// SPDX-License-Identifier: GPL-2.0
-#include <sys/ucontext.h>
#define __FRAME_OFFSETS
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <sys/ucontext.h>
#include <asm/ptrace.h>
+#include <asm/sigcontext.h>
#include <sysdep/ptrace.h>
#include <sysdep/mcontext.h>
#include <arch.h>
COPY2(UESP, ESP); /* sic */
COPY(EBX); COPY(EDX); COPY(ECX); COPY(EAX);
COPY(EIP); COPY_SEG_CPL3(CS); COPY(EFL); COPY_SEG_CPL3(SS);
+#undef COPY2
+#undef COPY
+#undef COPY_SEG
+#undef COPY_SEG_CPL3
#else
#define COPY2(X,Y) regs->gp[X/sizeof(unsigned long)] = mc->gregs[REG_##Y]
#define COPY(X) regs->gp[X/sizeof(unsigned long)] = mc->gregs[REG_##X]
COPY2(EFLAGS, EFL);
COPY2(CS, CSGSFS);
regs->gp[SS / sizeof(unsigned long)] = mc->gregs[REG_CSGSFS] >> 48;
+#undef COPY2
+#undef COPY
#endif
}
mc->gregs[REG_RIP] = (unsigned long)target;
#endif
}
+
+/* Same thing, but the copy macros are turned around. */
+void get_mc_from_regs(struct uml_pt_regs *regs, mcontext_t *mc, int single_stepping)
+{
+#ifdef __i386__
+#define COPY2(X,Y) mc->gregs[REG_##Y] = regs->gp[X]
+#define COPY(X) mc->gregs[REG_##X] = regs->gp[X]
+#define COPY_SEG(X) mc->gregs[REG_##X] = regs->gp[X] & 0xffff;
+#define COPY_SEG_CPL3(X) mc->gregs[REG_##X] = (regs->gp[X] & 0xffff) | 3;
+ COPY_SEG(GS); COPY_SEG(FS); COPY_SEG(ES); COPY_SEG(DS);
+ COPY(EDI); COPY(ESI); COPY(EBP);
+ COPY2(UESP, ESP); /* sic */
+ COPY(EBX); COPY(EDX); COPY(ECX); COPY(EAX);
+ COPY(EIP); COPY_SEG_CPL3(CS); COPY(EFL); COPY_SEG_CPL3(SS);
+#else
+#define COPY2(X,Y) mc->gregs[REG_##Y] = regs->gp[X/sizeof(unsigned long)]
+#define COPY(X) mc->gregs[REG_##X] = regs->gp[X/sizeof(unsigned long)]
+ COPY(R8); COPY(R9); COPY(R10); COPY(R11);
+ COPY(R12); COPY(R13); COPY(R14); COPY(R15);
+ COPY(RDI); COPY(RSI); COPY(RBP); COPY(RBX);
+ COPY(RDX); COPY(RAX); COPY(RCX); COPY(RSP);
+ COPY(RIP);
+ COPY2(EFLAGS, EFL);
+ mc->gregs[REG_CSGSFS] = mc->gregs[REG_CSGSFS] & 0xffffffffffffl;
+ mc->gregs[REG_CSGSFS] |= (regs->gp[SS / sizeof(unsigned long)] & 0xffff) << 48;
+#endif
+
+ if (single_stepping)
+ mc->gregs[REG_EFL] |= X86_EFLAGS_TF;
+ else
+ mc->gregs[REG_EFL] &= ~X86_EFLAGS_TF;
+}
+
+#ifdef CONFIG_X86_32
+struct _xstate_64 {
+ struct _fpstate_64 fpstate;
+ struct _header xstate_hdr;
+ struct _ymmh_state ymmh;
+ /* New processor state extensions go here: */
+};
+
+/* Not quite the right structures as these contain more information */
+int um_i387_from_fxsr(struct _fpstate_32 *i387,
+ const struct _fpstate_64 *fxsave);
+int um_fxsr_from_i387(struct _fpstate_64 *fxsave,
+ const struct _fpstate_32 *from);
+#else
+#define _xstate_64 _xstate
+#endif
+
+static struct _fpstate *get_fpstate(struct stub_data *data,
+ mcontext_t *mcontext,
+ int *fp_size)
+{
+ struct _fpstate *res;
+
+ /* Assume floating point registers are on the same page */
+ res = (void *)(((unsigned long)mcontext->fpregs &
+ (UM_KERN_PAGE_SIZE - 1)) +
+ (unsigned long)&data->sigstack[0]);
+
+ if ((void *)res + sizeof(struct _fpstate) >
+ (void *)data->sigstack + sizeof(data->sigstack))
+ return NULL;
+
+ if (res->sw_reserved.magic1 != FP_XSTATE_MAGIC1) {
