- 24 6月, 2021 14 次提交
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由 Thomas Gleixner 提交于
Both function names are a misnomer. fpu__save() is actually about synchronizing the hardware register state into the task's memory state so that either coredump or a math exception handler can inspect the state at the time where the problem happens. The function guarantees to preserve the register state, while "save" is a common terminology for saving the current state so it can be modified and restored later. This is clearly not the case here. Rename it to fpu_sync_fpstate(). fpu__copy() is used to clone the current task's FPU state when duplicating task_struct. While the register state is a copy the rest of the FPU state is not. Name it accordingly and remove the really pointless @src argument along with the warning which comes along with it. Nothing can ever copy the FPU state of a non-current task. It's clearly just a consequence of arch_dup_task_struct(), but it makes no sense to proliferate that further. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121455.196727450@linutronix.de
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由 Dave Hansen 提交于
write_pkru() was originally used just to write to the PKRU register. It was mercifully short and sweet and was not out of place in pgtable.h with some other pkey-related code. But, later work included a requirement to also modify the task XSAVE buffer when updating the register. This really is more related to the XSAVE architecture than to paging. Move the read/write_pkru() to asm/pkru.h. pgtable.h won't miss them. Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121455.102647114@linutronix.de
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由 Thomas Gleixner 提交于
The copy functions for the independent features are horribly named and the supervisor and independent part is just overengineered. The point is that the supplied mask has either to be a subset of the independent features or a subset of the task->fpu.xstate managed features. Rewrite it so it checks for invalid overlaps of these areas in the caller supplied feature mask. Rename it so it follows the new naming convention for these operations. Mop up the function documentation. This allows to use that function for other purposes as well. Suggested-by: NPeter Zijlstra <peterz@infradead.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Tested-by: NKan Liang <kan.liang@linux.intel.com> Link: https://lkml.kernel.org/r/20210623121455.004880675@linutronix.de
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由 Andy Lutomirski 提交于
The salient feature of "dynamic" XSTATEs is that they are not part of the main task XSTATE buffer. The fact that they are dynamically allocated is irrelevant and will become quite confusing when user math XSTATEs start being dynamically allocated. Rename them to "independent" because they are independent of the main XSTATE code. This is just a search-and-replace with some whitespace updates to keep things aligned. Signed-off-by: NAndy Lutomirski <luto@kernel.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Link: https://lore.kernel.org/r/1eecb0e4f3e07828ebe5d737ec77dc3b708fad2d.1623388344.git.luto@kernel.org Link: https://lkml.kernel.org/r/20210623121454.911450390@linutronix.de
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由 Thomas Gleixner 提交于
Again this not a copy. It's restoring register state from kernel memory. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121454.816581630@linutronix.de
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由 Thomas Gleixner 提交于
This is not a copy functionality. It restores the register state from the supplied kernel buffer. No functional changes. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121454.716058365@linutronix.de
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由 Thomas Gleixner 提交于
The FNSAVE support requires conditionals in quite some call paths because FNSAVE reinitializes the FPU hardware. If the save has to preserve the FPU register state then the caller has to conditionally restore it from memory when FNSAVE is in use. This also requires a conditional in context switch because the restore avoidance optimization cannot work with FNSAVE. As this only affects 20+ years old CPUs there is really no reason to keep this optimization effective for FNSAVE. It's about time to not optimize for antiques anymore. Just unconditionally FRSTOR the save content to the registers and clean up the conditionals all over the place. Suggested-by: NDave Hansen <dave.hansen@linux.intel.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121454.617369268@linutronix.de
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由 Thomas Gleixner 提交于
A copy is guaranteed to leave the source intact, which is not the case when FNSAVE is used as that reinitilizes the registers. Save does not make such guarantees and it matches what this is about, i.e. to save the state for a later restore. Rename it to save_fpregs_to_fpstate(). Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121454.508853062@linutronix.de
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由 Thomas Gleixner 提交于
copy_uabi_from_user_to_xstate() and copy_uabi_from_kernel_to_xstate() are almost identical except for the copy function. Unify them. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Acked-by: NAndy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20210623121454.414215896@linutronix.de
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由 Thomas Gleixner 提交于
Rename them to reflect that these functions deal with user space format XSAVE buffers. copy_kernel_to_xstate() -> copy_uabi_from_kernel_to_xstate() copy_user_to_xstate() -> copy_sigframe_from_user_to_xstate() Again a clear statement that these functions deal with user space ABI. Suggested-by: NAndy Lutomirski <luto@kernel.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121454.318485015@linutronix.de
