um: finish conversion to mcontext_t

now we don't mix host and guest signal frame layouts anymore; moreover,
we don't need host's struct sigcontext at all.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>

3 files changed, 35 insertions, 4 deletions

diff --git a/arch/um/os-Linux/signal.c b/arch/um/os-Linux/signal.c
index 07d9905e44e..9f2c2228f7a 100644
--- a/arch/um/os-Linux/signal.c
+++ b/arch/um/os-Linux/signal.c
@@ -14,7 +14,7 @@
 #include "os.h"
 #include "process.h"
 #include "sysdep/barrier.h"
-#include "sysdep/sigcontext.h"
+#include "sysdep/mcontext.h"
 
 void (*sig_info[NSIG])(int, struct uml_pt_regs *) = {
         [SIGTRAP]       = relay_signal,
@@ -34,7 +34,7 @@ static void sig_handler_common(int sig, mcontext_t *mc)
         r.is_user = 0;
         if (sig == SIGSEGV) {
                 /* For segfaults, we want the data from the sigcontext. */
-                copy_sc(&r, (struct sigcontext *)mc);
+                get_regs_from_mc(&r, mc);
                 GET_FAULTINFO_FROM_MC(r.faultinfo, mc);
         }
 
@@ -84,7 +84,7 @@ static void real_alarm_handler(mcontext_t *mc)
         struct uml_pt_regs regs;
 
         if (mc != NULL)
-                copy_sc(&regs, (struct sigcontext *)mc);
+                get_regs_from_mc(&regs, mc);
         regs.is_user = 0;
         unblock_signals();
         timer_handler(SIGVTALRM, &regs);
diff --git a/arch/um/os-Linux/sys-x86/Makefile b/arch/um/os-Linux/sys-x86/Makefile
index 22cc5073c02..253bfb8cb70 100644
--- a/arch/um/os-Linux/sys-x86/Makefile
+++ b/arch/um/os-Linux/sys-x86/Makefile
@@ -3,7 +3,7 @@
 # Licensed under the GPL
 #
 
-obj-y = registers.o task_size.o
+obj-y = registers.o task_size.o mcontext.o
 
 obj-$(CONFIG_X86_32) += tls.o
 obj-$(CONFIG_64BIT) += prctl.o
diff --git a/arch/um/os-Linux/sys-x86/mcontext.c b/arch/um/os-Linux/sys-x86/mcontext.c
new file mode 100644
index 00000000000..1d33d72c628
--- /dev/null
+++ b/arch/um/os-Linux/sys-x86/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
+}