* [PATCH 0/2] x86/fpu: minor cleanups [not found] ` <20150302174818.GA16886@redhat.com> @ 2015-03-02 18:32 ` Oleg Nesterov 2015-03-02 18:32 ` [PATCH 1/2] x86/regsets: change xstateregs_get/set to use ->xsave.i387 rather than ->fxsave Oleg Nesterov 2015-03-02 18:32 ` [PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths Oleg Nesterov 0 siblings, 2 replies; 12+ messages in thread From: Oleg Nesterov @ 2015-03-02 18:32 UTC (permalink / raw) To: Tavis Ormandy, Borislav Petkov, Ingo Molnar Cc: Rik van Riel, Andy Lutomirski, Linus Torvalds, linux-kernel add lkml/cc's. On 03/02, Oleg Nesterov wrote: > > Btw, why xstateregs_get/set() looks so confusing? The comment says > "Copy the 48bytes defined by the software first into the xstate" but the > code uses ->fxsave. Yes, this is the same memory, but still. I'll send > the cosmetic cleanup. > > Or fx_finit()... Again, memset(fx, 0, xstate_size) is correct but only > because of the current layout. I think this needs a cleanup too. Of course this is purely cosmetic, but still... Oleg. ^ permalink raw reply [flat|nested] 12+ messages in thread
* [PATCH 1/2] x86/regsets: change xstateregs_get/set to use ->xsave.i387 rather than ->fxsave 2015-03-02 18:32 ` [PATCH 0/2] x86/fpu: minor cleanups Oleg Nesterov @ 2015-03-02 18:32 ` Oleg Nesterov 2015-03-03 19:23 ` Rik van Riel ` (2 more replies) 2015-03-02 18:32 ` [PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths Oleg Nesterov 1 sibling, 3 replies; 12+ messages in thread From: Oleg Nesterov @ 2015-03-02 18:32 UTC (permalink / raw) To: Tavis Ormandy, Borislav Petkov, Ingo Molnar Cc: Rik van Riel, Andy Lutomirski, Linus Torvalds, linux-kernel Cosmetic. xstateregs_get() and xstateregs_set() abuse ->fxsave to access xsave->i387.sw_reserved. This is correct, ->fxsave and xsave->i387 share the same memory, but imho this looks confusing. And we can make this code more readable if we add "struct xsave_struct *" local. Signed-off-by: Oleg Nesterov <oleg@redhat.com> --- arch/x86/kernel/i387.c | 25 +++++++++---------------- 1 files changed, 9 insertions(+), 16 deletions(-) diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index 8e070a6..4b12df8 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -339,6 +339,7 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf) { + struct xsave_struct *xsave = &target->thread.fpu.state->xsave; int ret; if (!cpu_has_xsave) @@ -353,14 +354,12 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset, * memory layout in the thread struct, so that we can copy the entire * xstateregs to the user using one user_regset_copyout(). */ - memcpy(&target->thread.fpu.state->fxsave.sw_reserved, - xstate_fx_sw_bytes, sizeof(xstate_fx_sw_bytes)); - + memcpy(&xsave->i387.sw_reserved, + xstate_fx_sw_bytes, sizeof(xstate_fx_sw_bytes)); /* * Copy the xstate memory layout. */ - ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, - &target->thread.fpu.state->xsave, 0, -1); + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, xsave, 0, -1); return ret; } @@ -368,8 +367,8 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, const void *kbuf, const void __user *ubuf) { + struct xsave_struct *xsave = &target->thread.fpu.state->xsave; int ret; - struct xsave_hdr_struct *xsave_hdr; if (!cpu_has_xsave) return -ENODEV; @@ -378,22 +377,16 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset, if (ret) return ret; - ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, - &target->thread.fpu.state->xsave, 0, -1); - + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, xsave, 0, -1); /* * mxcsr reserved bits must be masked to zero for security reasons. */ - target->thread.fpu.state->fxsave.mxcsr &= mxcsr_feature_mask; - - xsave_hdr = &target->thread.fpu.state->xsave.xsave_hdr; - - xsave_hdr->xstate_bv &= pcntxt_mask; + xsave->i387.mxcsr &= mxcsr_feature_mask; + xsave->xsave_hdr.xstate_bv &= pcntxt_mask; /* * These bits must be zero. */ - memset(xsave_hdr->reserved, 0, 48); - + memset(&xsave->xsave_hdr.reserved, 0, 48); return ret; } -- 1.5.5.1 ^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH 1/2] x86/regsets: change xstateregs_get/set to use ->xsave.i387 rather than ->fxsave 2015-03-02 18:32 ` [PATCH 1/2] x86/regsets: change xstateregs_get/set to use ->xsave.i387 rather than ->fxsave Oleg Nesterov @ 2015-03-03 19:23 ` Rik van Riel 2015-03-04 10:30 ` Borislav Petkov 2015-03-10 10:08 ` [tip:x86/fpu] x86/fpu: Change xstateregs_get()/set() to use -> xsave.i387 " tip-bot for Oleg Nesterov 2 siblings, 0 replies; 12+ messages in thread From: Rik van Riel @ 2015-03-03 19:23 UTC (permalink / raw) To: Oleg Nesterov, Tavis Ormandy, Borislav Petkov, Ingo Molnar Cc: Andy Lutomirski, Linus Torvalds, linux-kernel On 03/02/2015 01:32 PM, Oleg Nesterov wrote: > Cosmetic. xstateregs_get() and xstateregs_set() abuse ->fxsave to access > xsave->i387.sw_reserved. This is correct, ->fxsave and xsave->i387 share > the same memory, but imho this looks confusing. > > And we can make this code more readable if we add "struct xsave_struct *" > local. > > Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Rik van Riel <riel@redhat.com> -- All rights reversed ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 1/2] x86/regsets: change xstateregs_get/set to use ->xsave.i387 rather than ->fxsave 2015-03-02 18:32 ` [PATCH 1/2] x86/regsets: change xstateregs_get/set to use ->xsave.i387 rather than ->fxsave Oleg Nesterov 2015-03-03 19:23 ` Rik van Riel @ 2015-03-04 10:30 ` Borislav Petkov 2015-03-10 10:08 ` [tip:x86/fpu] x86/fpu: Change xstateregs_get()/set() to use -> xsave.i387 " tip-bot for Oleg Nesterov 2 siblings, 0 replies; 12+ messages in thread From: Borislav Petkov @ 2015-03-04 10:30 UTC (permalink / raw) To: Oleg Nesterov Cc: Tavis Ormandy, Ingo Molnar, Rik van Riel, Andy Lutomirski, Linus Torvalds, linux-kernel On Mon, Mar 02, 2015 at 07:32:37PM +0100, Oleg Nesterov wrote: > Cosmetic. xstateregs_get() and xstateregs_set() abuse ->fxsave to access > xsave->i387.sw_reserved. This is correct, ->fxsave and xsave->i387 share > the same memory, but imho this looks confusing. > > And we can make this code more readable if we add "struct xsave_struct *" > local. > > Signed-off-by: Oleg Nesterov <oleg@redhat.com> Applied, thanks. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. -- ^ permalink raw reply [flat|nested] 12+ messages in thread
