[PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths
From: Oleg Nesterov
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
Acked-by: Rik van Riel
Cc: Andy Lutomirski
Cc: Linus Torvalds
Cc: Tavis Ormandy
Cc:
Link: http://lkml.kernel.org/r/20150302183257.gc23...@redhat.com
Signed-off-by: Borislav Petkov
---
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(>state->fxsave);
} else {
struct i387_fsave_struct *fp = >state->fsave;
- memset(fp, 0, xstate_size);
fp->cwd = 0x037fu;
fp->swd = 0xu;
fp->twd = 0xu;
--
2.2.0.33.gc18b867
--
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[PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths
From: Oleg Nesterov o...@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 o...@redhat.com
Acked-by: Rik van Riel r...@redhat.com
Cc: Andy Lutomirski l...@amacapital.net
Cc: Linus Torvalds torva...@linux-foundation.org
Cc: Tavis Ormandy tav...@google.com
Cc: x...@kernel.org
Link: http://lkml.kernel.org/r/20150302183257.gc23...@redhat.com
Signed-off-by: Borislav Petkov b...@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 = 0x037fu;
fp-swd = 0xu;
fp-twd = 0xu;
--
2.2.0.33.gc18b867
--
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Re: [PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths
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 Applied, thanks. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths
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 o...@redhat.com Applied, thanks. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. -- -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths
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 Acked-by: Rik van Riel -- All rights reversed -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths
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 o...@redhat.com Acked-by: Rik van Riel r...@redhat.com -- All rights reversed -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths
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
---
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(>state->fxsave);
} else {
struct i387_fsave_struct *fp = >state->fsave;
- memset(fp, 0, xstate_size);
fp->cwd = 0x037fu;
fp->swd = 0xu;
fp->twd = 0xu;
--
1.5.5.1
--
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Please read the FAQ at http://www.tux.org/lkml/
[PATCH 2/2] x86/fpu: factor out memset(xstate, 0) in fpu_finit() paths
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 o...@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 = 0x037fu;
fp-swd = 0xu;
fp-twd = 0xu;
--
1.5.5.1
--
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