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-rw-r--r--arch/powerpc/lib/sstep.c235
1 files changed, 106 insertions, 129 deletions
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 96283499664b..25ee04321870 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -193,7 +193,6 @@ static nokprobe_inline unsigned long max_align(unsigned long x)
return x & -x; /* isolates rightmost bit */
}
-
static nokprobe_inline unsigned long byterev_2(unsigned long x)
{
return ((x >> 8) & 0xff) | ((x & 0xff) << 8);
@@ -239,56 +238,69 @@ static nokprobe_inline int read_mem_aligned(unsigned long *dest,
return err;
}
-static nokprobe_inline int read_mem_unaligned(unsigned long *dest,
- unsigned long ea, int nb, struct pt_regs *regs)
+/*
+ * Copy from userspace to a buffer, using the largest possible
+ * aligned accesses, up to sizeof(long).
+ */
+static int nokprobe_inline copy_mem_in(u8 *dest, unsigned long ea, int nb)
{
- int err;
- unsigned long x, b, c;
-#ifdef __LITTLE_ENDIAN__
- int len = nb; /* save a copy of the length for byte reversal */
-#endif
+ int err = 0;
+ int c;
- /* 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);
+ switch (c) {
+ case 1:
+ err = __get_user(*dest, (unsigned char __user *) ea);
+ break;
+ case 2:
+ err = __get_user(*(u16 *)dest,
+ (unsigned short __user *) ea);
+ break;
+ case 4:
+ err = __get_user(*(u32 *)dest,
+ (unsigned int __user *) ea);
+ break;
+#ifdef __powerpc64__
+ case 8:
+ err = __get_user(*(unsigned long *)dest,
+ (unsigned long __user *) ea);
+ break;
+#endif
+ }
if (err)
return err;
- x = (x << (8 * c)) + b;
+ dest += c;
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;
}
+static nokprobe_inline int read_mem_unaligned(unsigned long *dest,
+ unsigned long ea, int nb,
+ struct pt_regs *regs)
+{
+ union {
+ unsigned long ul;
+ u8 b[sizeof(unsigned long)];
+ } u;
+ int i;
+ int err;
+
+ u.ul = 0;
+ i = IS_BE ? sizeof(unsigned long) - nb : 0;
+ err = copy_mem_in(&u.b[i], ea, nb);
+ if (!err)
+ *dest = u.ul;
+ return err;
+}
+
/*
* Read memory at address ea for nb bytes, return 0 for success
- * or -EFAULT if an error occurred.
+ * or -EFAULT if an error occurred. N.B. nb must be 1, 2, 4 or 8.
+ * If nb < sizeof(long), the result is right-justified on BE systems.
*/
static int read_mem(unsigned long *dest, unsigned long ea, int nb,
struct pt_regs *regs)
@@ -325,48 +337,64 @@ static nokprobe_inline int write_mem_aligned(unsigned long val,
return err;
}
-static nokprobe_inline int write_mem_unaligned(unsigned long val,
- unsigned long ea, int nb, struct pt_regs *regs)
+/*
+ * Copy from a buffer to userspace, using the largest possible
+ * aligned accesses, up to sizeof(long).
+ */
+static int nokprobe_inline copy_mem_out(u8 *dest, unsigned long ea, int nb)
{
- int err;
- unsigned long c;
+ int err = 0;
+ int 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);
+ switch (c) {
+ case 1:
+ err = __put_user(*dest, (unsigned char __user *) ea);
+ break;
+ case 2:
+ err = __put_user(*(u16 *)dest,
+ (unsigned short __user *) ea);
+ break;
+ case 4:
+ err = __put_user(*(u32 *)dest,
+ (unsigned int __user *) ea);
+ break;
+#ifdef __powerpc64__
+ case 8:
+ err = __put_user(*(unsigned long *)dest,
+ (unsigned long __user *) ea);
+ break;
+#endif
+ }
if (err)
return err;
+ dest += c;
ea += c;
}
return 0;
}
+static nokprobe_inline int write_mem_unaligned(unsigned long val,
+ unsigned long ea, int nb,
+ struct pt_regs *regs)
+{
+ union {
+ unsigned long ul;
+ u8 b[sizeof(unsigned long)];
+ } u;
+ int i;
+
+ u.ul = val;
+ i = IS_BE ? sizeof(unsigned long) - nb : 0;
+ return copy_mem_out(&u.b[i], ea, nb);
+}
+
/*
* Write memory at address ea for nb bytes, return 0 for success
- * or -EFAULT if an error occurred.