* [tip:x86/fpu] x86/fpu: Change xstateregs_get()/set() to use -> xsave.i387 rather than ->fxsave 2015-03-02 18:32 ` [PATCH 1/2] x86/regsets: change xstateregs_get/set to use ->xsave.i387 rather than ->fxsave Oleg Nesterov 2015-03-03 19:23 ` Rik van Riel 2015-03-04 10:30 ` Borislav Petkov @ 2015-03-10 10:08 ` tip-bot for Oleg Nesterov 2 siblings, 0 replies; 12+ messages in thread From: tip-bot for Oleg Nesterov @ 2015-03-10 10:08 UTC (permalink / raw) To: linux-tip-commits Cc: luto, riel, oleg, bp, hpa, taviso, linux-kernel, mingo, bp, torvalds, tglx Commit-ID: e7f180dcd8ab48f18b20d7e8a7e9b39192bdf8e0 Gitweb: http://git.kernel.org/tip/e7f180dcd8ab48f18b20d7e8a7e9b39192bdf8e0 Author: Oleg Nesterov <oleg@redhat.com> AuthorDate: Tue, 10 Mar 2015 07:06:24 +0100 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Tue, 10 Mar 2015 07:14:31 +0100 x86/fpu: Change xstateregs_get()/set() to use ->xsave.i387 rather than ->fxsave This is a cosmetic change: xstateregs_get() and xstateregs_set() abuse ->fxsave to access xsave->i387.sw_reserved. This practice is correct, ->fxsave and xsave->i387 share the same memory, but IMHO this looks confusing. And we can make this code more readable if we add a "struct xsave_struct *" local variable as well. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Tavis Ormandy <taviso@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1425967585-4725-1-git-send-email-bp@alien8.de Link: http://lkml.kernel.org/r/20150302183237.GB23085@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/kernel/i387.c | 25 +++++++++---------------- 1 file changed, 9 insertions(+), 16 deletions(-) diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index 8416b5f..03cc0ad 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -339,6 +339,7 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf) { + struct xsave_struct *xsave = &target->thread.fpu.state->xsave; int ret; if (!cpu_has_xsave) @@ -353,14 +354,12 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset, * memory layout in the thread struct, so that we can copy the entire * xstateregs to the user using one user_regset_copyout(). */ - memcpy(&target->thread.fpu.state->fxsave.sw_reserved, - xstate_fx_sw_bytes, sizeof(xstate_fx_sw_bytes)); - + memcpy(&xsave->i387.sw_reserved, + xstate_fx_sw_bytes, sizeof(xstate_fx_sw_bytes)); /* * Copy the xstate memory layout. */ - ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, - &target->thread.fpu.state->xsave, 0, -1); + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, xsave, 0, -1); return ret; } @@ -368,8 +367,8 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, const void *kbuf, const void __user *ubuf) { + struct xsave_struct *xsave = &target->thread.fpu.state->xsave; int ret; - struct xsave_hdr_struct *xsave_hdr; if (!cpu_has_xsave) return -ENODEV; @@ -378,22 +377,16 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset, if (ret) return ret; - ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, - &target->thread.fpu.state->xsave, 0, -1); - + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, xsave, 0, -1); /* * mxcsr reserved bits must be masked to zero for security reasons. */ - target->thread.fpu.state->fxsave.mxcsr &= mxcsr_feature_mask; - - xsave_hdr = &target->thread.fpu.state->xsave.xsave_hdr; - - xsave_hdr->xstate_bv &= pcntxt_mask; + xsave->i387.mxcsr &= mxcsr_feature_mask; + xsave->xsave_hdr.xstate_bv &= pcntxt_mask; /* * These bits must be zero. */ - memset(xsave_hdr->reserved, 0, 48); - + memset(&xsave->xsave_hdr.reserved, 0, 48); return ret; } ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths 2015-03-02 18:32 ` [PATCH 0/2] x86/fpu: minor cleanups Oleg Nesterov 2015-03-02 18:32 ` [PATCH 1/2] x86/regsets: change xstateregs_get/set to use ->xsave.i387 rather than ->fxsave Oleg Nesterov @ 2015-03-02 18:32 ` Oleg Nesterov 2015-03-03 