powerpc64le: ROP Changes for strncpy/ppc-mount

Add ROP protect instructions to strncpy and ppc-mount functions.
Modify FRAME_MIN_SIZE to 48 bytes for ELFv2 to reserve additional
16 bytes for ROP save slot and padding.

Signed-off-by: Sachin Monga <smonga@linux.ibm.com>
Reviewed-by: Peter Bergner <bergner@linux.ibm.com>

diff --git a/sysdeps/powerpc/powerpc64/le/power9/strncpy.S b/sysdeps/powerpc/powerpc64/le/power9/strncpy.S
index 58139ad9e875011d68aa6a89c9b29bf3af304f3f..a3c32204143cf09b26e97ef2c528d8dda8f75e7b 100644 (file)
--- a/sysdeps/powerpc/powerpc64/le/power9/strncpy.S
+++ b/sysdeps/powerpc/powerpc64/le/power9/strncpy.S
@@ -365,8 +365,8 @@ L(zero_padding_end):
 
        .align  4
 L(zero_padding_memset):
-       std     r30,-8(r1)   /* Save r30 on the stack.  */
-       cfi_offset(r30, -8)
+       std     r30,-16(r1)  /* Save r30 on the stack.  */
+       cfi_offset(r30, -16)
        mr      r30,r3       /* Save the return value of strncpy.  */
        /* Prepare the call to memset.  */
        mr      r3,r11       /* Pointer to the area to be zero-filled.  */
@@ -380,6 +380,9 @@ L(zero_padding_memset):
        mflr    r0
        std     r0,16(r1)
 
+#ifdef __ROP_PROTECT__
+       hashst  0,FRAME_ROP_SAVE(r1)
+#endif
        /* Create the stack frame.  */
        stdu    r1,-FRAMESIZE(r1)
        cfi_adjust_cfa_offset(FRAMESIZE)
@@ -395,13 +398,16 @@ L(zero_padding_memset):
        mr      r3,r30       /* Restore the return value of strncpy, i.e.:
                                dest.  For stpncpy, the return value is the
                                same as return value of memset.  */
-       ld      r30,FRAMESIZE-8(r1) /* Restore r30.  */
+       ld      r30,FRAMESIZE-16(r1) /* Restore r30.  */
        /* Restore the stack frame.  */
        addi    r1,r1,FRAMESIZE
        cfi_adjust_cfa_offset(-FRAMESIZE)
        /* Restore the link register.  */
        mtlr    r0
        cfi_restore(lr)
+#ifdef __ROP_PROTECT__
+       hashchk 0,FRAME_ROP_SAVE(r1)
+#endif
        blr
 
 END (FUNC_NAME)

diff --git a/sysdeps/powerpc/powerpc64/power8/strncpy.S b/sysdeps/powerpc/powerpc64/power8/strncpy.S
index e68453bcaabadbc536d38cb1b3d3f8982288efa9..110c5304511cabaf81bd35106591431a178f4df5 100644 (file)
--- a/sysdeps/powerpc/powerpc64/power8/strncpy.S
+++ b/sysdeps/powerpc/powerpc64/power8/strncpy.S
@@ -81,26 +81,26 @@ ENTRY (FUNC_NAME, 4)
        rlwinm  r9,r4,0,19,19
 
        /* Save some non-volatile registers on the stack.  */
-       std     r26,-48(r1)
-       std     r27,-40(r1)
+       std     r26,-56(r1)
+       std     r27,-48(r1)
 
        rlwinm  r8,r10,0,19,19
 
-       std     r28,-32(r1)
-       std     r29,-24(r1)
+       std     r28,-40(r1)
+       std     r29,-32(r1)
 
        cmpld   cr7,r9,r8
 
-       std     r30,-16(r1)
-       std     r31,-8(r1)
+       std     r30,-24(r1)
+       std     r31,-16(r1)
 
        /* Update CFI.  */
-       cfi_offset(r26, -48)
-       cfi_offset(r27, -40)
-       cfi_offset(r28, -32)
-       cfi_offset(r29, -24)
-       cfi_offset(r30, -16)
-       cfi_offset(r31, -8)
+       cfi_offset(r26, -56)
+       cfi_offset(r27, -48)
+       cfi_offset(r28, -40)
+       cfi_offset(r29, -32)
+       cfi_offset(r30, -24)
+       cfi_offset(r31, -16)
 
        beq     cr7,L(unaligned_lt_16)
        rldicl  r9,r4,0,61
@@ -205,12 +205,12 @@ L(short_path_loop_end_1):
 #endif
 L(short_path_loop_end):
        /* Restore non-volatile registers.  */
-       ld      r26,-48(r1)
-       ld      r27,-40(r1)
-       ld      r28,-32(r1)
-       ld      r29,-24(r1)
-       ld      r30,-16(r1)
-       ld      r31,-8(r1)
+       ld      r26,-56(r1)
+       ld      r27,-48(r1)
+       ld      r28,-40(r1)
+       ld      r29,-32(r1)
+       ld      r30,-24(r1)
+       ld      r31,-16(r1)
        blr
 
