* [PATCH 0/5] x86/fpu/xstate: Fix XSAVES issues - Part 2
@ 2016-06-17 20:07 Yu-cheng Yu
2016-06-17 20:07 ` [PATCH 1/5] x86/fpu/xstate: Align xstate components according to CPUID Yu-cheng Yu
` (4 more replies)
0 siblings, 5 replies; 11+ messages in thread
From: Yu-cheng Yu @ 2016-06-17 20:07 UTC (permalink / raw)
To: linux-kernel, x86, H. Peter Anvin, Thomas Gleixner, Ingo Molnar
Cc: Dave Hansen, Sai Praneeth Prakhya, Ravi V. Shankar, Fenghua Yu,
Yu-cheng Yu
** Based on tip/master **
This is Part 2 of previous 13 XSAVES patches. Break it down to
smaller series. There are no code changes; only minor fixes in
the titles.
Yu-cheng Yu (5):
x86/fpu/xstate: Align xstate components according to CPUID
x86/fpu/xstate: Fix supervisor xstate component offset
x86/fpu/xstate: Fix PTRACE frames for XSAVES
x86/fpu/xstate: Fix XSTATE component offset print out
x86/fpu/xstate: Fix xstate_offsets, xstate_sizes for non-extended
xstates
arch/x86/include/asm/fpu/types.h | 1 +
arch/x86/include/asm/fpu/xstate.h | 8 +-
arch/x86/kernel/fpu/regset.c | 55 +++++--
arch/x86/kernel/fpu/xstate.c | 312 +++++++++++++++++++++++++++++++-------
4 files changed, 308 insertions(+), 68 deletions(-)
--
1.9.1
^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 1/5] x86/fpu/xstate: Align xstate components according to CPUID
2016-06-17 20:07 [PATCH 0/5] x86/fpu/xstate: Fix XSAVES issues - Part 2 Yu-cheng Yu
@ 2016-06-17 20:07 ` Yu-cheng Yu
2016-07-10 18:14 ` [tip:x86/fpu] " tip-bot for Yu-cheng Yu
2016-06-17 20:07 ` [PATCH 2/5] x86/fpu/xstate: Fix supervisor xstate component offset Yu-cheng Yu
` (3 subsequent siblings)
4 siblings, 1 reply; 11+ messages in thread
From: Yu-cheng Yu @ 2016-06-17 20:07 UTC (permalink / raw)
To: linux-kernel, x86, H. Peter Anvin, Thomas Gleixner, Ingo Molnar
Cc: Dave Hansen, Sai Praneeth Prakhya, Ravi V. Shankar, Fenghua Yu,
Yu-cheng Yu
CPUID function 0x0d, sub function (i, i > 1) returns in ecx[1] the
alignment requirement of component i when the compacted format is used.
If ecx[1] is 0, component i is located immediately following the preceding
component. If ecx[1] is 1, component i is located on the next 64-byte
boundary following the preceding component.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
---
arch/x86/kernel/fpu/xstate.c | 60 +++++++++++++++++++++++---------------------
1 file changed, 32 insertions(+), 28 deletions(-)
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 0b01f00..e6fcfcc6 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -270,6 +270,33 @@ static void __init print_xstate_features(void)
}
/*
+ * This check is important because it is easy to get XSTATE_*
+ * confused with XSTATE_BIT_*.
+ */
+#define CHECK_XFEATURE(nr) do { \
+ WARN_ON(nr < FIRST_EXTENDED_XFEATURE); \
+ WARN_ON(nr >= XFEATURE_MAX); \
+} while (0)
+
+/*
+ * We could cache this like xstate_size[], but we only use
+ * it here, so it would be a waste of space.
+ */
+static int xfeature_is_aligned(int xfeature_nr)
+{
+ u32 eax, ebx, ecx, edx;
+
+ CHECK_XFEATURE(xfeature_nr);
+ cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
+ /*
+ * The value returned by ECX[1] indicates the alignment
+ * of state component i when the compacted format
+ * of the extended region of an XSAVE area is used
+ */
+ return !!(ecx & 2);
+}
+
+/*
* This function sets up offsets and sizes of all extended states in
* xsave area. This supports both standard format and compacted format
* of the xsave aread.
@@ -306,10 +333,14 @@ static void __init setup_xstate_comp(void)
else
xstate_comp_sizes[i] = 0;
- if (i > FIRST_EXTENDED_XFEATURE)
+ if (i > FIRST_EXTENDED_XFEATURE) {
xstate_comp_offsets[i] = xstate_comp_offsets[i-1]
+ xstate_comp_sizes[i-1];
+ if (xfeature_is_aligned(i))
+ xstate_comp_offsets[i] =
+ ALIGN(xstate_comp_offsets[i], 64);
+ }
}
}
@@ -366,33 +397,6 @@ static int xfeature_is_user(int xfeature_nr)
}
*/
-/*
- * This check is important because it is easy to get XSTATE_*
- * confused with XSTATE_BIT_*.
- */
-#define CHECK_XFEATURE(nr) do { \
- WARN_ON(nr < FIRST_EXTENDED_XFEATURE); \
- WARN_ON(nr >= XFEATURE_MAX); \
-} while (0)
-
-/*
- * We could cache this like xstate_size[], but we only use
- * it here, so it would be a waste of space.
- */
-static int xfeature_is_aligned(int xfeature_nr)
-{
- u32 eax, ebx, ecx, edx;
-
- CHECK_XFEATURE(xfeature_nr);
- cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
- /*
- * The value returned by ECX[1] indicates the alignment
- * of state component i when the compacted format
- * of the extended region of an XSAVE area is used
- */
- return !!(ecx & 2);
-}
-
static int xfeature_uncompacted_offset(int xfeature_nr)
{
u32 eax, ebx, ecx, edx;
--
1.9.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 2/5] x86/fpu/xstate: Fix supervisor xstate component offset
2016-06-17 20:07 [PATCH 0/5] x86/fpu/xstate: Fix XSAVES issues - Part 2 Yu-cheng Yu
2016-06-17 20:07 ` [PATCH 1/5] x86/fpu/xstate: Align xstate components according to CPUID Yu-cheng Yu
@ 2016-06-17 20:07 ` Yu-cheng Yu
2016-07-10 18:14 ` [tip:x86/fpu] " tip-bot for Yu-cheng Yu
2016-06-17 20:07 ` [PATCH 3/5] x86/fpu/xstate: Fix PTRACE frames for XSAVES Yu-cheng Yu
` (2 subsequent siblings)
4 siblings, 1 reply; 11+ messages in thread
From: Yu-cheng Yu @ 2016-06-17 20:07 UTC (permalink / raw)
To: linux-kernel, x86, H. Peter Anvin, Thomas Gleixner, Ingo Molnar
Cc: Dave Hansen, Sai Praneeth Prakhya, Ravi V. Shankar, Fenghua Yu,
Yu-cheng Yu
CPUID function 0x0d, sub function (i, i > 1) returns in ebx the offset of
xstate component i. Zero is returned for a supervisor state. A supervisor
state can only be saved by XSAVES and XSAVES uses a compacted format.