22:01 ` Rik van Riel ` (2 more replies) 1 sibling, 3 replies; 12+ messages in thread From: Oleg Nesterov @ 2015-03-02 18:32 UTC (permalink / raw) To: Tavis Ormandy, Borislav Petkov, Ingo Molnar Cc: Rik van Riel, Andy Lutomirski, Linus Torvalds, linux-kernel fx_finit() has 2 users but only fpu_finit() needs to nullify xstate, alloc_bootmem_align() in setup_init_fpu_buf() returns zero-filled memory. And note that both memset()'s look confusing. Yes, offsetof() is 0 for ->fxsave or ->fsave, but it would be more clean to turn them into a single memset() which nullifies fpu->state. Signed-off-by: Oleg Nesterov <oleg@redhat.com> --- arch/x86/include/asm/fpu-internal.h | 1 - arch/x86/kernel/i387.c | 3 ++- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h index 02f2e08..8809b5a 100644 --- a/arch/x86/include/asm/fpu-internal.h +++ b/arch/x86/include/asm/fpu-internal.h @@ -107,7 +107,6 @@ static __always_inline __pure bool use_fxsr(void) static inline void fx_finit(struct i387_fxsave_struct *fx) { - memset(fx, 0, xstate_size); fx->cwd = 0x37f; fx->mxcsr = MXCSR_DEFAULT; } diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index 4b12df8..9b7759f 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -224,11 +224,12 @@ void fpu_finit(struct fpu *fpu) return; } + memset(fpu->state, 0, xstate_size); + if (cpu_has_fxsr) { fx_finit(&fpu->state->fxsave); } else { struct i387_fsave_struct *fp = &fpu->state->fsave; - memset(fp, 0, xstate_size); fp->cwd = 0xffff037fu; fp->swd = 0xffff0000u; fp->twd = 0xffffffffu; -- 1.5.5.1 ^ permalink raw reply related [flat|nested] 12+ messages in thread
* Re: [PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths 2015-03-02 18:32 ` [PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths Oleg Nesterov @ 2015-03-03 22:01 ` Rik van Riel 2015-03-04 11:38 ` Borislav Petkov 2015-03-10 10:08 ` [tip:x86/fpu] x86/fpu: Factor out memset(xstate, 0) in fpu_finit( ) paths tip-bot for Oleg Nesterov 2 siblings, 0 replies; 12+ messages in thread From: Rik van Riel @ 2015-03-03 22:01 UTC (permalink / raw) To: Oleg Nesterov, Tavis Ormandy, Borislav Petkov, Ingo Molnar Cc: Andy Lutomirski, Linus Torvalds, linux-kernel On 03/02/2015 01:32 PM, Oleg Nesterov wrote: > fx_finit() has 2 users but only fpu_finit() needs to nullify xstate, > alloc_bootmem_align() in setup_init_fpu_buf() returns zero-filled > memory. > > And note that both memset()'s look confusing. Yes, offsetof() is 0 > for ->fxsave or ->fsave, but it would be more clean to turn them into > a single memset() which nullifies fpu->state. > > Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> -- All rights reversed ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths 2015-03-02 18:32 ` [PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths Oleg Nesterov 2015-03-03 22:01 ` Rik van Riel @ 2015-03-04 11:38 ` Borislav Petkov 2015-03-10 10:08 ` [tip:x86/fpu] x86/fpu: Factor out memset(xstate, 0) in fpu_finit( ) paths tip-bot for Oleg Nesterov 2 siblings, 0 replies; 12+ messages in thread From: Borislav Petkov @ 2015-03-04 11:38 UTC (permalink / raw) To: Oleg Nesterov Cc: Tavis Ormandy, Ingo Molnar, Rik van Riel, Andy Lutomirski, Linus Torvalds, linux-kernel On Mon, Mar 02, 2015 at 07:32:57PM +0100, Oleg Nesterov wrote: > fx_finit() has 2 users but only fpu_finit() needs to nullify xstate, > alloc_bootmem_align() in setup_init_fpu_buf() returns zero-filled > memory. > > And note that both memset()'s look confusing. Yes, offsetof() is 0 > for ->fxsave or ->fsave, but it would be more clean to turn them into > a single memset() which nullifies fpu->state. > > Signed-off-by: Oleg Nesterov <oleg@redhat.com> Applied, thanks. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. -- ^ permalink raw reply [flat|nested] 12+ messages in thread