+ * or -EFAULT if an error occurred. N.B. nb must be 1, 2, 4 or 8.
*/
static int write_mem(unsigned long val, unsigned long ea, int nb,
struct pt_regs *regs)
@@ -389,40 +417,17 @@ static int do_fp_load(int rn, int (*func)(int, unsigned long),
struct pt_regs *regs)
{
int err;
- 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;
+ u8 buf[sizeof(double)] __attribute__((aligned(sizeof(double))));
if (!address_ok(regs, ea, nb))
return -EFAULT;
- if ((ea & 3) == 0)
- return (*func)(rn, ea);
- ptr = (unsigned long) &data.ul;
- if (sizeof(unsigned long) == 8 || nb == 4) {
- 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(&data.ul[0], ea, 4, regs);
- if (!err)
- err = read_mem_unaligned(&data.ul[1], ea + 4, 4, regs);
+ if (ea & 3) {
+ err = copy_mem_in(buf, ea, nb);
+ if (err)
+ return err;
+ ea = (unsigned long) buf;
}
- if (err)
- return err;
- return (*func)(rn, ptr);
+ return (*func)(rn, ea);
}
NOKPROBE_SYMBOL(do_fp_load);
@@ -431,43 +436,15 @@ static int do_fp_store(int rn, int (*func)(int, unsigned long),
struct pt_regs *regs)
{
int err;
- 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;
+ u8 buf[sizeof(double)] __attribute__((aligned(sizeof(double))));
if (!address_ok(regs, ea, nb))
return -EFAULT;
if ((ea & 3) == 0)
return (*func)(rn, ea);
- ptr = (unsigned long) &data.ul[0];
- if (sizeof(unsigned long) == 8 || nb == 4) {
- if (nb == 4)
- ptr = (unsigned long)&(data.single.word);
- err = (*func)(rn, ptr);
- if (err)
- return err;
- 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(data.ul[0], ea, 4, regs);
- if (!err)
- err = write_mem_unaligned(data.ul[1], ea + 4, 4, regs);
- }
+ err = (*func)(rn, (unsigned long) buf);
+ if (!err)
+ err = copy_mem_out(buf, ea, nb);
return err;
}
NOKPROBE_SYMBOL(do_fp_store);
@@ -2564,7 +2541,7 @@ int emulate_step(struct pt_regs *regs, unsigned int instr)
#endif
#ifdef CONFIG_VSX
case LOAD_VSX: {
- char mem[16];
+ u8 mem[16];
union vsx_reg buf;
unsigned long msrbit = MSR_VSX;
@@ -2577,7 +2554,7 @@ int emulate_step(struct pt_regs *regs, unsigned int instr)
if (!(regs->msr & msrbit))
return 0;
if (!address_ok(regs, ea, size) ||
- __copy_from_user(mem, (void __user *)ea, size))
+ copy_mem_in(mem, ea, size))
return 0;
emulate_vsx_load(&op, &buf, mem);
@@ -2639,7 +2616,7 @@ int emulate_step(struct pt_regs *regs, unsigned int instr)
#endif
#ifdef CONFIG_VSX
case STORE_VSX: {
- char mem[16];
+ u8 mem[16];
union vsx_reg buf;
unsigned long msrbit = MSR_VSX;
@@ -2656,7 +2633,7 @@ int emulate_step(struct pt_regs *regs, unsigned int instr)
store_vsrn(op.reg, &buf);
emulate_vsx_store(&op, &buf, mem);
- if (__copy_to_user((void __user *)ea, mem, size))
+ if (copy_mem_out(mem, ea, size))
return 0;
goto ldst_done;
}
generated by cgit v1.2.3-55-g7522 (git 2.39.0) at 2024-07-23 16:09:41 +0200