1 files changed, 85 insertions, 12 deletions

diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index b1faa1593c90..c0511c27a733 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -212,11 +212,19 @@ static int __kprobes read_mem_unaligned(unsigned long *dest, unsigned long ea,
 {
         int err;
         unsigned long x, b, c;
+#ifdef __LITTLE_ENDIAN__
+        int len = nb; /* save a copy of the length for byte reversal */
+#endif
 
         /* unaligned, do this in pieces */
         x = 0;
         for (; nb > 0; nb -= c) {
+#ifdef __LITTLE_ENDIAN__
+                c = 1;
+#endif
+#ifdef __BIG_ENDIAN__
                 c = max_align(ea);
+#endif
                 if (c > nb)
                         c = max_align(nb);
                 err = read_mem_aligned(&b, ea, c);
@@ -225,7 +233,24 @@ static int __kprobes read_mem_unaligned(unsigned long *dest, unsigned long ea,
                 x = (x << (8 * c)) + b;
                 ea += c;
         }
+#ifdef __LITTLE_ENDIAN__
+        switch (len) {
+        case 2:
+                *dest = byterev_2(x);
+                break;
+        case 4:
+                *dest = byterev_4(x);
+                break;
+#ifdef __powerpc64__
+        case 8:
+                *dest = byterev_8(x);
+                break;
+#endif
+        }
+#endif
+#ifdef __BIG_ENDIAN__
         *dest = x;
+#endif
         return 0;
 }
 
@@ -273,9 +298,29 @@ static int __kprobes write_mem_unaligned(unsigned long val, unsigned long ea,
         int err;
         unsigned long c;
 
+#ifdef __LITTLE_ENDIAN__
+        switch (nb) {
+        case 2:
+                val = byterev_2(val);
+                break;
+        case 4:
+                val = byterev_4(val);
+                break;
+#ifdef __powerpc64__
+        case 8:
+                val = byterev_8(val);
+                break;
+#endif
+        }
+#endif
         /* unaligned or little-endian, do this in pieces */
         for (; nb > 0; nb -= c) {
+#ifdef __LITTLE_ENDIAN__
+                c = 1;
+#endif
+#ifdef __BIG_ENDIAN__
                 c = max_align(ea);
+#endif
                 if (c > nb)
                         c = max_align(nb);
                 err = write_mem_aligned(val >> (nb - c) * 8, ea, c);
@@ -310,22 +355,36 @@ static int __kprobes do_fp_load(int rn, int (*func)(int, unsigned long),
                                 struct pt_regs *regs)
 {
         int err;
-        unsigned long val[sizeof(double) / sizeof(long)];
+        union {
+                double dbl;
+                unsigned long ul[2];
+                struct {
+#ifdef __BIG_ENDIAN__
+                        unsigned _pad_;
+                        unsigned word;
+#endif
+#ifdef __LITTLE_ENDIAN__
+                        unsigned word;
+                        unsigned _pad_;
+#endif
+                } single;
+        } data;
         unsigned long ptr;
 
         if (!address_ok(regs, ea, nb))
                 return -EFAULT;
         if ((ea & 3) == 0)
                 return (*func)(rn, ea);
-        ptr = (unsigned long) &val[0];
+        ptr = (unsigned long) &data.ul;
         if (sizeof(unsigned long) == 8 || nb == 4) {
-                err = read_mem_unaligned(&val[0], ea, nb, regs);
-                ptr += sizeof(unsigned long) - nb;
+                err = read_mem_unaligned(&data.ul[0], ea, nb, regs);
+                if (nb == 4)
+                        ptr = (unsigned long)&(data.single.word);
         } else {
                 /* reading a double on 32-bit */
-                err = read_mem_unaligned(&val[0], ea, 4, regs);
+                err = read_mem_unaligned(&data.ul[0], ea, 4, regs);
                 if (!err)
-                        err = read_mem_unaligned(&val[1], ea + 4, 4, regs);
+                        err = read_mem_unaligned(&data.ul[1], ea + 4, 4, regs);
         }
         if (err)
                 return err;
@@ -337,28 +396,42 @@ static int __kprobes do_fp_store(int rn, int (*func)(int, unsigned long),
                                  struct pt_regs *regs)
 {
         int err;
-        unsigned long val[sizeof(double) / sizeof(long)];
+        union {
+                double dbl;
+                unsigned long ul[2];
+                struct {
+#ifdef __BIG_ENDIAN__
+                        unsigned _pad_;
+                        unsigned word;
+#endif
+#ifdef __LITTLE_ENDIAN__
+                        unsigned word;
+                        unsigned _pad_;
+#endif
+                } single;
+        } data;
         unsigned long ptr;
 
         if (!address_ok(regs, ea, nb))
                 return -EFAULT;
         if ((ea & 3) == 0)
                 return (*func)(rn, ea);
-        ptr = (unsigned long) &val[0];
+        ptr = (unsigned long) &data.ul[0];
         if (sizeof(unsigned long) == 8 || nb == 4) {
-                ptr += sizeof(unsigned long) - nb;
+                if (nb == 4)
+                        ptr = (unsigned long)&(data.single.word);
                 err = (*func)(rn, ptr);
                 if (err)
                         return err;
-                err = write_mem_unaligned(val[0], ea, nb, regs);
+                err = write_mem_unaligned(data.ul[0], ea, nb, regs);
         } else {
                 /* writing a double on 32-bit */
                 err = (*func)(rn, ptr);
                 if (err)
                         return err;
-                err = write_mem_unaligned(val[0], ea, 4, regs);
+                err = write_mem_unaligned(data.ul[0], ea, 4, regs);
                 if (!err)
-                        err = write_mem_unaligned(val[1], ea + 4, 4, regs);
+                        err = write_mem_unaligned(data.ul[1], ea + 4, 4, regs);
         }
         return err;
 }