* [tip:x86/fpu] x86/fpu: Factor out memset(xstate, 0) in fpu_finit( ) paths 2015-03-02 18:32 ` [PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths Oleg Nesterov 2015-03-03 22:01 ` Rik van Riel 2015-03-04 11:38 ` Borislav Petkov @ 2015-03-10 10:08 ` tip-bot for Oleg Nesterov 2 siblings, 0 replies; 12+ messages in thread From: tip-bot for Oleg Nesterov @ 2015-03-10 10:08 UTC (permalink / raw) To: linux-tip-commits Cc: torvalds, linux-kernel, tglx, luto, bp, bp, taviso, oleg, hpa, mingo, riel Commit-ID: 1d23c4518b1f3a03c278f23333149245c178d2a6 Gitweb: http://git.kernel.org/tip/1d23c4518b1f3a03c278f23333149245c178d2a6 Author: Oleg Nesterov <oleg@redhat.com> AuthorDate: Tue, 10 Mar 2015 07:06:25 +0100 Committer: Ingo Molnar <mingo@kernel.org> CommitDate: Tue, 10 Mar 2015 07:14:31 +0100 x86/fpu: Factor out memset(xstate, 0) in fpu_finit() paths fx_finit() has two users but only fpu_finit() needs to clear xstate, alloc_bootmem_align() in setup_init_fpu_buf() returns zero-filled memory. And note that both memset()'s look confusing. Yes, offsetof() is 0 for ->fxsave or ->fsave, but it would be cleaner to turn them into a single memset() which zeroes fpu->state. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Tavis Ormandy <taviso@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1425967585-4725-2-git-send-email-bp@alien8.de Link: http://lkml.kernel.org/r/20150302183257.GC23085@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org> --- arch/x86/include/asm/fpu-internal.h | 1 - arch/x86/kernel/i387.c | 3 ++- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h index 61609b9..5fa1be2 100644 --- a/arch/x86/include/asm/fpu-internal.h +++ b/arch/x86/include/asm/fpu-internal.h @@ -135,7 +135,6 @@ static __always_inline __pure bool use_fxsr(void) static inline void fx_finit(struct i387_fxsave_struct *fx) { - memset(fx, 0, xstate_size); fx->cwd = 0x37f; fx->mxcsr = MXCSR_DEFAULT; } diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index 03cc0ad..0f3de66 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -224,11 +224,12 @@ void fpu_finit(struct fpu *fpu) return; } + memset(fpu->state, 0, xstate_size); + if (cpu_has_fxsr) { fx_finit(&fpu->state->fxsave); } else { struct i387_fsave_struct *fp = &fpu->state->fsave; - memset(fp, 0, xstate_size); fp->cwd = 0xffff037fu; fp->swd = 0xffff0000u; fp->twd = 0xffffffffu; ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [GIT PULL] x86/fpu cleanups
@ 2015-03-09 18:08 Borislav Petkov
2015-03-10 6:06 ` [PATCH 1/2] x86/fpu: Change xstateregs_get()/set() to use ->xsave.i387 rather than ->fxsave Borislav Petkov
0 siblings, 1 reply; 12+ messages in thread
From: Borislav Petkov @ 2015-03-09 18:08 UTC (permalink / raw)
To: Ingo Molnar; +Cc: Oleg Nesterov, x86-ml, lkml
Hi Ingo,
please pull two more cleanups to the FPU insanity from Oleg.
So this is *not* the urgent stuff - the urgent stuff will come later.
This is the unload-some-more-onto-tip stuff which can be safely queued
for 4.1 and I can forget about it here. :)
Thanks.