There is no fixed offset for a supervisor state. This patch checks and
makes sure a supervisor state offset is not recorded or mis-used. This has
no effect in practice as we currently use no supervisor states, but it
would be good to fix.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
---
arch/x86/include/asm/fpu/types.h | 1 +
arch/x86/include/asm/fpu/xstate.h | 3 ++
arch/x86/kernel/fpu/xstate.c | 62 ++++++++++++++++++++++++---------------
3 files changed, 43 insertions(+), 23 deletions(-)
diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h
index 36b90bb..12dd648 100644
--- a/arch/x86/include/asm/fpu/types.h
+++ b/arch/x86/include/asm/fpu/types.h
@@ -122,6 +122,7 @@ enum xfeature {
#define XFEATURE_MASK_OPMASK (1 << XFEATURE_OPMASK)
#define XFEATURE_MASK_ZMM_Hi256 (1 << XFEATURE_ZMM_Hi256)
#define XFEATURE_MASK_Hi16_ZMM (1 << XFEATURE_Hi16_ZMM)
+#define XFEATURE_MASK_PT (1 << XFEATURE_PT_UNIMPLEMENTED_SO_FAR)
#define XFEATURE_MASK_PKRU (1 << XFEATURE_PKRU)
#define XFEATURE_MASK_FPSSE (XFEATURE_MASK_FP | XFEATURE_MASK_SSE)
diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h
index d812cf3..92f376c 100644
--- a/arch/x86/include/asm/fpu/xstate.h
+++ b/arch/x86/include/asm/fpu/xstate.h
@@ -18,6 +18,9 @@
#define XSAVE_YMM_SIZE 256
#define XSAVE_YMM_OFFSET (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET)
+/* Supervisor features */
+#define XFEATURE_MASK_SUPERVISOR (XFEATURE_MASK_PT)
+
/* Supported features which support lazy state saving */
#define XFEATURE_MASK_LAZY (XFEATURE_MASK_FP | \
XFEATURE_MASK_SSE | \
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index e6fcfcc6..ec7e53b 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -112,6 +112,27 @@ int cpu_has_xfeatures(u64 xfeatures_needed, const char **feature_name)
}
EXPORT_SYMBOL_GPL(cpu_has_xfeatures);
+static int xfeature_is_supervisor(int xfeature_nr)
+{
+ /*
+ * We currently do not support supervisor states, but if
+ * we did, we could find out like this.
+ *
+ * SDM says: If state component i is a user state component,
+ * ECX[0] return 0; if state component i is a supervisor
+ * state component, ECX[0] returns 1.
+ */
+ u32 eax, ebx, ecx, edx;
+
+ cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
+ return !!(ecx & 1);
+}
+
+static int xfeature_is_user(int xfeature_nr)
+{
+ return !xfeature_is_supervisor(xfeature_nr);
+}
+
/*
* When executing XSAVEOPT (or other optimized XSAVE instructions), if
* a processor implementation detects that an FPU state component is still
@@ -230,7 +251,14 @@ static void __init setup_xstate_features(void)
continue;
cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx);
- xstate_offsets[i] = ebx;
+
+ /*
+ * If an xfeature is supervisor state, the offset
+ * in ebx is invalid. We leave it to -1.
+ */
+ if (xfeature_is_user(i))
+ xstate_offsets[i] = ebx;
+
xstate_sizes[i] = eax;
/*
* In our xstate size checks, we assume that the
@@ -375,32 +403,20 @@ static void __init setup_init_fpu_buf(void)
copy_xregs_to_kernel_booting(&init_fpstate.xsave);
}
-static int xfeature_is_supervisor(int xfeature_nr)
-{
- /*
- * We currently do not support supervisor states, but if
- * we did, we could find out like this.
- *
- * SDM says: If state component i is a user state component,
- * ECX[0] return 0; if state component i is a supervisor
- * state component, ECX[0] returns 1.
- u32 eax, ebx, ecx, edx;
- cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx;
- return !!(ecx & 1);
- */
- return 0;
-}
-/*
-static int xfeature_is_user(int xfeature_nr)
-{
- return !xfeature_is_supervisor(xfeature_nr);
-}
-*/
-
static int xfeature_uncompacted_offset(int xfeature_nr)
{
u32 eax, ebx, ecx, edx;
+ /*
+ * Only XSAVES supports supervisor states and it uses compacted
+ * format. Checking a supervisor state's uncompacted offset is
+ * an error.
+ */
+ if (XFEATURE_MASK_SUPERVISOR & (1 << xfeature_nr)) {
+ WARN_ONCE(1, "No fixed offset for xstate %d\n", xfeature_nr);
+ return -1;
+ }
+
CHECK_XFEATURE(xfeature_nr);
cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
return ebx;
--
1.9.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 3/5] x86/fpu/xstate: Fix PTRACE frames for XSAVES
2016-06-17 20:07 [PATCH 0/5] x86/fpu/xstate: Fix XSAVES issues - Part 2 Yu-cheng Yu
2016-06-17 20:07 ` [PATCH 1/5] x86/fpu/xstate: Align xstate components according to CPUID Yu-cheng Yu
2016-06-17 20:07 ` [PATCH 2/5] x86/fpu/xstate: Fix supervisor xstate component offset Yu-cheng Yu
@ 2016-06-17 20:07 ` Yu-cheng Yu
2016-07-10 18:14 ` [tip:x86/fpu] " tip-bot for Yu-cheng Yu
2016-06-17 20:07 ` [PATCH 4/5] x86/fpu/xstate: Fix XSTATE component offset print out Yu-cheng Yu
2016-06-17 20:07 ` [PATCH 5/5] x86/fpu/xstate: Fix xstate_offsets, xstate_sizes for non-extended xstates Yu-cheng Yu
4 siblings, 1 reply; 11+ messages in thread
From: Yu-cheng Yu @ 2016-06-17 20:07 UTC (permalink / raw)
To: linux-kernel, x86, H. Peter Anvin, Thomas Gleixner, Ingo Molnar
Cc: Dave Hansen, Sai Praneeth Prakhya, Ravi V. Shankar, Fenghua Yu,
Yu-cheng Yu
XSAVES uses compacted format and is a kernel instruction. The kernel
should use standard-format, non-supervisor state data for PTRACE.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
---
arch/x86/include/asm/fpu/xstate.h | 5 +-
arch/x86/kernel/fpu/regset.c | 55 +++++++++----
arch/x86/kernel/fpu/xstate.c | 167 +++++++++++++++++++++++++++++++++++++-
3 files changed, 210 insertions(+), 17 deletions(-)
diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h
index 92f376c..ae55a43 100644
--- a/arch/x86/include/asm/fpu/xstate.h
+++ b/arch/x86/include/asm/fpu/xstate.h
@@ -51,5 +51,8 @@ void fpu__xstate_clear_all_cpu_caps(void);
void *get_xsave_addr(struct xregs_state *xsave, int xstate);
const void *get_xsave_field_ptr(int xstate_field);
int using_compacted_format(void);
-
+int copyout_from_xsaves(unsigned int pos, unsigned int count, void *kbuf,
+ void __user *ubuf, struct xregs_state *xsave);
+int copyin_to_xsaves(const void *kbuf, const void __user *ubuf,
+ struct xregs_state *xsave);
#endif
diff --git a/arch/x86/kernel/fpu/regset.c b/arch/x86/kernel/fpu/regset.c
index 81422df..5248491 100644
--- a/arch/x86/kernel/fpu/regset.c
+++ b/arch/x86/kernel/fpu/regset.c
@@ -4,6 +4,7 @@
#include <asm/fpu/internal.h>
#include <asm/fpu/signal.h>
#include <asm/fpu/regset.h>
+#include <asm/fpu/xstate.h>
/*
* The xstateregs_active() routine is the same as the regset_fpregs_active() routine,
@@ -85,21 +86,28 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset,
if (!boot_cpu_has(X86_FEATURE_XSAVE))
return -ENODEV;
- fpu__activate_fpstate_read(fpu);
-
xsave = &fpu->state.xsave;
- /*
- * Copy the 48bytes defined by the software first into the xstate
- * memory layout in the thread struct, so that we can copy the entire
- * xstateregs to the user using one user_regset_copyout().