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由 Thomas Gleixner 提交于
The function names for fnsave/fnrstor operations are horribly named and a permanent source of confusion. Rename: copy_kernel_to_fregs() to frstor() copy_fregs_to_user() to fnsave_to_user_sigframe() copy_user_to_fregs() to frstor_from_user_sigframe() so it's clear what these are doing. All these functions are really low level wrappers around the equally named instructions, so mapping to the documentation is just natural. No functional change. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121454.223594101@linutronix.de
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由 Thomas Gleixner 提交于
This is in the way of renaming the low level hardware accessors to match the instruction name. Prepend it with FPU_ which is consistent vs. the rest of the emulation code. No functional change. [ bp: Correct the Reported-by: ] Reported-by: Nkernel test robot <lkp@intel.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121454.111665161@linutronix.de
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由 Thomas Gleixner 提交于
The function names for fxsave/fxrstor operations are horribly named and a permanent source of confusion. Rename: copy_fxregs_to_kernel() to fxsave() copy_kernel_to_fxregs() to fxrstor() copy_fxregs_to_user() to fxsave_to_user_sigframe() copy_user_to_fxregs() to fxrstor_from_user_sigframe() so it's clear what these are doing. All these functions are really low level wrappers around the equally named instructions, so mapping to the documentation is just natural. While at it, replace the static_cpu_has(X86_FEATURE_FXSR) with use_fxsr() to be consistent with the rest of the code. No functional change. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121454.017863494@linutronix.de
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由 Thomas Gleixner 提交于
The function names for xsave[s]/xrstor[s] operations are horribly named and a permanent source of confusion. Rename: copy_xregs_to_user() to xsave_to_user_sigframe() copy_user_to_xregs() to xrstor_from_user_sigframe() so it's entirely clear what this is about. This is also a clear indicator of the potentially different storage format because this is user ABI and cannot use compacted format. No functional change. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121453.924266705@linutronix.de
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- 23 6月, 2021 26 次提交
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由 Thomas Gleixner 提交于
The function names for xsave[s]/xrstor[s] operations are horribly named and a permanent source of confusion. Rename: copy_xregs_to_kernel() to os_xsave() copy_kernel_to_xregs() to os_xrstor() These are truly low level wrappers around the actual instructions XSAVE[OPT]/XRSTOR and XSAVES/XRSTORS with the twist that the selection based on the available CPU features happens with an alternative to avoid conditionals all over the place and to provide the best performance for hot paths. The os_ prefix tells that this is the OS selected mechanism. No functional change. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121453.830239347@linutronix.de
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由 Thomas Gleixner 提交于
If the fast path of restoring the FPU state on sigreturn fails or is not taken and the current task's FPU is active then the FPU has to be deactivated for the slow path to allow a safe update of the tasks FPU memory state. With supervisor states enabled, this requires to save the supervisor state in the memory state first. Supervisor states require XSAVES so saving only the supervisor state requires to reshuffle the memory buffer because XSAVES uses the compacted format and therefore stores the supervisor states at the beginning of the memory state. That's just an overengineered optimization. Get rid of it and save the full state for this case. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NAndy Lutomirski <luto@kernel.org> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121453.734561971@linutronix.de
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由 Thomas Gleixner 提交于
The function does a sanity check with a WARN_ON_ONCE() but happily proceeds when the pkey argument is out of range. Clean it up. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121453.635764326@linutronix.de
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由 Dave Hansen 提交于
PKRU is being removed from the kernel XSAVE/FPU buffers. This removal will probably include warnings for code that look up PKRU in those buffers. KVM currently looks up the location of PKRU but doesn't even use the pointer that it gets back. Rework the code to avoid calling get_xsave_addr() except in cases where its result is actually used. This makes the code more clear and also avoids the inevitable PKRU warnings. This is probably a good cleanup and could go upstream idependently of any PKRU rework. Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121453.541037562@linutronix.de
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由 Thomas Gleixner 提交于
This function is pointlessly global and a complete misnomer because it's usage is related to both supervisor state checks and compacted format checks. Remove it and just make the conditions check the XSAVES feature. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121453.425493349@linutronix.de
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由 Thomas Gleixner 提交于