---
The following changes since commit ae486033b980346eb6a77240101210cb66924a91:
Merge tag 'tip_x86_fpu' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp into x86/fpu (2015-03-03 12:12:15 +0100)
are available in the git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp.git tags/tip_x86_fpu_2
for you to fetch changes up to 9ed010d31f173be786f0398a64f08bb4a0300c3b:
x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths (2015-03-04 11:57:46 +0100)
----------------------------------------------------------------
Two more cleanups from Oleg.
----------------------------------------------------------------
Oleg Nesterov (2):
x86/fpu: Change xstateregs_get()/set() to use ->xsave.i387 rather than ->fxsave
x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths
arch/x86/include/asm/fpu-internal.h | 1 -
arch/x86/kernel/i387.c | 28 +++++++++++-----------------
2 files changed, 11 insertions(+), 18 deletions(-)
--
Regards/Gruss,
Boris.
ECO tip #101: Trim your mails when you reply.
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^ permalink raw reply [flat|nested] 12+ messages in thread* [PATCH 1/2] x86/fpu: Change xstateregs_get()/set() to use ->xsave.i387 rather than ->fxsave 2015-03-09 18:08 [GIT PULL] x86/fpu cleanups Borislav Petkov @ 2015-03-10 6:06 ` Borislav Petkov 2015-03-10 6:06 ` [PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths Borislav Petkov 0 siblings, 1 reply; 12+ messages in thread From: Borislav Petkov @ 2015-03-10 6:06 UTC (permalink / raw) To: Ingo Molnar; +Cc: X86 ML, LKML From: Oleg Nesterov <oleg@redhat.com> This is a cosmetic change: xstateregs_get() and xstateregs_set() abuse ->fxsave to access xsave->i387.sw_reserved. This is correct, ->fxsave and xsave->i387 share the same memory, but IMHO this looks confusing. And we can make this code more readable if we add "struct xsave_struct *" local. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Tavis Ormandy <taviso@google.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: <x86@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20150302183237.GB23085@redhat.com Signed-off-by: Borislav Petkov <bp@suse.de> --- arch/x86/kernel/i387.c | 25 +++++++++---------------- 1 file changed, 9 insertions(+), 16 deletions(-) diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index 8416b5f85806..03cc0add8694 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -339,6 +339,7 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf) { + struct xsave_struct *xsave = &target->thread.fpu.state->xsave; int ret; if (!cpu_has_xsave) @@ -353,14 +354,12 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset, * memory layout in the thread struct, so that we can copy the entire * xstateregs to the user using one user_regset_copyout(). */ - memcpy(&target->thread.fpu.state->fxsave.sw_reserved, - xstate_fx_sw_bytes, sizeof(xstate_fx_sw_bytes)); - + memcpy(&xsave->i387.sw_reserved, + xstate_fx_sw_bytes, sizeof(xstate_fx_sw_bytes)); /* * Copy the xstate memory layout. */ - ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, - &target->thread.fpu.state->xsave, 0, -1); + ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, xsave, 0, -1); return ret; } @@ -368,8 +367,8 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, const void *kbuf, const void __user *ubuf) { + struct xsave_struct *xsave = &target->thread.fpu.state->xsave; int ret; - struct xsave_hdr_struct *xsave_hdr; if (!cpu_has_xsave) return -ENODEV; @@ -378,22 +377,16 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset, if (ret) return ret; - ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, - &target->thread.fpu.state->xsave, 