- */
- 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, xsave, 0, -1);
+ fpu__activate_fpstate_read(fpu);
+
+ if (using_compacted_format()) {
+ ret = copyout_from_xsaves(pos, count, kbuf, ubuf, xsave);
+ } else {
+ fpstate_sanitize_xstate(fpu);
+ /*
+ * Copy the 48 bytes defined by the software into the xsave
+ * area in the thread struct, so that we can copy the whole
+ * area to user using one user_regset_copyout().
+ */
+ 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, xsave, 0, -1);
+ }
return ret;
}
@@ -114,11 +122,28 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset,
if (!boot_cpu_has(X86_FEATURE_XSAVE))
return -ENODEV;
- fpu__activate_fpstate_write(fpu);
+ /*
+ * A whole standard-format XSAVE buffer is needed.
+ */
+ if ((pos != 0) || (count < fpu_user_xstate_size))
+ return -EFAULT;
xsave = &fpu->state.xsave;
- ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, xsave, 0, -1);
+ fpu__activate_fpstate_write(fpu);
+
+ if (boot_cpu_has(X86_FEATURE_XSAVES))
+ ret = copyin_to_xsaves(kbuf, ubuf, xsave);
+ else
+ ret = user_regset_copyin(&pos,
+ &count, &kbuf, &ubuf, xsave, 0, -1);
+
+ /*
+ * In case of failure, mark all states as init.
+ */
+ if (ret)
+ fpstate_init(&fpu->state);
+
/*
* mxcsr reserved bits must be masked to zero for security reasons.
*/
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index ec7e53b..8d5fb03 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -11,6 +11,7 @@
#include <asm/fpu/internal.h>
#include <asm/fpu/signal.h>
#include <asm/fpu/regset.h>
+#include <asm/fpu/xstate.h>
#include <asm/tlbflush.h>
@@ -697,7 +698,13 @@ void __init fpu__init_system_xstate(void)
return;
}
- update_regset_xstate_info(fpu_kernel_xstate_size, xfeatures_mask);
+ /*
+ * Update info used for ptrace frames; use standard-format size and no
+ * supervisor xstates.
+ */
+ update_regset_xstate_info(fpu_user_xstate_size,
+ xfeatures_mask & ~XFEATURE_MASK_SUPERVISOR);
+
fpu__init_prepare_fx_sw_frame();
setup_init_fpu_buf();
setup_xstate_comp();
@@ -968,3 +975,161 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
return 0;
}
+
+/*
+ * This is similar to user_regset_copyout(), but will not add offset to
+ * the source data pointer or increment pos, count, kbuf, and ubuf.
+ */
+static inline int xstate_copyout(unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf,
+ const void *data, const int start_pos,
+ const int end_pos)
+{
+ if ((count == 0) || (pos < start_pos))
+ return 0;
+
+ if (end_pos < 0 || pos < end_pos) {
+ unsigned int copy =
+ (end_pos < 0 ? count : min(count, end_pos - pos));
+
+ if (kbuf)
+ memcpy(kbuf + pos, data, copy);
+ else if (__copy_to_user(ubuf + pos, data, copy))
+ return -EFAULT;
+ }
+ return 0;
+}
+
+/*
+ * Convert from kernel XSAVES compacted format to standard format and copy
+ * to a ptrace buffer. It supports partial copy but pos always starts from
+ * zero. This is called from xstateregs_get() and there we check the cpu
+ * has XSAVES.
+ */
+int copyout_from_xsaves(unsigned int pos, unsigned int count, void *kbuf,
+ void __user *ubuf, struct xregs_state *xsave)
+{
+ unsigned int offset, size;
+ int ret, i;
+ struct xstate_header header;
+
+ /*
+ * Currently copy_regset_to_user() starts from pos 0.
+ */
+ if (unlikely(pos != 0))
+ return -EFAULT;
+
+ /*
+ * The destination is a ptrace buffer; we put in only user xstates.
+ */
+ memset(&header, 0, sizeof(header));
+ header.xfeatures = xsave->header.xfeatures;
+ header.xfeatures &= ~XFEATURE_MASK_SUPERVISOR;
+
+ /*
+ * Copy xregs_state->header.
+ */
+ offset = offsetof(struct xregs_state, header);
+ size = sizeof(header);
+
+ ret = xstate_copyout(offset, size, kbuf, ubuf, &header, 0, count);
+
+ if (ret)
+ return ret;
+
+ for (i = 0; i < XFEATURE_MAX; i++) {
+ /*
+ * Copy only in-use xstates.
+ */
+ if ((header.xfeatures >> i) & 1) {
+ void *src = __raw_xsave_addr(xsave, 1 << i);
+
+ offset = xstate_offsets[i];
+ size = xstate_sizes[i];
+
+ ret = xstate_copyout(offset, size, kbuf, ubuf, src, 0,
+ count);
+
+ if (ret)
+ return ret;
+
+ if (offset + size >= count)
+ break;
+ }
+
+ }
+
+ /*
+ * Fill xsave->i387.sw_reserved value for ptrace frame.
+ */
+ offset = offsetof(struct fxregs_state, sw_reserved);
+ size = sizeof(xstate_fx_sw_bytes);
+
+ ret = xstate_copyout(offset, size, kbuf, ubuf, xstate_fx_sw_bytes, 0,
+ count);
+
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+/*
+ * Convert from a ptrace standard-format buffer to kernel XSAVES format
+ * and copy to the target thread. This is called from xstateregs_set() and
+ * there we check the cpu has XSAVES and a whole standard-sized buffer
+ * exists.
+ */
+int copyin_to_xsaves(const void *kbuf, const void __user *ubuf,
+ struct xregs_state *xsave)
+{
+ unsigned int offset, size;
+ int i;
+ u64 xfeatures;
+ u64 allowed_features;
+
+ offset = offsetof(struct xregs_state, header);
+ size = sizeof(xfeatures);
+
+ if (kbuf)
+ memcpy(&xfeatures, kbuf + offset, size);
+ else if (__copy_from_user(&xfeatures, ubuf + offset, size))
+ return -EFAULT;
+
+ /*
+ * Reject if the user sets any disabled or supervisor features.
