From: Roland McGrath <roland@hack.frob.com>
To: Joseph Myers <joseph@codesourcery.com>
Cc: libc-ports@sourceware.org
Subject: [PATCH 2/2 roland/arm-sfi-macros] ARM: sfi_sp assembler macro
Date: Wed, 13 Mar 2013 23:14:00 -0000 [thread overview]
Message-ID: <20130313231403.492372C09A@topped-with-meat.com> (raw)
In-Reply-To: Roland McGrath's message of Wednesday, 13 March 2013 16:08:41 -0700 <20130313230841.B880B2C097@topped-with-meat.com>
Another requirement of the arm-nacl ABI is that all explicit modifications
of sp take a special form. By "explicit" I mean not including push/pop or
any [sp...]! forms of loads or stores (or sp! forms of ldm/stm). I haven't
yet dealt with the dynamic linker support code, and other than that longjmp
is the only place that actually does any such sp modification.
See the previous message for pointers to the non-no-op definition of sfi_sp
that will be used by the arm-nacl configuration.
Thanks,
Roland
ports/ChangeLog.arm
* sysdeps/arm/sysdep.h [!ARM_SFI_MACROS] (sfi_sp): New macro.
* sysdeps/arm/__longjmp.S: Use it.
--- a/ports/sysdeps/arm/__longjmp.S
+++ b/ports/sysdeps/arm/__longjmp.S
@@ -36,7 +36,7 @@ ENTRY (__longjmp)
cfi_undefined (r4)
CHECK_SP (r4)
#endif
- sfi_breg ip, \
+ sfi_sp sfi_breg ip, \
ldmia \B!, JMP_BUF_REGLIST
cfi_restore (v1)
cfi_restore (v2)
--- a/ports/sysdeps/arm/sysdep.h
+++ b/ports/sysdeps/arm/sysdep.h
@@ -250,6 +250,11 @@
pld [\basereg, \offset]
.endm
+/* This macro precedes any instruction that directly changes the SP.
+ It's not needed for push/pop or for any kind of load or store that
+ implicitly changes the SP via the ! syntax. */
+# define sfi_sp /* Nothing to do. */
+
# endif
#endif /* __ASSEMBLER__ */
next prev parent reply other threads:[~2013-03-13 23:14 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-13 23:09 [PATCH 1/2 roland/arm-sfi-macros] ARM: sfi_breg " Roland McGrath
2013-03-13 23:14 ` Roland McGrath [this message]
2013-03-15 1:52 ` [PATCH 2/2 roland/arm-sfi-macros] ARM: sfi_sp " Joseph S. Myers
2013-03-15 1:49 ` [PATCH 1/2 roland/arm-sfi-macros] ARM: sfi_breg " Joseph S. Myers
2013-03-15 16:25 ` Roland McGrath
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