0, -1); - + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, xsave, 0, -1); /* * mxcsr reserved bits must be masked to zero for security reasons. */ - target->thread.fpu.state->fxsave.mxcsr &= mxcsr_feature_mask; - - xsave_hdr = &target->thread.fpu.state->xsave.xsave_hdr; - - xsave_hdr->xstate_bv &= pcntxt_mask; + xsave->i387.mxcsr &= mxcsr_feature_mask; + xsave->xsave_hdr.xstate_bv &= pcntxt_mask; /* * These bits must be zero. */ - memset(xsave_hdr->reserved, 0, 48); - + memset(&xsave->xsave_hdr.reserved, 0, 48); return ret; } -- 2.2.0.33.gc18b867 ^ permalink raw reply related [flat|nested] 12+ messages in thread
* [PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths 2015-03-10 6:06 ` [PATCH 1/2] x86/fpu: Change xstateregs_get()/set() to use ->xsave.i387 rather than ->fxsave Borislav Petkov @ 2015-03-10 6:06 ` Borislav Petkov 0 siblings, 0 replies; 12+ messages in thread From: Borislav Petkov @ 2015-03-10 6:06 UTC (permalink / raw) To: Ingo Molnar; +Cc: X86 ML, LKML From: Oleg Nesterov <oleg@redhat.com> fx_finit() has 2 users but only fpu_finit() needs to nullify xstate, alloc_bootmem_align() in setup_init_fpu_buf() returns zero-filled memory. And note that both memset()'s look confusing. Yes, offsetof() is 0 for ->fxsave or ->fsave, but it would be more clean to turn them into a single memset() which nullifies fpu->state. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Tavis Ormandy <taviso@google.com> Cc: <x86@kernel.org> Link: http://lkml.kernel.org/r/20150302183257.GC23085@redhat.com Signed-off-by: Borislav Petkov <bp@suse.de> --- arch/x86/include/asm/fpu-internal.h | 1 - arch/x86/kernel/i387.c | 3 ++- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h index 61609b963eab..5fa1be21ac2a 100644 --- a/arch/x86/include/asm/fpu-internal.h +++ b/arch/x86/include/asm/fpu-internal.h @@ -135,7 +135,6 @@ static __always_inline __pure bool use_fxsr(void) static inline void fx_finit(struct i387_fxsave_struct *fx) { - memset(fx, 0, xstate_size); fx->cwd = 0x37f; fx->mxcsr = MXCSR_DEFAULT; } diff --git a/arch/x86/kernel/i387.c b/arch/x86/kernel/i387.c index 03cc0add8694..0f3de6674ae3 100644 --- a/arch/x86/kernel/i387.c +++ b/arch/x86/kernel/i387.c @@ -224,11 +224,12 @@ void fpu_finit(struct fpu *fpu) return; } + memset(fpu->state, 0, xstate_size); + if (cpu_has_fxsr) { fx_finit(&fpu->state->fxsave); } else { struct i387_fsave_struct *fp = &fpu->state->fsave; - memset(fp, 0, xstate_size); fp->cwd = 0xffff037fu; fp->swd = 0xffff0000u; fp->twd = 0xffffffffu; -- 2.2.0.33.gc18b867 ^ permalink raw reply related [flat|nested] 12+ messages in thread
end of thread, other threads:[~2015-03-10 10:08 UTC | newest]
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2015-03-02 18:32 ` [PATCH 0/2] x86/fpu: minor cleanups Oleg Nesterov
2015-03-02 18:32 ` [PATCH 1/2] x86/regsets: change xstateregs_get/set to use ->xsave.i387 rather than ->fxsave Oleg Nesterov
2015-03-03 19:23 ` Rik van Riel
2015-03-04 10:30 ` Borislav Petkov
2015-03-10 10:08 ` [tip:x86/fpu] x86/fpu: Change xstateregs_get()/set() to use -> xsave.i387 " tip-bot for Oleg Nesterov
2015-03-02 18:32 ` [PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths Oleg Nesterov
2015-03-03 22:01 ` Rik van Riel
2015-03-04 11:38 ` Borislav Petkov
2015-03-10 10:08 ` [tip:x86/fpu] x86/fpu: Factor out memset(xstate, 0) in fpu_finit( ) paths tip-bot for Oleg Nesterov
2015-03-09 18:08 [GIT PULL] x86/fpu cleanups Borislav Petkov
2015-03-10 6:06 ` [PATCH 1/2] x86/fpu: Change xstateregs_get()/set() to use ->xsave.i387 rather than ->fxsave Borislav Petkov
2015-03-10 6:06 ` [PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths Borislav Petkov
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