+ */
+ allowed_features = xfeatures_mask & ~XFEATURE_MASK_SUPERVISOR;
+
+ if (xfeatures & ~allowed_features)
+ return -EINVAL;
+
+ for (i = 0; i < XFEATURE_MAX; i++) {
+ u64 mask = ((u64)1 << i);
+
+ if (xfeatures & mask) {
+ void *dst = __raw_xsave_addr(xsave, 1 << i);
+
+ offset = xstate_offsets[i];
+ size = xstate_sizes[i];
+
+ if (kbuf)
+ memcpy(dst, kbuf + offset, size);
+ else if (__copy_from_user(dst, ubuf + offset, size))
+ return -EFAULT;
+ }
+ }
+
+ /*
+ * The state that came in from userspace was user-state only.
+ * Mask all the user states out of 'xfeatures'.
+ */
+ xsave->header.xfeatures &= XFEATURE_MASK_SUPERVISOR;
+
+ /*
+ * Add back in the features that came in from userspace.
+ */
+ xsave->header.xfeatures |= xfeatures;
+
+ return 0;
+}
--
1.9.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 4/5] x86/fpu/xstate: Fix XSTATE component offset print out
2016-06-17 20:07 [PATCH 0/5] x86/fpu/xstate: Fix XSAVES issues - Part 2 Yu-cheng Yu
` (2 preceding siblings ...)
2016-06-17 20:07 ` [PATCH 3/5] x86/fpu/xstate: Fix PTRACE frames for XSAVES Yu-cheng Yu
@ 2016-06-17 20:07 ` Yu-cheng Yu
2016-07-10 18:15 ` [tip:x86/fpu] " tip-bot for Yu-cheng Yu
2016-06-17 20:07 ` [PATCH 5/5] x86/fpu/xstate: Fix xstate_offsets, xstate_sizes for non-extended xstates Yu-cheng Yu
4 siblings, 1 reply; 11+ messages in thread
From: Yu-cheng Yu @ 2016-06-17 20:07 UTC (permalink / raw)
To: linux-kernel, x86, H. Peter Anvin, Thomas Gleixner, Ingo Molnar
Cc: Dave Hansen, Sai Praneeth Prakhya, Ravi V. Shankar, Fenghua Yu,
Yu-cheng Yu
Component offset print out was incorrect for XSAVES. Correct it and move
to a separate function.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
---
arch/x86/kernel/fpu/xstate.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 8d5fb03..bae8840 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -269,8 +269,6 @@ static void __init setup_xstate_features(void)
WARN_ONCE(last_good_offset > xstate_offsets[i],
"x86/fpu: misordered xstate at %d\n", last_good_offset);
last_good_offset = xstate_offsets[i];
-
- printk(KERN_INFO "x86/fpu: xstate_offset[%d]: %4d, xstate_sizes[%d]: %4d\n", i, ebx, i, eax);
}
}
@@ -374,6 +372,21 @@ static void __init setup_xstate_comp(void)
}
/*
+ * Print out xstate component offsets and sizes
+ */
+static void __init print_xstate_offset_size(void)
+{
+ int i;
+
+ for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
+ if (!xfeature_enabled(i))
+ continue;
+ pr_info("x86/fpu: xstate_offset[%d]: %4d, xstate_sizes[%d]: %4d\n",
+ i, xstate_comp_offsets[i], i, xstate_sizes[i]);
+ }
+}
+
+/*
* setup the xstate image representing the init state
*/
static void __init setup_init_fpu_buf(void)
@@ -708,6 +721,7 @@ void __init fpu__init_system_xstate(void)
fpu__init_prepare_fx_sw_frame();
setup_init_fpu_buf();
setup_xstate_comp();
+ print_xstate_offset_size();
pr_info("x86/fpu: Enabled xstate features 0x%llx, context size is %d bytes, using '%s' format.\n",
xfeatures_mask,
--
1.9.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 5/5] x86/fpu/xstate: Fix xstate_offsets, xstate_sizes for non-extended xstates
2016-06-17 20:07 [PATCH 0/5] x86/fpu/xstate: Fix XSAVES issues - Part 2 Yu-cheng Yu
` (3 preceding siblings ...)
2016-06-17 20:07 ` [PATCH 4/5] x86/fpu/xstate: Fix XSTATE component offset print out Yu-cheng Yu
@ 2016-06-17 20:07 ` Yu-cheng Yu
2016-07-10 18:15 ` [tip:x86/fpu] " tip-bot for Yu-cheng Yu
4 siblings, 1 reply; 11+ messages in thread
From: Yu-cheng Yu @ 2016-06-17 20:07 UTC (permalink / raw)
To: linux-kernel, x86, H. Peter Anvin, Thomas Gleixner, Ingo Molnar
Cc: Dave Hansen, Sai Praneeth Prakhya, Ravi V. Shankar, Fenghua Yu,
Yu-cheng Yu
The arrays xstate_offsets[] and xstate_sizes[] record XSAVE standard-
format offsets and sizes. Values for non-extended state components
fpu and xmm's were not initialized or used. Ptrace format conversion
needs them. Fix it.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
---
arch/x86/kernel/fpu/xstate.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index bae8840..822a18f 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -246,6 +246,15 @@ static void __init setup_xstate_features(void)
/* start at the beginnning of the "extended state" */
unsigned int last_good_offset = offsetof(struct xregs_state,
extended_state_area);
+ /*
+ * The FP xstates and SSE xstates are legacy states. They are always
+ * in the fixed offsets in the xsave area in either compacted form
+ * or standard form.
+ */
+ xstate_offsets[0] = 0;
+ xstate_sizes[0] = offsetof(struct fxregs_state, xmm_space);
+ xstate_offsets[1] = xstate_sizes[0];
+ xstate_sizes[1] = FIELD_SIZEOF(struct fxregs_state, xmm_space);
for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
if (!xfeature_enabled(i))
--
1.9.1
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [tip:x86/fpu] x86/fpu/xstate: Align xstate components according to CPUID
2016-06-17 20:07 ` [PATCH 1/5] x86/fpu/xstate: Align xstate components according to CPUID Yu-cheng Yu
@ 2016-07-10 18:14 ` tip-bot for Yu-cheng Yu
0 siblings, 0 replies; 11+ messages in thread
From: tip-bot for Yu-cheng Yu @ 2016-07-10 18:14 UTC (permalink / raw)
To: linux-tip-commits
Cc: tglx, fenghua.yu, bp, jpoimboe, brgerst, hpa, yu-cheng.yu,
sai.praneeth.prakhya, torvalds, dvlasenk, dave.hansen, peterz,
quentin.casasnovas, mingo, luto, ravi.v.shankar, dave.hansen,
oleg, linux-kernel
Commit-ID: 03482e08a87d24e5c8c23e6981c482e832cf3bdc
Gitweb: http://git.kernel.org/tip/03482e08a87d24e5c8c23e6981c482e832cf3bdc
Author: Yu-cheng Yu <yu-cheng.yu@intel.com>
AuthorDate: Fri, 17 Jun 2016 13:07:15 -0700
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Sun, 10 Jul 2016 17:12:10 +0200
x86/fpu/xstate: Align xstate components according to CPUID
CPUID function 0x0d, sub function (i, i > 1) returns in ecx[1] the
alignment requirement of component 'i' when the compacted format is used.
