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[BFD][AARCH64]Properly truncate no overflow checking relocation value for load/store immediate.
- From: Renlin Li <renlin dot li at foss dot arm dot com>
- To: "binutils at sourceware dot org" <binutils at sourceware dot org>
- Cc: Nicholas Clifton <nickc at redhat dot com>, Ramana Radhakrishnan <Ramana dot Radhakrishnan at arm dot com>, Peter Smith <peter dot smith at linaro dot org>
- Date: Thu, 26 Apr 2018 14:05:45 +0100
- Subject: [BFD][AARCH64]Properly truncate no overflow checking relocation value for load/store immediate.
Hi all,
In aarch64, there are relocations for the unsigned immediate offset of load/store instruction.
The size of the immediate field is 12-bit. In the scaled case, not all 12-bit will be used.
For example: R_AARCH64_LD64_GOT_LO12_NC
Set the LD/ST immediate field to bits [11:3] of relocated value. No overflow
check.
In this case, the top 3 bits of the immediate field of the load instruction should
be all 0. Only 9 bits from the value should be written into the instruction
encoding.
For relocations with over-flow check, if the value is larger than 12-bits, it
will be caught by the checking mechanism.
But for relocations without no overflow check, the value could be larger than
12 bits, after scaling, it might take more bits than the specification
specified. The value should be properly truncated.
The patch here correct the bitsize field of a few relocations, and the bitsize
field is used to properly truncate the value written into the instruction encoding.
Okay to commit?
bfd/ChangeLog:
2018-04-26 Renlin Li <renlin.li@arm.com>
* elfnn-aarch64.c (elfNN_aarch64_howto_table): Correct the bitsize
field of R_AARCH64_LD64_GOT_LO12_NC, R_AARCH64_P32_LD32_GOT_LO12_NC,
R_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC,
R_AARCH64_P32_LD32_GOTTPREL_LO12_NC,
R_AARCH64_LDST16_ABS_LO12_NC,
R_AARCH64_P32_TLSDESC_LD32_LO12_NC.
R_AARCH64_P32_TLSDESC_LD32_LO12_NC.
R_AARCH64_TLSDESC_LD64_LO12_NC.
R_AARCH64_LDST32_ABS_LO12_NC,
R_AARCH64_LDST64_ABS_LO12_NC,
R_AARCH64_LDST128_ABS_LO12_NC,
* elfxx-aarch64.c (_bfd_aarch64_elf_put_addend): Truncate the
immediate value for load/store instruction.
ld/ChangeLog:
2018-04-26 Renlin Li <renlin.li@arm.com>
* testsuite/ld-aarch64/emit-relocs-115.d: Update test with new value.
* testsuite/ld-aarch64/emit-relocs-534.d: Likewise.
* testsuite/ld-aarch64/emit-relocs-555.d: Likewise.
diff --git a/bfd/elfnn-aarch64.c b/bfd/elfnn-aarch64.c
index 3ccca779ff79cb83d3f2fc7de50bb258a55f94bb..d71aae59e1bb6ca0cc6c1e31d4f77d3e730b30a1 100644
--- a/bfd/elfnn-aarch64.c
+++ b/bfd/elfnn-aarch64.c
@@ -892,7 +892,7 @@ static reloc_howto_type elfNN_aarch64_howto_table[] =
HOWTO (AARCH64_R (LDST16_ABS_LO12_NC), /* type */
1, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
- 12, /* bitsize */
+ 11, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
@@ -907,7 +907,7 @@ static reloc_howto_type elfNN_aarch64_howto_table[] =
HOWTO (AARCH64_R (LDST32_ABS_LO12_NC), /* type */
2, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
- 12, /* bitsize */
+ 10, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
@@ -922,7 +922,7 @@ static reloc_howto_type elfNN_aarch64_howto_table[] =