The only usecase for fpu__write_begin is the set() callback of regset, so the function is pointlessly global. Move it to the regset code and rename it to fpu_force_restore() which is exactly decribing what the function does. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121453.328652975@linutronix.de
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由 Thomas Gleixner 提交于
The function can only be used from the regset get() callbacks safely. So there is no reason to have it globally exposed. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121453.234942936@linutronix.de
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由 Thomas Gleixner 提交于
No more users. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121453.124819167@linutronix.de
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由 Thomas Gleixner 提交于
Use the new functionality of copy_xstate_to_uabi_buf() to retrieve the FX state when XSAVE* is in use. This avoids to overwrite the FPU state buffer with fpstate_sanitize_xstate() which is error prone and duplicated code. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121453.014441775@linutronix.de
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由 Thomas Gleixner 提交于
Use the new functionality of copy_xstate_to_uabi_buf() to retrieve the FX state when XSAVE* is in use. This avoids overwriting the FPU state buffer with fpstate_sanitize_xstate() which is error prone and duplicated code. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121452.901736860@linutronix.de
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由 Thomas Gleixner 提交于
When xsave with init state optimization is used then a component's state in the task's xsave buffer can be stale when the corresponding feature bit is not set. fpregs_get() and xfpregs_get() invoke fpstate_sanitize_xstate() to update the task's xsave buffer before retrieving the FX or FP state. That's just duplicated code as copy_xstate_to_kernel() already handles this correctly. Add a copy mode argument to the function which allows to restrict the state copy to the FP and SSE features. Also rename the function to copy_xstate_to_uabi_buf() so the name reflects what it is doing. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121452.805327286@linutronix.de
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由 Andy Lutomirski 提交于
fpregs_set() has unnecessary complexity to support short or nonzero-offset writes and to handle the case in which a copy from userspace overwrites some of the target buffer and then fails. Support for partial writes is useless -- just require that the write has offset 0 and the correct size, and copy into a temporary kernel buffer to avoid clobbering the state if the user access fails. Signed-off-by: NAndy Lutomirski <luto@kernel.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121452.710467587@linutronix.de
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由 Andy Lutomirski 提交于
There is no benefit from accepting and silently changing an invalid MXCSR value supplied via ptrace(). Instead, return -EINVAL on invalid input. Signed-off-by: NAndy Lutomirski <luto@kernel.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121452.613614842@linutronix.de
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由 Andy Lutomirski 提交于
xfpregs_set() was incomprehensible. Almost all of the complexity was due to trying to support nonsensically sized writes or -EFAULT errors that would have partially or completely overwritten the destination before failing. Nonsensically sized input would only have been possible using PTRACE_SETREGSET on REGSET_XFP. Fortunately, it appears (based on Debian code search results) that no one uses that API at all, let alone with the wrong sized buffer. Failed user access can be handled more cleanly by first copying to kernel memory. Just rewrite it to require sensible input. Signed-off-by: NAndy Lutomirski <luto@kernel.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121452.504234607@linutronix.de
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由 Dave Hansen 提交于
ptrace() has interfaces that let a ptracer inspect a ptracee's register state. This includes XSAVE state. The ptrace() ABI includes a hardware-format XSAVE buffer for both the SETREGS and GETREGS interfaces. In the old days, the kernel buffer and the ptrace() ABI buffer were the same boring non-compacted format. But, since the advent of supervisor states and the compacted format, the kernel buffer has diverged from the format presented in the ABI. This leads to two paths in the kernel: 1. Effectively a verbatim copy_to_user() which just copies the kernel buffer out to userspace. This is used when the kernel buffer is kept in the non-compacted form which means that it shares a format with the ptrace ABI. 2. A one-state-at-a-time path: copy_xstate_to_kernel(). This is theoretically slower since it does a bunch of piecemeal copies. Remove the verbatim copy case. Speed probably does not matter in this path, and the vast majority of new hardware will use the one-state-at-a-time path anyway. This ensures greater testing for the "slow" path. This also makes enabling PKRU in this interface easier since a single path can be patched instead of two. Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NAndy Lutomirski <luto@kernel.org> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121452.408457100@linutronix.de
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由 Thomas Gleixner 提交于
Instead of masking out reserved bits, check them and reject the provided state as invalid if not zero. Suggested-by: NAndy Lutomirski <luto@kernel.org> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121452.308388343@linutronix.de
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由 Thomas Gleixner 提交于