If ecx[1] is 0, component 'i' is located immediately following the preceding
component. If ecx[1] is 1, component 'i' is located on the next 64-byte
boundary following the preceding component.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/331e2bef1a0a7a584f06adde095b6bbfbe166472.1466179491.git.yu-cheng.yu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/fpu/xstate.c | 60 +++++++++++++++++++++++---------------------
1 file changed, 32 insertions(+), 28 deletions(-)
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 0b01f00..7963029 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -270,6 +270,33 @@ static void __init print_xstate_features(void)
}
/*
+ * This check is important because it is easy to get XSTATE_*
+ * confused with XSTATE_BIT_*.
+ */
+#define CHECK_XFEATURE(nr) do { \
+ WARN_ON(nr < FIRST_EXTENDED_XFEATURE); \
+ WARN_ON(nr >= XFEATURE_MAX); \
+} while (0)
+
+/*
+ * We could cache this like xstate_size[], but we only use
+ * it here, so it would be a waste of space.
+ */
+static int xfeature_is_aligned(int xfeature_nr)
+{
+ u32 eax, ebx, ecx, edx;
+
+ CHECK_XFEATURE(xfeature_nr);
+ cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
+ /*
+ * The value returned by ECX[1] indicates the alignment
+ * of state component 'i' when the compacted format
+ * of the extended region of an XSAVE area is used:
+ */
+ return !!(ecx & 2);
+}
+
+/*
* This function sets up offsets and sizes of all extended states in
* xsave area. This supports both standard format and compacted format
* of the xsave aread.
@@ -306,10 +333,14 @@ static void __init setup_xstate_comp(void)
else
xstate_comp_sizes[i] = 0;
- if (i > FIRST_EXTENDED_XFEATURE)
+ if (i > FIRST_EXTENDED_XFEATURE) {
xstate_comp_offsets[i] = xstate_comp_offsets[i-1]
+ xstate_comp_sizes[i-1];
+ if (xfeature_is_aligned(i))
+ xstate_comp_offsets[i] =
+ ALIGN(xstate_comp_offsets[i], 64);
+ }
}
}
@@ -366,33 +397,6 @@ static int xfeature_is_user(int xfeature_nr)
}
*/
-/*
- * This check is important because it is easy to get XSTATE_*
- * confused with XSTATE_BIT_*.
- */
-#define CHECK_XFEATURE(nr) do { \
- WARN_ON(nr < FIRST_EXTENDED_XFEATURE); \
- WARN_ON(nr >= XFEATURE_MAX); \
-} while (0)
-
-/*
- * We could cache this like xstate_size[], but we only use
- * it here, so it would be a waste of space.
- */
-static int xfeature_is_aligned(int xfeature_nr)
-{
- u32 eax, ebx, ecx, edx;
-
- CHECK_XFEATURE(xfeature_nr);
- cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
- /*
- * The value returned by ECX[1] indicates the alignment
- * of state component i when the compacted format
- * of the extended region of an XSAVE area is used
- */
- return !!(ecx & 2);
-}
-
static int xfeature_uncompacted_offset(int xfeature_nr)
{
u32 eax, ebx, ecx, edx;
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [tip:x86/fpu] x86/fpu/xstate: Fix supervisor xstate component offset
2016-06-17 20:07 ` [PATCH 2/5] x86/fpu/xstate: Fix supervisor xstate component offset Yu-cheng Yu
@ 2016-07-10 18:14 ` tip-bot for Yu-cheng Yu
0 siblings, 0 replies; 11+ messages in thread
From: tip-bot for Yu-cheng Yu @ 2016-07-10 18:14 UTC (permalink / raw)
To: linux-tip-commits
Cc: quentin.casasnovas, dave.hansen, ravi.v.shankar, oleg,
fenghua.yu, sai.praneeth.prakhya, hpa, dave.hansen, dvlasenk,
tglx, mingo, luto, jpoimboe, peterz, brgerst, yu-cheng.yu,
linux-kernel, bp, torvalds
Commit-ID: 1499ce2dd45afddea2e84f9f920890cf88384c4e
Gitweb: http://git.kernel.org/tip/1499ce2dd45afddea2e84f9f920890cf88384c4e
Author: Yu-cheng Yu <yu-cheng.yu@intel.com>
AuthorDate: Fri, 17 Jun 2016 13:07:16 -0700
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Sun, 10 Jul 2016 17:12:10 +0200
x86/fpu/xstate: Fix supervisor xstate component offset
CPUID function 0x0d, sub function (i, i > 1) returns in ebx the offset of
xstate component i. Zero is returned for a supervisor state. A supervisor
state can only be saved by XSAVES and XSAVES uses a compacted format.
There is no fixed offset for a supervisor state. This patch checks and
makes sure a supervisor state offset is not recorded or mis-used. This has
no effect in practice as we currently use no supervisor states, but it
would be good to fix.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/81b29e40d35d4cec9f2511a856fe769f34935a3f.1466179491.git.yu-cheng.yu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/include/asm/fpu/types.h | 1 +
arch/x86/include/asm/fpu/xstate.h | 3 ++
arch/x86/kernel/fpu/xstate.c | 62 ++++++++++++++++++++++++---------------
3 files changed, 43 insertions(+), 23 deletions(-)
diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h
index 36b90bb..12dd648 100644
--- a/arch/x86/include/asm/fpu/types.h
+++ b/arch/x86/include/asm/fpu/types.h
@@ -122,6 +122,7 @@ enum xfeature {
#define XFEATURE_MASK_OPMASK (1 << XFEATURE_OPMASK)
#define XFEATURE_MASK_ZMM_Hi256 (1 << XFEATURE_ZMM_Hi256)
#define XFEATURE_MASK_Hi16_ZMM (1 << XFEATURE_Hi16_ZMM)
+#define XFEATURE_MASK_PT (1 << XFEATURE_PT_UNIMPLEMENTED_SO_FAR)
#define XFEATURE_MASK_PKRU (1 << XFEATURE_PKRU)
#define XFEATURE_MASK_FPSSE (XFEATURE_MASK_FP | XFEATURE_MASK_SSE)
diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h
index d812cf3..92f376c 100644
--- a/arch/x86/include/asm/fpu/xstate.h
+++ b/arch/x86/include/asm/fpu/xstate.h
@@ -18,6 +18,9 @@
#define XSAVE_YMM_SIZE 256
#define XSAVE_YMM_OFFSET (XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET)
+/* Supervisor features */
+#define XFEATURE_MASK_SUPERVISOR (XFEATURE_MASK_PT)
+
/* Supported features which support lazy state saving */
#define XFEATURE_MASK_LAZY (XFEATURE_MASK_FP | \
XFEATURE_MASK_SSE | \
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 7963029..02786fb 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -112,6 +112,27 @@ int cpu_has_xfeatures(u64 xfeatures_needed, const char **feature_name)
}
EXPORT_SYMBOL_GPL(cpu_has_xfeatures);
+static int xfeature_is_supervisor(int xfeature_nr)
+{
+ /*
+ * We currently do not support supervisor states, but if
+ * we did, we could find out like this.
+ *
+ * SDM says: If state component 'i' is a user state component,
+ * ECX[0] return 0; if state component i is a supervisor
+ * state component, ECX[0] returns 1.