HOWTO (AARCH64_R (LDST64_ABS_LO12_NC), /* type */
3, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
- 12, /* bitsize */
+ 9, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
@@ -937,7 +937,7 @@ static reloc_howto_type elfNN_aarch64_howto_table[] =
HOWTO (AARCH64_R (LDST128_ABS_LO12_NC), /* type */
4, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
- 12, /* bitsize */
+ 8, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
@@ -984,7 +984,7 @@ static reloc_howto_type elfNN_aarch64_howto_table[] =
HOWTO64 (AARCH64_R (LD64_GOT_LO12_NC), /* type */
3, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
- 12, /* bitsize */
+ 9, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
@@ -999,7 +999,7 @@ static reloc_howto_type elfNN_aarch64_howto_table[] =
HOWTO32 (AARCH64_R (LD32_GOT_LO12_NC), /* type */
2, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
- 12, /* bitsize */
+ 10, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
@@ -1179,7 +1179,7 @@ static reloc_howto_type elfNN_aarch64_howto_table[] =
HOWTO64 (AARCH64_R (TLSIE_LD64_GOTTPREL_LO12_NC), /* type */
3, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
- 12, /* bitsize */
+ 9, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
@@ -1193,7 +1193,7 @@ static reloc_howto_type elfNN_aarch64_howto_table[] =
HOWTO32 (AARCH64_R (TLSIE_LD32_GOTTPREL_LO12_NC), /* type */
2, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
- 12, /* bitsize */
+ 10, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
@@ -1811,7 +1811,7 @@ static reloc_howto_type elfNN_aarch64_howto_table[] =
HOWTO64 (AARCH64_R (TLSDESC_LD64_LO12), /* type */
3, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
- 12, /* bitsize */
+ 9, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
@@ -1826,7 +1826,7 @@ static reloc_howto_type elfNN_aarch64_howto_table[] =
HOWTO32 (AARCH64_R (TLSDESC_LD32_LO12_NC), /* type */
2, /* rightshift */
2, /* size (0 = byte, 1 = short, 2 = long) */
- 12, /* bitsize */
+ 10, /* bitsize */
FALSE, /* pc_relative */
0, /* bitpos */
complain_overflow_dont, /* complain_on_overflow */
diff --git a/bfd/elfxx-aarch64.c b/bfd/elfxx-aarch64.c
index 08e7cd9684cf4621ac6c2843d8bc82a3d21b4a6a..7da1fdaf70870bc9b9d744ba5fbf1a15ea892dd0 100644
--- a/bfd/elfxx-aarch64.c
+++ b/bfd/elfxx-aarch64.c
@@ -263,36 +263,40 @@ _bfd_aarch64_elf_put_addend (bfd *abfd,
contents = reencode_add_imm (contents, addend);
break;
- case BFD_RELOC_AARCH64_LD32_GOTPAGE_LO14:
case BFD_RELOC_AARCH64_LD32_GOT_LO12_NC:
- case BFD_RELOC_AARCH64_LD64_GOTOFF_LO15:
- case BFD_RELOC_AARCH64_LD64_GOTPAGE_LO15:
case BFD_RELOC_AARCH64_LD64_GOT_LO12_NC:
+ case BFD_RELOC_AARCH64_TLSDESC_LD32_LO12_NC:
+ case BFD_RELOC_AARCH64_TLSIE_LD32_GOTTPREL_LO12_NC:
+ case BFD_RELOC_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC:
+ case BFD_RELOC_AARCH64_TLSLD_LDST16_DTPREL_LO12_NC:
+ case BFD_RELOC_AARCH64_TLSLD_LDST32_DTPREL_LO12_NC:
+ case BFD_RELOC_AARCH64_TLSLD_LDST64_DTPREL_LO12_NC:
+ case BFD_RELOC_AARCH64_TLSLD_LDST8_DTPREL_LO12_NC:
+ case BFD_RELOC_AARCH64_TLSLE_LDST16_TPREL_LO12_NC:
+ case BFD_RELOC_AARCH64_TLSLE_LDST32_TPREL_LO12_NC:
+ case BFD_RELOC_AARCH64_TLSLE_LDST64_TPREL_LO12_NC:
+ case BFD_RELOC_AARCH64_TLSLE_LDST8_TPREL_LO12_NC:
