[PATCH 1/3] x86/fpu: Configure init_fpstate attributes orderly

From: Chang S. Bae
Date: Wed Aug 24 2022 - 15:22:14 EST


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>
Cc: x86@xxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
---
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 621f4b6cac4a..8946f89761cc 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 c8340156bfd2..f0ce10620ab0 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();

/*
--
2.17.1