+ */
+ u32 eax, ebx, ecx, edx;
+
+ cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
+ return !!(ecx & 1);
+}
+
+static int xfeature_is_user(int xfeature_nr)
+{
+ return !xfeature_is_supervisor(xfeature_nr);
+}
+
/*
* When executing XSAVEOPT (or other optimized XSAVE instructions), if
* a processor implementation detects that an FPU state component is still
@@ -230,7 +251,14 @@ static void __init setup_xstate_features(void)
continue;
cpuid_count(XSTATE_CPUID, i, &eax, &ebx, &ecx, &edx);
- xstate_offsets[i] = ebx;
+
+ /*
+ * If an xfeature is supervisor state, the offset
+ * in EBX is invalid. We leave it to -1.
+ */
+ if (xfeature_is_user(i))
+ xstate_offsets[i] = ebx;
+
xstate_sizes[i] = eax;
/*
* In our xstate size checks, we assume that the
@@ -375,32 +403,20 @@ static void __init setup_init_fpu_buf(void)
copy_xregs_to_kernel_booting(&init_fpstate.xsave);
}
-static int xfeature_is_supervisor(int xfeature_nr)
-{
- /*
- * We currently do not support supervisor states, but if
- * we did, we could find out like this.
- *
- * SDM says: If state component i is a user state component,
- * ECX[0] return 0; if state component i is a supervisor
- * state component, ECX[0] returns 1.
- u32 eax, ebx, ecx, edx;
- cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx;
- return !!(ecx & 1);
- */
- return 0;
-}
-/*
-static int xfeature_is_user(int xfeature_nr)
-{
- return !xfeature_is_supervisor(xfeature_nr);
-}
-*/
-
static int xfeature_uncompacted_offset(int xfeature_nr)
{
u32 eax, ebx, ecx, edx;
+ /*
+ * Only XSAVES supports supervisor states and it uses compacted
+ * format. Checking a supervisor state's uncompacted offset is
+ * an error.
+ */
+ if (XFEATURE_MASK_SUPERVISOR & (1 << xfeature_nr)) {
+ WARN_ONCE(1, "No fixed offset for xstate %d\n", xfeature_nr);
+ return -1;
+ }
+
CHECK_XFEATURE(xfeature_nr);
cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
return ebx;
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [tip:x86/fpu] x86/fpu/xstate: Fix PTRACE frames for XSAVES
2016-06-17 20:07 ` [PATCH 3/5] x86/fpu/xstate: Fix PTRACE frames for XSAVES Yu-cheng Yu
@ 2016-07-10 18:14 ` tip-bot for Yu-cheng Yu
0 siblings, 0 replies; 11+ messages in thread
From: tip-bot for Yu-cheng Yu @ 2016-07-10 18:14 UTC (permalink / raw)
To: linux-tip-commits
Cc: peterz, yu-cheng.yu, oleg, quentin.casasnovas, brgerst, bp, luto,
dave.hansen, ravi.v.shankar, mingo, dvlasenk,
sai.praneeth.prakhya, tglx, torvalds, hpa, jpoimboe, dave.hansen,
linux-kernel, fenghua.yu
Commit-ID: 91c3dba7dbc199191272f4a9863f86ea3bfd679f
Gitweb: http://git.kernel.org/tip/91c3dba7dbc199191272f4a9863f86ea3bfd679f
Author: Yu-cheng Yu <yu-cheng.yu@intel.com>
AuthorDate: Fri, 17 Jun 2016 13:07:17 -0700
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Sun, 10 Jul 2016 17:12:10 +0200
x86/fpu/xstate: Fix PTRACE frames for XSAVES
XSAVES uses compacted format and is a kernel instruction. The kernel
should use standard-format, non-supervisor state data for PTRACE.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
[ Edited away artificial linebreaks. ]
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/de3d80949001305fe389799973b675cab055c457.1466179491.git.yu-cheng.yu@intel.com
[ Made various readability edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/include/asm/fpu/xstate.h | 5 +-
arch/x86/kernel/fpu/regset.c | 52 +++++++----
arch/x86/kernel/fpu/xstate.c | 183 ++++++++++++++++++++++++++++++++++++--
3 files changed, 216 insertions(+), 24 deletions(-)
diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h
index 92f376c..ae55a43 100644
--- a/arch/x86/include/asm/fpu/xstate.h
+++ b/arch/x86/include/asm/fpu/xstate.h
@@ -51,5 +51,8 @@ void fpu__xstate_clear_all_cpu_caps(void);
void *get_xsave_addr(struct xregs_state *xsave, int xstate);
const void *get_xsave_field_ptr(int xstate_field);
int using_compacted_format(void);
-
+int copyout_from_xsaves(unsigned int pos, unsigned int count, void *kbuf,
+ void __user *ubuf, struct xregs_state *xsave);
+int copyin_to_xsaves(const void *kbuf, const void __user *ubuf,
+ struct xregs_state *xsave);
#endif
diff --git a/arch/x86/kernel/fpu/regset.c b/arch/x86/kernel/fpu/regset.c
index 81422df..c114b13 100644
--- a/arch/x86/kernel/fpu/regset.c
+++ b/arch/x86/kernel/fpu/regset.c
@@ -4,6 +4,7 @@
#include <asm/fpu/internal.h>
#include <asm/fpu/signal.h>
#include <asm/fpu/regset.h>
+#include <asm/fpu/xstate.h>
/*
* The xstateregs_active() routine is the same as the regset_fpregs_active() routine,
@@ -85,21 +86,26 @@ int xstateregs_get(struct task_struct *target, const struct user_regset *regset,
if (!boot_cpu_has(X86_FEATURE_XSAVE))
return -ENODEV;
- fpu__activate_fpstate_read(fpu);
-
xsave = &fpu->state.xsave;
- /*
- * Copy the 48bytes defined by the software first into the xstate
- * memory layout in the thread struct, so that we can copy the entire
- * xstateregs to the user using one user_regset_copyout().
- */
- 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, xsave, 0, -1);
+ fpu__activate_fpstate_read(fpu);
+
+ if (using_compacted_format()) {
+ ret = copyout_from_xsaves(pos, count, kbuf, ubuf, xsave);
+ } else {
+ fpstate_sanitize_xstate(fpu);
+ /*
+ * Copy the 48 bytes defined by the software into the xsave
+ * area in the thread struct, so that we can copy the whole
+ * area to user using one user_regset_copyout().
+ */
+ 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, xsave, 0, -1);
+ }
return ret;
}
@@ -114,11 +120,27 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset,
if (!boot_cpu_has(X86_FEATURE_XSAVE))
return -ENODEV;
- fpu__activate_fpstate_write(fpu);
+ /*
+ * A whole standard-format XSAVE buffer is needed:
+ */
+ if ((pos != 0) || (count < fpu_user_xstate_size))
+ return -EFAULT;
xsave = &fpu->state.xsave;
- ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, xsave, 0, -1);
+ fpu__activate_fpstate_write(fpu);
+
+ if (boot_cpu_has(X86_FEATURE_XSAVES))
+ ret = copyin_to_xsaves(kbuf, ubuf, xsave);
+ else
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, xsave, 0, -1);
+
+ /*
+ * In case of failure, mark all states as init:
+ */
+ if (ret)
+ fpstate_init(&fpu->state);
+
/*
* mxcsr reserved bits must be masked to zero for security reasons.