+ /* Properly truncate the value according to the bitsize. */
+ addend &= ((1 << howto->bitsize) - 1);
+ /* Fall through. */
+
+ case BFD_RELOC_AARCH64_LD32_GOTPAGE_LO14:
+ case BFD_RELOC_AARCH64_LD64_GOTPAGE_LO15:
+ case BFD_RELOC_AARCH64_LD64_GOTOFF_LO15:
case BFD_RELOC_AARCH64_LDST128_LO12:
case BFD_RELOC_AARCH64_LDST16_LO12:
case BFD_RELOC_AARCH64_LDST32_LO12:
case BFD_RELOC_AARCH64_LDST64_LO12:
case BFD_RELOC_AARCH64_LDST8_LO12:
- case BFD_RELOC_AARCH64_TLSDESC_LD32_LO12_NC:
case BFD_RELOC_AARCH64_TLSDESC_LD64_LO12:
- case BFD_RELOC_AARCH64_TLSIE_LD32_GOTTPREL_LO12_NC:
- case BFD_RELOC_AARCH64_TLSIE_LD64_GOTTPREL_LO12_NC:
case BFD_RELOC_AARCH64_TLSLD_LDST16_DTPREL_LO12:
- case BFD_RELOC_AARCH64_TLSLD_LDST16_DTPREL_LO12_NC:
case BFD_RELOC_AARCH64_TLSLD_LDST32_DTPREL_LO12:
- case BFD_RELOC_AARCH64_TLSLD_LDST32_DTPREL_LO12_NC:
case BFD_RELOC_AARCH64_TLSLD_LDST64_DTPREL_LO12:
- case BFD_RELOC_AARCH64_TLSLD_LDST64_DTPREL_LO12_NC:
case BFD_RELOC_AARCH64_TLSLD_LDST8_DTPREL_LO12:
- case BFD_RELOC_AARCH64_TLSLD_LDST8_DTPREL_LO12_NC:
case BFD_RELOC_AARCH64_TLSLE_LDST16_TPREL_LO12:
- case BFD_RELOC_AARCH64_TLSLE_LDST16_TPREL_LO12_NC:
case BFD_RELOC_AARCH64_TLSLE_LDST32_TPREL_LO12:
- case BFD_RELOC_AARCH64_TLSLE_LDST32_TPREL_LO12_NC:
case BFD_RELOC_AARCH64_TLSLE_LDST64_TPREL_LO12:
- case BFD_RELOC_AARCH64_TLSLE_LDST64_TPREL_LO12_NC:
case BFD_RELOC_AARCH64_TLSLE_LDST8_TPREL_LO12:
- case BFD_RELOC_AARCH64_TLSLE_LDST8_TPREL_LO12_NC:
if (old_addend & ((1 << howto->rightshift) - 1))
return bfd_reloc_overflow;
/* Used for ldr*|str* rt, [rn, #uimm12] to provide the low order
diff --git a/ld/testsuite/ld-aarch64/emit-relocs-115.d b/ld/testsuite/ld-aarch64/emit-relocs-115.d
index f436d32c61fca5abf7b1b59fa822fbc086dc9722..95a6e317448513a8afa0739adf3533de6fe2f90f 100644
--- a/ld/testsuite/ld-aarch64/emit-relocs-115.d
+++ b/ld/testsuite/ld-aarch64/emit-relocs-115.d
@@ -6,5 +6,5 @@
00010000 <.text>:
10000: 798019d6 ldrsh x22, \[x14, #12\]
10000: R_AARCH64_P32_TLSLE_LDST16_TPREL_LO12_NC v2
- 10004: 79a72a28 ldrsh x8, \[x17, #5012\]
+ 10004: 79872a28 ldrsh x8, \[x17, #916\]
10004: R_AARCH64_P32_TLSLE_LDST16_TPREL_LO12_NC v3
diff --git a/ld/testsuite/ld-aarch64/emit-relocs-534.d b/ld/testsuite/ld-aarch64/emit-relocs-534.d
index 121fdc4c0b2330475fff04ebd32dc66ba293382d..fe59b23182d1adff2786a6e7559a38c1c1230940 100644
--- a/ld/testsuite/ld-aarch64/emit-relocs-534.d
+++ b/ld/testsuite/ld-aarch64/emit-relocs-534.d
@@ -5,5 +5,5 @@
0000000000010000 <.text>:
10000: 798009d6 ldrsh x22, \[x14, #4\]
10000: R_AARCH64_TLSLD_LDST16_DTPREL_LO12_NC v2
- 10004: 79a71a28 ldrsh x8, \[x17, #5004\]
+ 10004: 79871a28 ldrsh x8, \[x17, #908\]
10004: R_AARCH64_TLSLD_LDST16_DTPREL_LO12_NC v3
diff --git a/ld/testsuite/ld-aarch64/emit-relocs-555.d b/ld/testsuite/ld-aarch64/emit-relocs-555.d
index e866b6034c4405edaf4459f2b0aa22697458075a..1e33998e3579b674e707c659facc3e5b3f988f77 100644
--- a/ld/testsuite/ld-aarch64/emit-relocs-555.d
+++ b/ld/testsuite/ld-aarch64/emit-relocs-555.d
@@ -5,5 +5,5 @@
0000000000010000 <.text>:
10000: 798029d6 ldrsh x22, \[x14, #20\]
10000: R_AARCH64_TLSLE_LDST16_TPREL_LO12_NC v2
- 10004: 79a73a28 ldrsh x8, \[x17, #5020\]
+ 10004: 79873a28 ldrsh x8, \[x17, #924\]
10004: R_AARCH64_TLSLE_LDST16_TPREL_LO12_NC v3