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Diffstat (limited to 'arch/x86/kernel/fpu/xstate.c')
-rw-r--r--arch/x86/kernel/fpu/xstate.c164
1 files changed, 27 insertions, 137 deletions
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index be2a68a09d19..7a2bf884fede 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -1014,32 +1014,20 @@ static inline bool xfeatures_mxcsr_quirk(u64 xfeatures)
return true;
}
-static void fill_gap(unsigned to, void **kbuf, unsigned *pos, unsigned *count)
+static void fill_gap(struct membuf *to, unsigned *last, unsigned offset)
{
- if (*pos < to) {
- unsigned size = to - *pos;
-
- if (size > *count)
- size = *count;
- memcpy(*kbuf, (void *)&init_fpstate.xsave + *pos, size);
- *kbuf += size;
- *pos += size;
- *count -= size;
- }
+ if (*last >= offset)
+ return;
+ membuf_write(to, (void *)&init_fpstate.xsave + *last, offset - *last);
+ *last = offset;
}
-static void copy_part(unsigned offset, unsigned size, void *from,
- void **kbuf, unsigned *pos, unsigned *count)
+static void copy_part(struct membuf *to, unsigned *last, unsigned offset,
+ unsigned size, void *from)
{
- fill_gap(offset, kbuf, pos, count);
- if (size > *count)
- size = *count;
- if (size) {
- memcpy(*kbuf, from, size);
- *kbuf += size;
- *pos += size;
- *count -= size;
- }
+ fill_gap(to, last, offset);
+ membuf_write(to, from, size);
+ *last = offset + size;
}
/*
@@ -1049,20 +1037,15 @@ static void copy_part(unsigned offset, unsigned size, void *from,
* 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 copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int offset_start, unsigned int size_total)
+void copy_xstate_to_kernel(struct membuf to, struct xregs_state *xsave)
{
struct xstate_header header;
const unsigned off_mxcsr = offsetof(struct fxregs_state, mxcsr);
- unsigned count = size_total;
+ unsigned size = to.left;
+ unsigned last = 0;
int i;
/*
- * Currently copy_regset_to_user() starts from pos 0:
- */
- if (unlikely(offset_start != 0))
- return -EFAULT;
-
- /*
* The destination is a ptrace buffer; we put in only user xstates:
*/
memset(&header, 0, sizeof(header));
@@ -1070,27 +1053,26 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int of
header.xfeatures &= xfeatures_mask_user();
if (header.xfeatures & XFEATURE_MASK_FP)
- copy_part(0, off_mxcsr,
- &xsave->i387, &kbuf, &offset_start, &count);
+ copy_part(&to, &last, 0, off_mxcsr, &xsave->i387);
if (header.xfeatures & (XFEATURE_MASK_SSE | XFEATURE_MASK_YMM))
- copy_part(off_mxcsr, MXCSR_AND_FLAGS_SIZE,
- &xsave->i387.mxcsr, &kbuf, &offset_start, &count);
+ copy_part(&to, &last, off_mxcsr,
+ MXCSR_AND_FLAGS_SIZE, &xsave->i387.mxcsr);
if (header.xfeatures & XFEATURE_MASK_FP)
- copy_part(offsetof(struct fxregs_state, st_space), 128,
- &xsave->i387.st_space, &kbuf, &offset_start, &count);
+ copy_part(&to, &last, offsetof(struct fxregs_state, st_space),
+ 128, &xsave->i387.st_space);
if (header.xfeatures & XFEATURE_MASK_SSE)
- copy_part(xstate_offsets[XFEATURE_SSE], 256,
- &xsave->i387.xmm_space, &kbuf, &offset_start, &count);
+ copy_part(&to, &last, xstate_offsets[XFEATURE_SSE],
+ 256, &xsave->i387.xmm_space);
/*
* Fill xsave->i387.sw_reserved value for ptrace frame:
*/
- copy_part(offsetof(struct fxregs_state, sw_reserved), 48,
- xstate_fx_sw_bytes, &kbuf, &offset_start, &count);
+ copy_part(&to, &last, offsetof(struct fxregs_state, sw_reserved),
+ 48, xstate_fx_sw_bytes);
/*
* Copy xregs_state->header:
*/
- copy_part(offsetof(struct xregs_state, header), sizeof(header),
- &header, &kbuf, &offset_start, &count);
+ copy_part(&to, &last, offsetof(struct xregs_state, header),
+ sizeof(header), &header);
for (i = FIRST_EXTENDED_XFEATURE; i < XFEATURE_MAX; i++) {
/*
@@ -1099,104 +1081,12 @@ int copy_xstate_to_kernel(void *kbuf, struct xregs_state *xsave, unsigned int of
if ((header.xfeatures >> i) & 1) {
void *src = __raw_xsave_addr(xsave, i);
- copy_part(xstate_offsets[i], xstate_sizes[i],
- src, &kbuf, &offset_start, &count);
+ copy_part(&to, &last, xstate_offsets[i],
+ xstate_sizes[i], src);
}
}
- fill_gap(size_total, &kbuf, &offset_start, &count);
-
- return 0;
-}
-
-static inline int
-__copy_xstate_to_user(void __user *ubuf, const void *data, unsigned int offset, unsigned int size, unsigned int size_total)
-{
- if (!size)
- return 0;
-
- if (offset < size_total) {
- unsigned int copy = min(size, size_total - offset);
-
- if (__copy_to_user(ubuf + offset, data, copy))
- return -EFAULT;
- }
- return 0;
-}
-
-/*
- * Convert from kernel XSAVES compacted format to standard format and copy
- * to a user-space 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 copy_xstate_to_user(void __user *ubuf, struct xregs_state *xsave, unsigned int offset_start, unsigned int size_total)
-{
- unsigned int offset, size;
- int ret, i;
- struct xstate_header header;
-
- /*
- * Currently copy_regset_to_user() starts from pos 0:
- */
- if (unlikely(offset_start != 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 &= xfeatures_mask_user();
-
- /*
- * Copy xregs_state->header:
- */
- offset = offsetof(struct xregs_state, header);
- size = sizeof(header);
-
- ret = __copy_xstate_to_user(ubuf, &header, offset, size, size_total);
- 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, i);
-
- offset = xstate_offsets[i];
- size = xstate_sizes[i];
-
- /* The next component has to fit fully into the output buffer: */
- if (offset + size > size_total)
- break;
-
- ret = __copy_xstate_to_user(ubuf, src, offset, size, size_total);
- if (ret)
- return ret;
- }
-
- }
-
- if (xfeatures_mxcsr_quirk(header.xfeatures)) {
- offset = offsetof(struct fxregs_state, mxcsr);
- size = MXCSR_AND_FLAGS_SIZE;
- __copy_xstate_to_user(ubuf, &xsave->i387.mxcsr, offset, size, size_total);
- }
-
- /*
- * Fill xsave->i387.sw_reserved value for ptrace frame:
- */
- offset = offsetof(struct fxregs_state, sw_reserved);
- size = sizeof(xstate_fx_sw_bytes);
-
- ret = __copy_xstate_to_user(ubuf, xstate_fx_sw_bytes, offset, size, size_total);
- if (ret)
- return ret;
-
- return 0;
+ fill_gap(&to, &last, size);
}
/*