*/
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 02786fb..56c0e70 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -11,6 +11,7 @@
#include <asm/fpu/internal.h>
#include <asm/fpu/signal.h>
#include <asm/fpu/regset.h>
+#include <asm/fpu/xstate.h>
#include <asm/tlbflush.h>
@@ -697,7 +698,12 @@ void __init fpu__init_system_xstate(void)
return;
}
- update_regset_xstate_info(fpu_kernel_xstate_size, xfeatures_mask);
+ /*
+ * Update info used for ptrace frames; use standard-format size and no
+ * supervisor xstates:
+ */
+ update_regset_xstate_info(fpu_user_xstate_size, xfeatures_mask & ~XFEATURE_MASK_SUPERVISOR);
+
fpu__init_prepare_fx_sw_frame();
setup_init_fpu_buf();
setup_xstate_comp();
@@ -925,16 +931,16 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
if (!boot_cpu_has(X86_FEATURE_OSPKE))
return -EINVAL;
- /* Set the bits we need in PKRU */
+ /* Set the bits we need in PKRU: */
if (init_val & PKEY_DISABLE_ACCESS)
new_pkru_bits |= PKRU_AD_BIT;
if (init_val & PKEY_DISABLE_WRITE)
new_pkru_bits |= PKRU_WD_BIT;
- /* Shift the bits in to the correct place in PKRU for pkey. */
+ /* Shift the bits in to the correct place in PKRU for pkey: */
new_pkru_bits <<= pkey_shift;
- /* Locate old copy of the state in the xsave buffer */
+ /* Locate old copy of the state in the xsave buffer: */
old_pkru_state = get_xsave_addr(xsave, XFEATURE_MASK_PKRU);
/*
@@ -947,9 +953,10 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
else
new_pkru_state.pkru = old_pkru_state->pkru;
- /* mask off any old bits in place */
+ /* Mask off any old bits in place: */
new_pkru_state.pkru &= ~((PKRU_AD_BIT|PKRU_WD_BIT) << pkey_shift);
- /* Set the newly-requested bits */
+
+ /* Set the newly-requested bits: */
new_pkru_state.pkru |= new_pkru_bits;
/*
@@ -963,8 +970,168 @@ int arch_set_user_pkey_access(struct task_struct *tsk, int pkey,
*/
new_pkru_state.pad = 0;
- fpu__xfeature_set_state(XFEATURE_MASK_PKRU, &new_pkru_state,
- sizeof(new_pkru_state));
+ fpu__xfeature_set_state(XFEATURE_MASK_PKRU, &new_pkru_state, sizeof(new_pkru_state));
+
+ return 0;
+}
+
+/*
+ * This is similar to user_regset_copyout(), but will not add offset to
+ * the source data pointer or increment pos, count, kbuf, and ubuf.
+ */
+static inline int xstate_copyout(unsigned int pos, unsigned int count,
+ void *kbuf, void __user *ubuf,
+ const void *data, const int start_pos,
+ const int end_pos)
+{
+ if ((count == 0) || (pos < start_pos))
+ return 0;
+
+ if (end_pos < 0 || pos < end_pos) {
+ unsigned int copy = (end_pos < 0 ? count : min(count, end_pos - pos));
+
+ if (kbuf) {
+ memcpy(kbuf + pos, data, copy);
+ } else {
+ if (__copy_to_user(ubuf + pos, data, copy))
+ return -EFAULT;
+ }
+ }
+ return 0;
+}
+
+/*
+ * Convert from kernel XSAVES compacted format to standard format and copy
+ * to a ptrace buffer. It supports partial copy but pos always starts from
+ * zero. This is called from xstateregs_get() and there we check the CPU
+ * has XSAVES.
+ */
+int copyout_from_xsaves(unsigned int pos, unsigned int count, void *kbuf,
+ void __user *ubuf, struct xregs_state *xsave)
+{
+ unsigned int offset, size;
+ int ret, i;
+ struct xstate_header header;
+
+ /*
+ * Currently copy_regset_to_user() starts from pos 0:
+ */
+ if (unlikely(pos != 0))
+ return -EFAULT;
+
+ /*
+ * The destination is a ptrace buffer; we put in only user xstates:
+ */
+ memset(&header, 0, sizeof(header));
+ header.xfeatures = xsave->header.xfeatures;
+ header.xfeatures &= ~XFEATURE_MASK_SUPERVISOR;
+
+ /*
+ * Copy xregs_state->header:
+ */
+ offset = offsetof(struct xregs_state, header);
+ size = sizeof(header);
+
+ ret = xstate_copyout(offset, size, kbuf, ubuf, &header, 0, count);
+
+ if (ret)
+ return ret;
+
+ for (i = 0; i < XFEATURE_MAX; i++) {
+ /*
+ * Copy only in-use xstates:
+ */
+ if ((header.xfeatures >> i) & 1) {
+ void *src = __raw_xsave_addr(xsave, 1 << i);
+
+ offset = xstate_offsets[i];
+ size = xstate_sizes[i];
+
+ ret = xstate_copyout(offset, size, kbuf, ubuf, src, 0, count);
+
+ if (ret)
+ return ret;
+
+ if (offset + size >= count)
+ break;
+ }
+
+ }
+
+ /*
+ * Fill xsave->i387.sw_reserved value for ptrace frame:
+ */
+ offset = offsetof(struct fxregs_state, sw_reserved);
+ size = sizeof(xstate_fx_sw_bytes);
+
+ ret = xstate_copyout(offset, size, kbuf, ubuf, xstate_fx_sw_bytes, 0, count);
+
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+/*
+ * Convert from a ptrace standard-format buffer to kernel XSAVES format
+ * and copy to the target thread. This is called from xstateregs_set() and
+ * there we check the CPU has XSAVES and a whole standard-sized buffer
+ * exists.
+ */
+int copyin_to_xsaves(const void *kbuf, const void __user *ubuf,
+ struct xregs_state *xsave)
+{
+ unsigned int offset, size;
+ int i;
+ u64 xfeatures;
+ u64 allowed_features;
+
+ offset = offsetof(struct xregs_state, header);
+ size = sizeof(xfeatures);
+
+ if (kbuf) {
+ memcpy(&xfeatures, kbuf + offset, size);
+ } else {
+ if (__copy_from_user(&xfeatures, ubuf + offset, size))
+ return -EFAULT;
+ }
+
+ /*
+ * Reject if the user sets any disabled or supervisor features:
+ */
+ allowed_features = xfeatures_mask & ~XFEATURE_MASK_SUPERVISOR;
+
+ if (xfeatures & ~allowed_features)
+ return -EINVAL;
+
+ for (i = 0; i < XFEATURE_MAX; i++) {
+ u64 mask = ((u64)1 << i);
+
+ if (xfeatures & mask) {
+ void *dst = __raw_xsave_addr(xsave, 1 << i);
+
+ offset = xstate_offsets[i];
+ size = xstate_sizes[i];
+
+ if (kbuf) {
+ memcpy(dst, kbuf + offset, size);
+ } else {
+ if (__copy_from_user(dst, ubuf + offset, size))
+ return -EFAULT;
+ }
+ }
+ }
+
+ /*
+ * The state that came in from userspace was user-state only.