        /* This code pads the remainder of dest with NULL bytes.  The algorithm
@@ -242,6 +242,9 @@ L(zero_pad_start_1):
        mflr    r0
        std     r0,16(r1)
 
+#ifdef __ROP_PROTECT__
+       hashst  0,FRAME_ROP_SAVE(r1)
+#endif
        /* Create the stack frame.  */
        stdu    r1,-FRAMESIZE(r1)
        cfi_adjust_cfa_offset(FRAMESIZE)
@@ -261,18 +264,21 @@ L(zero_pad_start_1):
 #endif
 
        /* Restore non-volatile registers and return.  */
-       ld      r26,FRAMESIZE-48(r1)
-       ld      r27,FRAMESIZE-40(r1)
-       ld      r28,FRAMESIZE-32(r1)
-       ld      r29,FRAMESIZE-24(r1)
-       ld      r30,FRAMESIZE-16(r1)
-       ld      r31,FRAMESIZE-8(r1)
+       ld      r26,FRAMESIZE-56(r1)
+       ld      r27,FRAMESIZE-48(r1)
+       ld      r28,FRAMESIZE-40(r1)
+       ld      r29,FRAMESIZE-32(r1)
+       ld      r30,FRAMESIZE-24(r1)
+       ld      r31,FRAMESIZE-16(r1)
        /* Restore the stack frame.  */
        addi    r1,r1,FRAMESIZE
        cfi_adjust_cfa_offset(-FRAMESIZE)
        /* Restore the link register.  */
        mtlr    r0
        cfi_restore(lr)
+#ifdef __ROP_PROTECT__
+       hashchk 0,FRAME_ROP_SAVE(r1)
+#endif
        blr
 
        /* The common case where [src]+16 will not cross a 4K page boundary.

diff --git a/sysdeps/powerpc/powerpc64/ppc-mcount.S b/sysdeps/powerpc/powerpc64/ppc-mcount.S
index 7296d6a87d09f071b7dda25cb56b63020b042401..91e422d6dae4439598547b6beb9a90b1811dd232 100644 (file)
--- a/sysdeps/powerpc/powerpc64/ppc-mcount.S
+++ b/sysdeps/powerpc/powerpc64/ppc-mcount.S
@@ -25,6 +25,9 @@ ENTRY(_mcount)
        mflr             r4
        ld               r11, 0(r1)
        std              r4, FRAME_LR_SAVE(r1)
+#ifdef __ROP_PROTECT__
+       hashst           r4, FRAME_ROP_SAVE(r1)
+#endif
        stdu             r1,-FRAME_MIN_SIZE(r1)
        cfi_adjust_cfa_offset (FRAME_MIN_SIZE)
        cfi_offset (lr, FRAME_LR_SAVE)
@@ -36,5 +39,8 @@ ENTRY(_mcount)
        ld               r0, FRAME_MIN_SIZE+FRAME_LR_SAVE(r1)
        mtlr             r0
        addi             r1,r1,FRAME_MIN_SIZE
+#ifdef __ROP_PROTECT__
+       hashchk          0, FRAME_ROP_SAVE(r1)
+#endif
        blr
 END(_mcount)

diff --git a/sysdeps/powerpc/powerpc64/sysdep.h b/sysdeps/powerpc/powerpc64/sysdep.h
index b5c70e526e52c8aaf943861a47966381b754f7af..a15d858f47ad469de952ac6d67bac220d961d3f1 100644 (file)
--- a/sysdeps/powerpc/powerpc64/sysdep.h
+++ b/sysdeps/powerpc/powerpc64/sysdep.h
@@ -32,7 +32,7 @@
 #define FRAME_PARM_SAVE                48
 #else
 #define FRAME_ROP_SAVE         -8
-#define FRAME_MIN_SIZE         32
+#define FRAME_MIN_SIZE         48  /* Includes space for the ROP save slot */
 #define FRAME_MIN_SIZE_PARM    112 /* Includes space for the ROP save slot */
 #define FRAME_TOC_SAVE         24
 #define FRAME_PARM_SAVE                32