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| author | Chang S. Bae <chang.seok.bae@intel.com> | 2022-08-24 12:12:22 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2022-10-17 15:44:25 +0200 |
| commit | d3e021adac7c51a26d9ede167c789fcc1b878467 (patch) | |
| tree | a7b1daf0dbda70611987f3a4a0de7ddf9353ef68 /arch/x86 | |
| parent | c32d7cab57e3a77af8ecc17cde7a5761a26483b8 (diff) | |
| download | linux-d3e021adac7c51a26d9ede167c789fcc1b878467.tar.bz2 | |
x86/fpu: Fix the init_fpstate size check with the actual size
The init_fpstate buffer is statically allocated. Thus, the sanity test was
established to check whether the pre-allocated buffer is enough for the
calculated size or not.
The currently measured size is not strictly relevant. Fix to validate the
calculated init_fpstate size with the pre-allocated area.
Also, replace the sanity check function with open code for clarity. The
abstraction itself and the function naming do not tend to represent simply
what it does.
Fixes: 2ae996e0c1a3 ("x86/fpu: Calculate the default sizes independently")
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20220824191223.1248-3-chang.seok.bae@intel.com
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/fpu/xstate.c | 24 |
1 files changed, 6 insertions, 18 deletions
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index f0ce10620ab0..f5ef78633b4c 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -678,20 +678,6 @@ static unsigned int __init get_xsave_size_user(void) return ebx; } -/* - * Will the runtime-enumerated 'xstate_size' fit in the init - * task's statically-allocated buffer? - */ -static bool __init is_supported_xstate_size(unsigned int test_xstate_size) -{ - if (test_xstate_size <= sizeof(init_fpstate.regs)) - return true; - - pr_warn("x86/fpu: xstate buffer too small (%zu < %d), disabling xsave\n", - sizeof(init_fpstate.regs), test_xstate_size); - return false; -} - static int __init init_xstate_size(void) { /* Recompute the context size for enabled features: */ @@ -717,10 +703,6 @@ static int __init init_xstate_size(void) kernel_default_size = xstate_calculate_size(fpu_kernel_cfg.default_features, compacted); - /* Ensure we have the space to store all default enabled features. */ - if (!is_supported_xstate_size(kernel_default_size)) - return -EINVAL; - if (!paranoid_xstate_size_valid(kernel_size)) return -EINVAL; @@ -879,6 +861,12 @@ void __init fpu__init_system_xstate(unsigned int legacy_size) init_fpstate.size = fpu_kernel_cfg.max_size; init_fpstate.xfeatures = fpu_kernel_cfg.max_features; + if (init_fpstate.size > sizeof(init_fpstate.regs)) { + pr_warn("x86/fpu: init_fpstate buffer too small (%zu < %d), disabling XSAVE\n", + sizeof(init_fpstate.regs), init_fpstate.size); + goto out_disable; + } + setup_init_fpu_buf(); /* |