1 files changed, 20 insertions, 18 deletions

diff --git a/include/asm-powerpc/elf.h b/include/asm-powerpc/elf.h
index 5b9e3f41d649..8925c2813667 100644
--- a/include/asm-powerpc/elf.h
+++ b/include/asm-powerpc/elf.h
@@ -101,6 +101,7 @@ typedef elf_greg_t64 elf_gregset_t64[ELF_NGREG];
 
 typedef unsigned int elf_greg_t32;
 typedef elf_greg_t32 elf_gregset_t32[ELF_NGREG];
+typedef elf_gregset_t32 compat_elf_gregset_t;
 
 /*
  * ELF_ARCH, CLASS, and DATA are used to set parameters in the core dumps.
@@ -175,26 +176,27 @@ typedef elf_vrreg_t elf_vrregset_t32[ELF_NVRREG32];
 
 #define ELF_ET_DYN_BASE         (0x20000000)
 
-/* Common routine for both 32-bit and 64-bit processes */
+/*
+ * Our registers are always unsigned longs, whether we're a 32 bit
+ * process or 64 bit, on either a 64 bit or 32 bit kernel.
+ *
+ * This macro relies on elf_regs[i] having the right type to truncate to,
+ * either u32 or u64.  It defines the body of the elf_core_copy_regs
+ * function, either the native one with elf_gregset_t elf_regs or
+ * the 32-bit one with elf_gregset_t32 elf_regs.
+ */
+#define PPC_ELF_CORE_COPY_REGS(elf_regs, regs) \
+        int i, nregs = min(sizeof(*regs) / sizeof(unsigned long), \
+                           (size_t)ELF_NGREG);                    \
+        for (i = 0; i < nregs; i++) \
+                elf_regs[i] = ((unsigned long *) regs)[i]; \
+        memset(&elf_regs[i], 0, (ELF_NGREG - i) * sizeof(elf_regs[0]))
+
+/* Common routine for both 32-bit and 64-bit native processes */
 static inline void ppc_elf_core_copy_regs(elf_gregset_t elf_regs,
-                                            struct pt_regs *regs)
+                                          struct pt_regs *regs)
 {
-        int i, nregs;
-
-        memset((void *)elf_regs, 0, sizeof(elf_gregset_t));
-
-        /* Our registers are always unsigned longs, whether we're a 32 bit
-         * process or 64 bit, on either a 64 bit or 32 bit kernel.
-         * Don't use ELF_GREG_TYPE here. */
-        nregs = sizeof(struct pt_regs) / sizeof(unsigned long);
-        if (nregs > ELF_NGREG)
-                nregs = ELF_NGREG;
-
-        for (i = 0; i < nregs; i++) {
-                /* This will correctly truncate 64 bit registers to 32 bits
-                 * for a 32 bit process on a 64 bit kernel. */
-                elf_regs[i] = (elf_greg_t)((ELF_GREG_TYPE *)regs)[i];
-        }
+        PPC_ELF_CORE_COPY_REGS(elf_regs, regs);
 }
 #define ELF_CORE_COPY_REGS(gregs, regs) ppc_elf_core_copy_regs(gregs, regs);