+ *fp_size = sizeof(struct _fpstate);
+ } else {
+ char *magic2_addr;
+
+ magic2_addr = (void *)res;
+ magic2_addr += res->sw_reserved.extended_size;
+ magic2_addr -= FP_XSTATE_MAGIC2_SIZE;
+
+ /* We still need to be within our stack */
+ if ((void *)magic2_addr >
+ (void *)data->sigstack + sizeof(data->sigstack))
+ return NULL;
+
+ /* If we do not read MAGIC2, then we did something wrong */
+ if (*(__u32 *)magic2_addr != FP_XSTATE_MAGIC2)
+ return NULL;
+
+ /* Remove MAGIC2 from the size, we do not save/restore it */
+ *fp_size = res->sw_reserved.extended_size -
+ FP_XSTATE_MAGIC2_SIZE;
+ }
+
+ return res;
+}
+
+int get_stub_state(struct uml_pt_regs *regs, struct stub_data *data,
+ unsigned long *fp_size_out)
+{
+ mcontext_t *mcontext;
+ struct _fpstate *fpstate_stub;
+ struct _xstate_64 *xstate_stub;
+ int fp_size, xstate_size;
+
+ /* mctx_offset is verified by wait_stub_done_seccomp */
+ mcontext = (void *)&data->sigstack[data->mctx_offset];
+
+ get_regs_from_mc(regs, mcontext);
+
+ fpstate_stub = get_fpstate(data, mcontext, &fp_size);
+ if (!fpstate_stub)
+ return -EINVAL;
+
+#ifdef CONFIG_X86_32
+ xstate_stub = (void *)&fpstate_stub->_fxsr_env;
+ xstate_size = fp_size - offsetof(struct _fpstate_32, _fxsr_env);
+#else
+ xstate_stub = (void *)fpstate_stub;
+ xstate_size = fp_size;
+#endif
+
+ if (fp_size_out)
+ *fp_size_out = xstate_size;
+
+ if (xstate_size > host_fp_size)
+ return -ENOSPC;
+
+ memcpy(®s->fp, xstate_stub, xstate_size);
+
+ /* We do not need to read the x86_64 FS_BASE/GS_BASE registers as
+ * we do not permit userspace to set them directly.
+ */
+
+#ifdef CONFIG_X86_32
+ /* Read the i387 legacy FP registers */
+ if (um_fxsr_from_i387((void *)®s->fp, fpstate_stub))
+ return -EINVAL;
+#endif
+
+ return 0;
+}
+
+/* Copied because we cannot include regset.h here. */
+struct task_struct;
+struct user_regset;
+struct membuf {
+ void *p;
+ size_t left;
+};
+
+int fpregs_legacy_get(struct task_struct *target,
+ const struct user_regset *regset,
+ struct membuf to);
+
+int set_stub_state(struct uml_pt_regs *regs, struct stub_data *data,
+ int single_stepping)
+{
+ mcontext_t *mcontext;
+ struct _fpstate *fpstate_stub;
+ struct _xstate_64 *xstate_stub;
+ int fp_size, xstate_size;
+
+ /* mctx_offset is verified by wait_stub_done_seccomp */
+ mcontext = (void *)&data->sigstack[data->mctx_offset];
+
+ if ((unsigned long)mcontext < (unsigned long)data->sigstack ||
+ (unsigned long)mcontext >
+ (unsigned long) data->sigstack +
+ sizeof(data->sigstack) - sizeof(*mcontext))
+ return -EINVAL;
+
+ get_mc_from_regs(regs, mcontext, single_stepping);
+
+ fpstate_stub = get_fpstate(data, mcontext, &fp_size);
+ if (!fpstate_stub)
+ return -EINVAL;
+
+#ifdef CONFIG_X86_32
+ xstate_stub = (void *)&fpstate_stub->_fxsr_env;
+ xstate_size = fp_size - offsetof(struct _fpstate_32, _fxsr_env);
+#else
+ xstate_stub = (void *)fpstate_stub;
+ xstate_size = fp_size;
+#endif
+
+ memcpy(fpstate_stub, ®s->fp, fp_size);
+
+#ifdef __i386__
+ /*
+ * On x86, the GDT entries are updated by arch_set_tls.