+ * Mask all the user states out of 'xfeatures':
+ */
+ xsave->header.xfeatures &= XFEATURE_MASK_SUPERVISOR;
+
+ /*
+ * Add back in the features that came in from userspace:
+ */
+ xsave->header.xfeatures |= xfeatures;
return 0;
}
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [tip:x86/fpu] x86/fpu/xstate: Fix XSTATE component offset print out
2016-06-17 20:07 ` [PATCH 4/5] x86/fpu/xstate: Fix XSTATE component offset print out Yu-cheng Yu
@ 2016-07-10 18:15 ` tip-bot for Yu-cheng Yu
0 siblings, 0 replies; 11+ messages in thread
From: tip-bot for Yu-cheng Yu @ 2016-07-10 18:15 UTC (permalink / raw)
To: linux-tip-commits
Cc: yu-cheng.yu, bp, tglx, dvlasenk, sai.praneeth.prakhya,
dave.hansen, quentin.casasnovas, oleg, linux-kernel, hpa, luto,
dave.hansen, fenghua.yu, torvalds, ravi.v.shankar, mingo, peterz,
brgerst, jpoimboe
Commit-ID: 996952e0148026ac0e512db5cad26e14f4267e8b
Gitweb: http://git.kernel.org/tip/996952e0148026ac0e512db5cad26e14f4267e8b
Author: Yu-cheng Yu <yu-cheng.yu@intel.com>
AuthorDate: Fri, 17 Jun 2016 13:07:18 -0700
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Sun, 10 Jul 2016 17:12:10 +0200
x86/fpu/xstate: Fix XSTATE component offset print out
Component offset print out was incorrect for XSAVES. Correct it and move
to a separate function.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/86602a8ac400626c6eca7125c3e15934866fc38e.1466179491.git.yu-cheng.yu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/fpu/xstate.c | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 56c0e70..09bac97 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -269,8 +269,6 @@ static void __init setup_xstate_features(void)
WARN_ONCE(last_good_offset > xstate_offsets[i],
"x86/fpu: misordered xstate at %d\n", last_good_offset);
last_good_offset = xstate_offsets[i];
-
- printk(KERN_INFO "x86/fpu: xstate_offset[%d]: %4d, xstate_sizes[%d]: %4d\n", i, ebx, i, eax);
}
}
@@ -374,6 +372,21 @@ static void __init setup_xstate_comp(void)
}
/*
+ * Print out xstate component offsets and sizes
+ */
+static void __init print_xstate_offset_size(void)
+{
+ int i;
+
+ for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
+ if (!xfeature_enabled(i))
+ continue;
+ pr_info("x86/fpu: xstate_offset[%d]: %4d, xstate_sizes[%d]: %4d\n",
+ i, xstate_comp_offsets[i], i, xstate_sizes[i]);
+ }
+}
+
+/*
* setup the xstate image representing the init state
*/
static void __init setup_init_fpu_buf(void)
@@ -707,6 +720,7 @@ void __init fpu__init_system_xstate(void)
fpu__init_prepare_fx_sw_frame();
setup_init_fpu_buf();
setup_xstate_comp();
+ print_xstate_offset_size();
pr_info("x86/fpu: Enabled xstate features 0x%llx, context size is %d bytes, using '%s' format.\n",
xfeatures_mask,
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [tip:x86/fpu] x86/fpu/xstate: Fix xstate_offsets, xstate_sizes for non-extended xstates
2016-06-17 20:07 ` [PATCH 5/5] x86/fpu/xstate: Fix xstate_offsets, xstate_sizes for non-extended xstates Yu-cheng Yu
@ 2016-07-10 18:15 ` tip-bot for Yu-cheng Yu
0 siblings, 0 replies; 11+ messages in thread
From: tip-bot for Yu-cheng Yu @ 2016-07-10 18:15 UTC (permalink / raw)
To: linux-tip-commits
Cc: linux-kernel, bp, mingo, brgerst, jpoimboe, dave.hansen,
fenghua.yu, ravi.v.shankar, dvlasenk, hpa, dave.hansen,
sai.praneeth.prakhya, yu-cheng.yu, torvalds, oleg, peterz, luto,
tglx, quentin.casasnovas
Commit-ID: ac73b27aea4eacdd7555f664d5fc6e1d4d1c8bf6
Gitweb: http://git.kernel.org/tip/ac73b27aea4eacdd7555f664d5fc6e1d4d1c8bf6
Author: Yu-cheng Yu <yu-cheng.yu@intel.com>
AuthorDate: Fri, 17 Jun 2016 13:07:19 -0700
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Sun, 10 Jul 2016 17:12:11 +0200
x86/fpu/xstate: Fix xstate_offsets, xstate_sizes for non-extended xstates
The arrays xstate_offsets[] and xstate_sizes[] record XSAVE standard-
format offsets and sizes. Values for non-extended state components
fpu and xmm's were not initialized or used. Ptrace format conversion
needs them. Fix it.
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/cf3ea36cf30e2a99e37da6483e65446d018ff0a7.1466179491.git.yu-cheng.yu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/kernel/fpu/xstate.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index 09bac97..f8d1aff 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -246,6 +246,15 @@ static void __init setup_xstate_features(void)
/* start at the beginnning of the "extended state" */
unsigned int last_good_offset = offsetof(struct xregs_state,
extended_state_area);
+ /*
+ * The FP xstates and SSE xstates are legacy states. They are always
+ * in the fixed offsets in the xsave area in either compacted form
+ * or standard form.
+ */
+ xstate_offsets[0] = 0;
+ xstate_sizes[0] = offsetof(struct fxregs_state, xmm_space);
+ xstate_offsets[1] = xstate_sizes[0];
+ xstate_sizes[1] = FIELD_SIZEOF(struct fxregs_state, xmm_space);
for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
if (!xfeature_enabled(i))
^ permalink raw reply related [flat|nested] 11+ messages in thread
end of thread, other threads:[~2016-07-10 18:18 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-06-17 20:07 [PATCH 0/5] x86/fpu/xstate: Fix XSAVES issues - Part 2 Yu-cheng Yu
2016-06-17 20:07 ` [PATCH 1/5] x86/fpu/xstate: Align xstate components according to CPUID Yu-cheng Yu
2016-07-10 18:14 ` [tip:x86/fpu] " tip-bot for Yu-cheng Yu
2016-06-17 20:07 ` [PATCH 2/5] x86/fpu/xstate: Fix supervisor xstate component offset Yu-cheng Yu
2016-07-10 18:14 ` [tip:x86/fpu] " tip-bot for Yu-cheng Yu
2016-06-17 20:07 ` [PATCH 3/5] x86/fpu/xstate: Fix PTRACE frames for XSAVES Yu-cheng Yu
2016-07-10 18:14 ` [tip:x86/fpu] " tip-bot for Yu-cheng Yu
2016-06-17 20:07 ` [PATCH 4/5] x86/fpu/xstate: Fix XSTATE component offset print out Yu-cheng Yu
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2016-06-17 20:07 ` [PATCH 5/5] x86/fpu/xstate: Fix xstate_offsets, xstate_sizes for non-extended xstates Yu-cheng Yu
2016-07-10 18:15 ` [tip:x86/fpu] " tip-bot for Yu-cheng Yu
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