xstateregs_set() operates on a stopped task and tries to copy the provided buffer into the task's fpu.state.xsave buffer. Any error while copying or invalid state detected after copying results in wiping the target task's FPU state completely including supervisor states. That's just wrong. The caller supplied invalid data or has a problem with unmapped memory, so there is absolutely no justification to corrupt the target state. Fix this with the following modifications: 1) If data has to be copied from userspace, allocate a buffer and copy from user first. 2) Use copy_kernel_to_xstate() unconditionally so that header checking works correctly. 3) Return on error without corrupting the target state. This prevents corrupting states and lets the caller deal with the problem it caused in the first place. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121452.214903673@linutronix.de
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由 Thomas Gleixner 提交于
If the count argument is larger than the xstate size, this will happily copy beyond the end of xstate. Fixes: 91c3dba7 ("x86/fpu/xstate: Fix PTRACE frames for XSAVES") Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NAndy Lutomirski <luto@kernel.org> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121452.120741557@linutronix.de
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由 Thomas Gleixner 提交于
They are only used in fpstate_init() and there is no point to have them in a header just to make reading the code harder. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121452.023118522@linutronix.de
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由 Thomas Gleixner 提交于
Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NAndy Lutomirski <luto@kernel.org> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121451.915614415@linutronix.de
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由 Thomas Gleixner 提交于
This function is really not doing what the comment advertises: "Find supported xfeatures based on cpu features and command-line input. This must be called after fpu__init_parse_early_param() is called and xfeatures_mask is enumerated." fpu__init_parse_early_param() does not exist anymore and the function just returns a constant. Remove it and fix the caller and get rid of further references to fpu__init_parse_early_param(). Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121451.816404717@linutronix.de
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由 Thomas Gleixner 提交于
Nothing has to modify this after init. But of course there is code which unconditionally masks xfeatures_mask_all on CPU hotplug. This goes unnoticed during boot hotplug because at that point the variable is still RW mapped. This is broken in several ways: 1) Masking this in post init CPU hotplug means that any modification of this state goes unnoticed until actual hotplug happens. 2) If that ever happens then these bogus feature bits are already populated all over the place and the system is in inconsistent state vs. the compacted XSTATE offsets. If at all then this has to panic the machine because the inconsistency cannot be undone anymore. Make this a one-time paranoia check in xstate init code and disable xsave when this happens. Reported-by: NKan Liang <kan.liang@linux.intel.com> Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121451.712803952@linutronix.de
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由 Thomas Gleixner 提交于
Nothing modifies these after booting. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NAndy Lutomirski <luto@kernel.org> Link: https://lkml.kernel.org/r/20210623121451.611751529@linutronix.de
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由 Thomas Gleixner 提交于
This cannot work and it's unclear how that ever made a difference. init_fpstate.xsave.header.xfeatures is always 0 so get_xsave_addr() will always return a NULL pointer, which will prevent storing the default PKRU value in init_fpstate. Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121451.451391598@linutronix.de
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由 Thomas Gleixner 提交于
The gap handling in copy_xstate_to_kernel() is wrong when XSAVES is in use. Using init_fpstate for copying the init state of features which are not set in the xstate header is only correct for the legacy area, but not for the extended features area because when XSAVES is in use then init_fpstate is in compacted form which means the xstate offsets which are used to copy from init_fpstate are not valid. Fortunately, this is not a real problem today because all extended features in use have an all-zeros init state, but it is wrong nevertheless and with a potentially dynamically sized init_fpstate this would result in an access outside of the init_fpstate. Fix this by keeping track of the last copied state in the target buffer and explicitly zero it when there is a feature or alignment gap. Use the compacted offset when accessing the extended feature space in init_fpstate. As this is not a functional issue on older kernels this is intentionally not tagged for stable. Fixes: b8be15d5 ("x86/fpu/xstate: Re-enable XSAVES") Signed-off-by: NThomas Gleixner <tglx@linutronix.de> Signed-off-by: NBorislav Petkov <bp@suse.de> Reviewed-by: NBorislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20210623121451.294282032@linutronix.de
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由 Borislav Petkov 提交于
Pick up dependent changes which either went mainline (x86/urgent is based on -rc7 and that contains them) as urgent fixes and the current x86/urgent branch which contains two more urgent fixes, so that the bigger FPU rework can base off ontop. Signed-off-by: NBorislav Petkov <bp@suse.de>
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