
+++ b/ports/sysdeps/aarch64/jmpbuf-offsets.h
@@ -39,6 +39,22 @@
 #define JB_D14		 20
 #define JB_D15		 21
 
+#ifndef  __ASSEMBLER__
+#include <setjmp.h>
+#include <stdint.h>
+#include <sysdep.h>
+
+static inline uintptr_t __attribute__ ((unused))
+_jmpbuf_sp (__jmp_buf jmpbuf)
+{
+  uintptr_t sp = jmpbuf[JB_SP];
+#ifdef PTR_DEMANGLE
+  PTR_DEMANGLE (sp);
+#endif
+  return sp;
+}
+#endif
+
 /* Helper for generic ____longjmp_chk(). */
 #define JB_FRAME_ADDRESS(buf) \
-  ((void *) (buf[JB_SP]))
+  ((void *) _jmpbuf_sp (buf))
diff --git a/ports/sysdeps/aarch64/jmpbuf-unwind.h b/ports/sysdeps/aarch64/jmpbuf-unwind.h
index 087e1b6..375decb 100644
--- a/ports/sysdeps/aarch64/jmpbuf-unwind.h
+++ b/ports/sysdeps/aarch64/jmpbuf-unwind.h
@@ -29,16 +29,6 @@
 #define _JMPBUF_CFA_UNWINDS_ADJ(jmpbuf, context, adj) \
   _JMPBUF_UNWINDS_ADJ (jmpbuf, (void *) _Unwind_GetCFA (context), adj)
 
-static inline uintptr_t __attribute__ ((unused))
-_jmpbuf_sp (__jmp_buf jmpbuf)
-{
-  uintptr_t sp = jmpbuf[JB_SP];
-#ifdef PTR_DEMANGLE
-  PTR_DEMANGLE (sp);
-#endif
-  return sp;
-}
-
 #define _JMPBUF_UNWINDS_ADJ(_jmpbuf, _address, _adj) \
   ((uintptr_t) (_address) - (_adj) < _jmpbuf_sp (_jmpbuf) - (_adj))
 
diff --git a/ports/sysdeps/aarch64/setjmp.S b/ports/sysdeps/aarch64/setjmp.S
index 10e0709..fb90cf2 100644
--- a/ports/sysdeps/aarch64/setjmp.S
+++ b/ports/sysdeps/aarch64/setjmp.S
@@ -39,13 +39,25 @@ ENTRY (__sigsetjmp)
 	stp	x23, x24, [x0, #JB_X23<<3]
 	stp	x25, x26, [x0, #JB_X25<<3]
 	stp	x27, x28, [x0, #JB_X27<<3]
+
+#ifdef PTR_MANGLE
+	PTR_MANGLE (x4, x30, x3, x2)
+	stp	x29,  x4, [x0, #JB_X29<<3]
+#else
 	stp	x29, x30, [x0, #JB_X29<<3]
+#endif
 	stp	 d8,  d9, [x0, #JB_D8<<3]
 	stp	d10, d11, [x0, #JB_D10<<3]
 	stp	d12, d13, [x0, #JB_D12<<3]
 	stp	d14, d15, [x0, #JB_D14<<3]
+#ifdef PTR_MANGLE
+	mov	x4, sp
+	PTR_MANGLE (x5, x4, x3, x2)
+	str	x5, [x0, #JB_SP<<3]
+#else
 	mov	x2,  sp
 	str	x2,  [x0, #JB_SP<<3]
+#endif
 #if defined NOT_IN_libc && defined IS_IN_rtld
 	/* In ld.so we never save the signal mask */
 	mov	w0, #0
diff --git a/ports/sysdeps/aarch64/sysdep.h b/ports/sysdeps/aarch64/sysdep.h
index 9349471..5fb7173 100644
--- a/ports/sysdeps/aarch64/sysdep.h
+++ b/ports/sysdeps/aarch64/sysdep.h
@@ -78,6 +78,17 @@
 # define L(name)         .L##name
 #endif
 
