[tip: x86/urgent] x86/fpu: Configure init_fpstate attributes orderly

From: tip-bot2 for Chang S. Bae
Date: Mon Oct 17 2022 - 09:47:45 EST


The following commit has been merged into the x86/urgent branch of tip:

Commit-ID: c32d7cab57e3a77af8ecc17cde7a5761a26483b8
Gitweb: https://git.kernel.org/tip/c32d7cab57e3a77af8ecc17cde7a5761a26483b8
Author: Chang S. Bae <chang.seok.bae@xxxxxxxxx>
AuthorDate: Wed, 24 Aug 2022 12:12:21 -07:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Mon, 17 Oct 2022 15:44:25 +02:00

x86/fpu: Configure init_fpstate attributes orderly

The init_fpstate setup code is spread out and out of order. The init image
is recorded before its scoped features and the buffer size are determined.

Determine the scope of init_fpstate components and its size before
recording the init state. Also move the relevant code together.

Signed-off-by: Chang S. Bae <chang.seok.bae@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: neelnatu@xxxxxxxxxx
Link: https://lore.kernel.org/r/20220824191223.1248-2-chang.seok.bae@xxxxxxxxx

---
arch/x86/kernel/fpu/init.c | 8 --------
arch/x86/kernel/fpu/xstate.c | 6 +++++-
2 files changed, 5 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c
index 621f4b6..8946f89 100644
--- a/arch/x86/kernel/fpu/init.c
+++ b/arch/x86/kernel/fpu/init.c
@@ -210,13 +210,6 @@ static void __init fpu__init_system_xstate_size_legacy(void)
fpstate_reset(&current->thread.fpu);
}

-static void __init fpu__init_init_fpstate(void)
-{
- /* Bring init_fpstate size and features up to date */
- init_fpstate.size = fpu_kernel_cfg.max_size;
- init_fpstate.xfeatures = fpu_kernel_cfg.max_features;
-}
-
/*
* Called on the boot CPU once per system bootup, to set up the initial
* FPU state that is later cloned into all processes:
@@ -236,5 +229,4 @@ void __init fpu__init_system(struct cpuinfo_x86 *c)
fpu__init_system_xstate_size_legacy();
fpu__init_system_xstate(fpu_kernel_cfg.max_size);
fpu__init_task_struct_size();
- fpu__init_init_fpstate();
}
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index c834015..f0ce106 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -360,7 +360,7 @@ static void __init setup_init_fpu_buf(void)

print_xstate_features();

- xstate_init_xcomp_bv(&init_fpstate.regs.xsave, fpu_kernel_cfg.max_features);
+ xstate_init_xcomp_bv(&init_fpstate.regs.xsave, init_fpstate.xfeatures);

/*
* Init all the features state with header.xfeatures being 0x0
@@ -875,6 +875,10 @@ void __init fpu__init_system_xstate(unsigned int legacy_size)
update_regset_xstate_info(fpu_user_cfg.max_size,
fpu_user_cfg.max_features);

+ /* Bring init_fpstate size and features up to date */
+ init_fpstate.size = fpu_kernel_cfg.max_size;
+ init_fpstate.xfeatures = fpu_kernel_cfg.max_features;
+
setup_init_fpu_buf();

/*