Merge branch 'work.sendmsg' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

[karo-tx-linux.git] / arch / mips / Makefile

diff --git a/arch/mips/Makefile b/arch/mips/Makefile
index 6ea306b28ae94e435c82d3c71f557754c500ebdc..8ef9c02747fa95a753ea79b77ed2a177a60ac6ad 100644 (file)
--- a/arch/mips/Makefile
+++ b/arch/mips/Makefile
@@ -131,6 +131,21 @@ cflags-$(CONFIG_CPU_LITTLE_ENDIAN) += $(shell $(CC) -dumpmachine |grep -q 'mips.
 
 cflags-$(CONFIG_SB1XXX_CORELIS)        += $(call cc-option,-mno-sched-prolog) \
                                   -fno-omit-frame-pointer
+
+# Some distribution-specific toolchains might pass the -fstack-check
+# option during the build, which adds a simple stack-probe at the beginning
+# of every function.  This stack probe is to ensure that there is enough
+# stack space, else a SEGV is generated.  This is not desirable for MIPS
+# as kernel stacks are small, placed in unmapped virtual memory, and do not
+# grow when overflowed.  Especially on SGI IP27 platforms, this check will
+# lead to a NULL pointer dereference in _raw_spin_lock_irq.
+#
+# In disassembly, this stack probe appears at the top of a function as:
+#    sd                zero,<offset>(sp)
+# Where <offset> is a negative value.
+#
+cflags-y += -fno-stack-check
+
 #
 # CPU-dependent compiler/assembler options for optimization.
 #