+/* Load or store to/from a pc-relative EXPR into/from R, using T.  */
+#define LDST_PCREL(OP, R, T, EXPR)  \
+	adrp	T, EXPR;	    \
+	OP	R, [T, #:lo12:EXPR];\
+
+/* Load or store to/from a got-relative EXPR into/from R, using T.  */
+#define LDST_GLOBAL(OP, R, T, EXPR)     \
+	adrp	T, :got:EXPR;		\
+	ldr	T, [T, #:got_lo12:EXPR];\
+	OP	R, [T];
+
 /* Since C identifiers are not normally prefixed with an underscore
    on this system, the asm identifier `syscall_error' intrudes on the
    C name space.  Make sure we use an innocuous name.  */
diff --git a/ports/sysdeps/unix/sysv/linux/aarch64/sysdep.h b/ports/sysdeps/unix/sysv/linux/aarch64/sysdep.h
index 9a7b167..c596055 100644
--- a/ports/sysdeps/unix/sysv/linux/aarch64/sysdep.h
+++ b/ports/sysdeps/unix/sysv/linux/aarch64/sysdep.h
@@ -371,8 +371,44 @@ __local_syscall_error:						\
 
 #endif	/* __ASSEMBLER__ */
 
-/* Pointer mangling is not yet supported for AArch64.  */
-#define PTR_MANGLE(var) (void) (var)
-#define PTR_DEMANGLE(var) (void) (var)
+/* Pointer mangling is supported for AArch64.  */
+#if (defined NOT_IN_libc && defined IS_IN_rtld) || \
+  (!defined SHARED && (!defined NOT_IN_libc || defined IS_IN_libpthread))
+# ifdef __ASSEMBLER__
+#  define PTR_MANGLE(dst, src, guard, tmp)                                \
+  LDST_PCREL (ldr, guard, tmp, C_SYMBOL_NAME(__pointer_chk_guard_local)); \
+  PTR_MANGLE2 (dst, src, guard)
+/* Use PTR_MANGLE2 for efficiency if guard is already loaded.  */
+#  define PTR_MANGLE2(dst, src, guard)\
+  eor dst, src, guard
+#  define PTR_DEMANGLE(dst, src, guard, tmp)\
+  PTR_MANGLE (dst, src, guard, tmp)
+#  define PTR_DEMANGLE2(dst, src, guard)\
+  PTR_MANGLE2 (dst, src, guard)
+# else
+extern uintptr_t __pointer_chk_guard_local attribute_relro attribute_hidden;
+#  define PTR_MANGLE(var) \
+  (var) = (__typeof (var)) ((uintptr_t) (var) ^ __pointer_chk_guard_local)
+#  define PTR_DEMANGLE(var)     PTR_MANGLE (var)
+# endif
+#else
+# ifdef __ASSEMBLER__
+#  define PTR_MANGLE(dst, src, guard, tmp)                             \
+  LDST_GLOBAL (ldr, guard, tmp, C_SYMBOL_NAME(__pointer_chk_guard));   \
+  PTR_MANGLE2 (dst, src, guard)
+/* Use PTR_MANGLE2 for efficiency if guard is already loaded.  */
+#  define PTR_MANGLE2(dst, src, guard)\
+  eor dst, src, guard
+#  define PTR_DEMANGLE(dst, src, guard, tmp)\
+  PTR_MANGLE (dst, src, guard, tmp)
+#  define PTR_DEMANGLE2(dst, src, guard)\
+  PTR_MANGLE2 (dst, src, guard)
+# else
+extern uintptr_t __pointer_chk_guard attribute_relro;
+#  define PTR_MANGLE(var) \
+  (var) = (__typeof (var)) ((uintptr_t) (var) ^ __pointer_chk_guard)
+#  define PTR_DEMANGLE(var) PTR_MANGLE (var)
+# endif
+#endif
 
 #endif /* linux/aarch64/sysdep.h */

  reply	other threads:[~2013-12-31  5:15 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-12-26 12:25 Venkataramanan Kumar
2013-12-26 19:33 ` Richard Henderson
2013-12-27  7:48   ` Venkataramanan Kumar
2013-12-27 15:09     ` Richard Henderson
2013-12-30  5:00       ` Venkataramanan Kumar
2013-12-30 14:45         ` Richard Henderson
2013-12-30 15:36           ` Venkataramanan Kumar
2013-12-30 22:20         ` Marcus Shawcroft
2013-12-31  5:15           ` Venkataramanan Kumar [this message]
2014-01-01 17:42             ` Marcus Shawcroft
2014-01-06 18:11 ` Tom Tromey
2014-01-07 11:05   ` Venkataramanan Kumar
2014-01-07 12:17     ` Marcus Shawcroft
2014-01-07 18:10       ` Tom Tromey
2014-01-10  9:54         ` Will Newton
2014-01-20  9:01         ` Will Newton
2014-01-20 16:45           ` Tom Tromey
2014-01-20 17:02             ` Will Newton
2014-01-08 10:32       ` Venkataramanan Kumar
2014-01-10 10:40         ` Marcus Shawcroft

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