svn commit: r279949 - in head: lib/libstand sys/boot/amd64 sys/boot/efi/libefi sys/boot/ficl

[John Baldwin]

Author: jhb
Date: Fri Mar 13 09:38:16 2015
New Revision: 279949
URL: https://svnweb.freebsd.org/changeset/base/279949

Log:
  The System V ABI for amd64 allows functions to use space in a 128 byte
  redzone below the stack pointer for scratch space and requires
  interrupt and signal frames to avoid overwriting it. However, EFI uses
  the Windows ABI which does not support this. As a result, interrupt
  handlers in EFI push their interrupt frames directly on top of the
  stack pointer. If the compiler used the red zone in a function in the
  EFI loader, then a device interrupt that occurred while that function
  was running could trash its local variables.  In practice this happens
  fairly reliable when using gzipfs as an interrupt during decompression
  can trash the local variables in the inflate_table() function
  resulting in corrupted output or hangs.
  
  Fix this by disabling the redzone for amd64 EFI binaries. This
  requires building not only the loader but any libraries used by the
  loader without redzone support.
  
  Thanks to Jilles for pointing me at the redzone once I found the stack
  corruption.
  
  Differential Revision:	https://reviews.freebsd.org/D2054
  Reviewed by:	imp
  MFC after:	2 weeks
  Sponsored by:	Cisco Systems, Inc.

Modified:
  head/lib/libstand/Makefile
  head/sys/boot/amd64/Makefile.inc
  head/sys/boot/efi/libefi/Makefile
  head/sys/boot/ficl/Makefile

Modified: head/lib/libstand/Makefile
==============================================================================
--- head/lib/libstand/Makefile	Fri Mar 13 09:03:25 2015	(r279948)
+++ head/lib/libstand/Makefile	Fri Mar 13 09:38:16 2015	(r279949)
@@ -28,7 +28,7 @@ CFLAGS+=	-mno-mmx -mno-3dnow -mno-sse -m
 CFLAGS.gcc+=	-mpreferred-stack-boundary=2
 .endif
 .if ${MACHINE_CPUARCH} == "amd64"
-CFLAGS+=	-fPIC
+CFLAGS+=	-fPIC -mno-red-zone
 .endif
 .if ${MACHINE} == "pc98"
 CFLAGS+=	-Os

Modified: head/sys/boot/amd64/Makefile.inc
==============================================================================
--- head/sys/boot/amd64/Makefile.inc	Fri Mar 13 09:03:25 2015	(r279948)
+++ head/sys/boot/amd64/Makefile.inc	Fri Mar 13 09:38:16 2015	(r279949)
@@ -5,7 +5,7 @@
 BINDIR?=	/boot
 
 # See conf/kern.mk for the correct set of these
-CFLAGS+=	-ffreestanding
+CFLAGS+=	-ffreestanding -mno-red-zone
 CFLAGS+=	-mno-mmx -mno-sse -mno-aes -mno-avx -msoft-float
 LDFLAGS+=	-nostdlib
 

Modified: head/sys/boot/efi/libefi/Makefile
==============================================================================
--- head/sys/boot/efi/libefi/Makefile	Fri Mar 13 09:03:25 2015	(r279948)
+++ head/sys/boot/efi/libefi/Makefile	Fri Mar 13 09:38:16 2015	(r279949)
@@ -9,7 +9,7 @@ SRCS=	delay.c efi_console.c efinet.c efi
 SRCS+= nullconsole.c comconsole.c
 
 .if ${MACHINE_ARCH} == "amd64"
-CFLAGS+= -fPIC
+CFLAGS+= -fPIC -mno-red-zone
 .endif
 CFLAGS+= -I${.CURDIR}/../include
 CFLAGS+= -I${.CURDIR}/../include/${MACHINE_CPUARCH}

Modified: head/sys/boot/ficl/Makefile
==============================================================================
--- head/sys/boot/ficl/Makefile	Fri Mar 13 09:03:25 2015	(r279948)
+++ head/sys/boot/ficl/Makefile	Fri Mar 13 09:38:16 2015	(r279949)
@@ -21,6 +21,9 @@ CFLAGS+=	-ffreestanding
 CFLAGS+=	-march=i386
 CFLAGS.gcc+=	-mpreferred-stack-boundary=2
 .endif
+.if ${MACHINE_CPUARCH} == "amd64"
+CFLAGS+=	-mno-red-zone
+.endif
 .if ${MACHINE_CPUARCH} == "i386" || ${MACHINE_CPUARCH} == "amd64"
 CFLAGS+=	-mno-mmx -mno-3dnow -mno-sse -mno-sse2 -mno-sse3 -msoft-float
 .endif