+ */
+
+ /* Store the i387 legacy FP registers which the host will use */
+ if (um_i387_from_fxsr(fpstate_stub, (void *)®s->fp))
+ return -EINVAL;
+#else
+ /*
+ * On x86_64, we need to sync the FS_BASE/GS_BASE registers using the
+ * arch specific data.
+ */
+ if (data->arch_data.fs_base != regs->gp[FS_BASE / sizeof(unsigned long)]) {
+ data->arch_data.fs_base = regs->gp[FS_BASE / sizeof(unsigned long)];
+ data->arch_data.sync |= STUB_SYNC_FS_BASE;
+ }
+ if (data->arch_data.gs_base != regs->gp[GS_BASE / sizeof(unsigned long)]) {
+ data->arch_data.gs_base = regs->gp[GS_BASE / sizeof(unsigned long)];
+ data->arch_data.sync |= STUB_SYNC_GS_BASE;
+ }
+#endif
+
+ return 0;
+}
return tmp;
}
-static inline unsigned long twd_fxsr_to_i387(struct user_fxsr_struct *fxsave)
+static inline unsigned long
+twd_fxsr_to_i387(const struct user_fxsr_struct *fxsave)
{
struct _fpxreg *st = NULL;
unsigned long twd = (unsigned long) fxsave->twd;
return ret;
}
-/* Get/set the old 32bit i387 registers (pre-FPX) */
-static int fpregs_legacy_get(struct task_struct *target,
- const struct user_regset *regset,
- struct membuf to)
+/*
+ * Get/set the old 32bit i387 registers (pre-FPX)
+ *
+ * We provide simple wrappers for mcontext.c, they are only defined locally
+ * because mcontext.c is userspace facing and needs to a different definition
+ * of the structures.
+ */
+static int _um_i387_from_fxsr(struct membuf to,
+ const struct user_fxsr_struct *fxsave)
{
- struct user_fxsr_struct *fxsave = (void *)target->thread.regs.regs.fp;
int i;
membuf_store(&to, (unsigned long)fxsave->cwd | 0xffff0000ul);
return 0;
}
-static int fpregs_legacy_set(struct task_struct *target,
+int um_i387_from_fxsr(struct user_i387_struct *i387,
+ const struct user_fxsr_struct *fxsave);
+
+int um_i387_from_fxsr(struct user_i387_struct *i387,
+ const struct user_fxsr_struct *fxsave)
+{
+ struct membuf to = {
+ .p = i387,
+ .left = sizeof(*i387),
+ };
+
+ return _um_i387_from_fxsr(to, fxsave);
+}
+
+static int fpregs_legacy_get(struct task_struct *target,
const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- const void *kbuf, const void __user *ubuf)
+ struct membuf to)
{
struct user_fxsr_struct *fxsave = (void *)target->thread.regs.regs.fp;
- const struct user_i387_struct *from;
- struct user_i387_struct buf;
- int i;
- if (ubuf) {
- if (copy_from_user(&buf, ubuf, sizeof(buf)))
- return -EFAULT;
- from = &buf;
- } else {
- from = kbuf;
- }
+ return _um_i387_from_fxsr(to, fxsave);
+}
+
+int um_fxsr_from_i387(struct user_fxsr_struct *fxsave,
+ const struct user_i387_struct *from);
+
+int um_fxsr_from_i387(struct user_fxsr_struct *fxsave,
+ const struct user_i387_struct *from)
+{
+ int i;
fxsave->cwd = (unsigned short)(from->cwd & 0xffff);
fxsave->swd = (unsigned short)(from->swd & 0xffff);
return 0;
}
+
+static int fpregs_legacy_set(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ struct user_fxsr_struct *fxsave = (void *)target->thread.regs.regs.fp;
+ const struct user_i387_struct *from;
+ struct user_i387_struct buf;
+
+ if (ubuf) {
+ if (copy_from_user(&buf, ubuf, sizeof(buf)))
+ return -EFAULT;
+ from = &buf;
+ } else {
+ from = kbuf;
+ }
+
+ return um_fxsr_from_i387(fxsave, &buf);
+}
#endif
static int genregs_get(struct task_struct *target,
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