1 files changed, 31 insertions, 0 deletions

diff --git a/arch/x86/um/os-Linux/mcontext.c b/arch/x86/um/os-Linux/mcontext.c
new file mode 100644
index 000000000000..1d33d72c6284
--- /dev/null
+++ b/arch/x86/um/os-Linux/mcontext.c
@@ -0,0 +1,31 @@
+#include <sys/ucontext.h>
+#define __FRAME_OFFSETS
+#include <asm/ptrace.h>
+#include <sysdep/ptrace.h>
+
+void get_regs_from_mc(struct uml_pt_regs *regs, mcontext_t *mc)
+{
+#ifdef __i386__
+#define COPY2(X,Y) regs->gp[X] = mc->gregs[REG_##Y]
+#define COPY(X) regs->gp[X] = mc->gregs[REG_##X]
+#define COPY_SEG(X) regs->gp[X] = mc->gregs[REG_##X] & 0xffff;
+#define COPY_SEG_CPL3(X) regs->gp[X] = (mc->gregs[REG_##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) regs->gp[X/sizeof(unsigned long)] = mc->gregs[REG_##Y]
+#define COPY(X) regs->gp[X/sizeof(unsigned long)] = mc->gregs[REG_##X]
+        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);
+        COPY2(CS, CSGSFS);
+        regs->gp[CS / sizeof(unsigned long)] &= 0xffff;
+        regs->gp[CS / sizeof(unsigned long)] |= 3;
+#endif
+}