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authorDavid S. Miller <davem@davemloft.net>2015-07-23 00:41:16 -0700
committerDavid S. Miller <davem@davemloft.net>2015-07-23 00:41:16 -0700
commitc5e40ee287db61a79af1746954ee03ebbf1ff8a3 (patch)
tree007da00e75e9b84766ac4868421705300e1e2e14 /arch/x86/kernel/fpu/init.c
parentip_tunnel: Provide tunnel metadata API for CONFIG_INET=n (diff)
parentMerge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net (diff)
downloadlinux-dev-c5e40ee287db61a79af1746954ee03ebbf1ff8a3.tar.xz
linux-dev-c5e40ee287db61a79af1746954ee03ebbf1ff8a3.zip
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Conflicts: net/bridge/br_mdb.c br_mdb.c conflict was a function call being removed to fix a bug in 'net' but whose signature was changed in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/x86/kernel/fpu/init.c')
-rw-r--r--arch/x86/kernel/fpu/init.c40
1 files changed, 40 insertions, 0 deletions
diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c
index 32826791e675..0b39173dd971 100644
--- a/arch/x86/kernel/fpu/init.c
+++ b/arch/x86/kernel/fpu/init.c
@@ -4,6 +4,8 @@
#include <asm/fpu/internal.h>
#include <asm/tlbflush.h>
+#include <linux/sched.h>
+
/*
* Initialize the TS bit in CR0 according to the style of context-switches
* we are using:
@@ -136,6 +138,43 @@ static void __init fpu__init_system_generic(void)
unsigned int xstate_size;
EXPORT_SYMBOL_GPL(xstate_size);
+/* Enforce that 'MEMBER' is the last field of 'TYPE': */
+#define CHECK_MEMBER_AT_END_OF(TYPE, MEMBER) \
+ BUILD_BUG_ON(sizeof(TYPE) != offsetofend(TYPE, MEMBER))
+
+/*
+ * We append the 'struct fpu' to the task_struct:
+ */
+static void __init fpu__init_task_struct_size(void)
+{
+ int task_size = sizeof(struct task_struct);
+
+ /*
+ * Subtract off the static size of the register state.
+ * It potentially has a bunch of padding.
+ */
+ task_size -= sizeof(((struct task_struct *)0)->thread.fpu.state);
+
+ /*
+ * Add back the dynamically-calculated register state
+ * size.
+ */
+ task_size += xstate_size;
+
+ /*
+ * We dynamically size 'struct fpu', so we require that
+ * it be at the end of 'thread_struct' and that
+ * 'thread_struct' be at the end of 'task_struct'. If
+ * you hit a compile error here, check the structure to
+ * see if something got added to the end.
+ */
+ CHECK_MEMBER_AT_END_OF(struct fpu, state);
+ CHECK_MEMBER_AT_END_OF(struct thread_struct, fpu);
+ CHECK_MEMBER_AT_END_OF(struct task_struct, thread);
+
+ arch_task_struct_size = task_size;
+}
+
/*
* Set up the xstate_size based on the legacy FPU context size.
*
@@ -287,6 +326,7 @@ void __init fpu__init_system(struct cpuinfo_x86 *c)
fpu__init_system_generic();
fpu__init_system_xstate_size_legacy();
fpu__init_system_xstate();
+ fpu__init_task_struct_size();
fpu__init_system_ctx_switch();
}