[binutils-gdb] PR26466 UBSAN: elf32-mep.c:300 left shift of negative value
Alan Modra
amodra@sourceware.org
Mon Aug 31 10:59:31 GMT 2020
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=1a211fc7d87dc92c2c91d24d0424d8f0485587f9
commit 1a211fc7d87dc92c2c91d24d0424d8f0485587f9
Author: Alan Modra <amodra@gmail.com>
Date: Mon Aug 31 11:14:31 2020 +0930
PR26466 UBSAN: elf32-mep.c:300 left shift of negative value
PR 26466
* mep-relocs.pl (emit_apply): Handle HI16S adjustment. Use "u"
variable and rewrite signed overflow check.
* elf32-mep.c: Regenerate.
(mep_final_link_relocate): Delete "s".
Diff:
---
bfd/ChangeLog | 8 ++++++
bfd/elf32-mep.c | 80 ++++++++++++++++++++++++++-----------------------------
bfd/mep-relocs.pl | 19 +++++++------
3 files changed, 57 insertions(+), 50 deletions(-)
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 85fd9f42d1a..f972a5adb4f 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,11 @@
+2020-08-31 Alan Modra <amodra@gmail.com>
+
+ PR 26466
+ * mep-relocs.pl (emit_apply): Handle HI16S adjustment. Use "u"
+ variable and rewrite signed overflow check.
+ * elf32-mep.c: Regenerate.
+ (mep_final_link_relocate): Delete "s".
+
2020-08-31 Alan Modra <amodra@gmail.com>
PR 26461
diff --git a/bfd/elf32-mep.c b/bfd/elf32-mep.c
index c5775de6496..ef8c10049e3 100644
--- a/bfd/elf32-mep.c
+++ b/bfd/elf32-mep.c
@@ -43,26 +43,26 @@ static reloc_howto_type mep_elf_howto_table [] =
MEPREL (R_RELC, 0, 0, 0, 0, 0, N, 0),
/* MEPRELOC:HOWTO */
/* This section generated from bfd/mep-relocs.pl from include/elf/mep.h. */
- MEPREL (R_MEP_8, 0, 8, 0, 0, 0, U, 0xff),
- MEPREL (R_MEP_16, 1, 16, 0, 0, 0, U, 0xffff),
- MEPREL (R_MEP_32, 2, 32, 0, 0, 0, U, 0xffffffff),
+ MEPREL (R_MEP_8, 0, 8, 0, 0, 0, U, 0xff),
+ MEPREL (R_MEP_16, 1, 16, 0, 0, 0, U, 0xffff),
+ MEPREL (R_MEP_32, 2, 32, 0, 0, 0, U, 0xffffffff),
MEPREL (R_MEP_PCREL8A2, 1, 8, 1, 1, 1, S, 0x00fe),
MEPREL (R_MEP_PCREL12A2,1, 12, 1, 1, 1, S, 0x0ffe),
MEPREL (R_MEP_PCREL17A2,2, 17, 0, 1, 1, S, 0x0000ffff),
MEPREL (R_MEP_PCREL24A2,2, 24, 0, 1, 1, S, 0x07f0ffff),
MEPREL (R_MEP_PCABS24A2,2, 24, 0, 1, 0, U, 0x07f0ffff),
- MEPREL (R_MEP_LOW16, 2, 16, 0, 0, 0, N, 0x0000ffff),
- MEPREL (R_MEP_HI16U, 2, 32, 0,16, 0, N, 0x0000ffff),
- MEPREL (R_MEP_HI16S, 2, 32, 0,16, 0, N, 0x0000ffff),
- MEPREL (R_MEP_GPREL, 2, 16, 0, 0, 0, S, 0x0000ffff),
- MEPREL (R_MEP_TPREL, 2, 16, 0, 0, 0, S, 0x0000ffff),
- MEPREL (R_MEP_TPREL7, 1, 7, 0, 0, 0, U, 0x007f),
+ MEPREL (R_MEP_LOW16, 2, 16, 0, 0, 0, N, 0x0000ffff),
+ MEPREL (R_MEP_HI16U, 2, 32, 0,16, 0, N, 0x0000ffff),
+ MEPREL (R_MEP_HI16S, 2, 32, 0,16, 0, N, 0x0000ffff),
+ MEPREL (R_MEP_GPREL, 2, 16, 0, 0, 0, S, 0x0000ffff),
+ MEPREL (R_MEP_TPREL, 2, 16, 0, 0, 0, S, 0x0000ffff),
+ MEPREL (R_MEP_TPREL7, 1, 7, 0, 0, 0, U, 0x007f),
MEPREL (R_MEP_TPREL7A2, 1, 7, 1, 1, 0, U, 0x007e),
MEPREL (R_MEP_TPREL7A4, 1, 7, 2, 2, 0, U, 0x007c),
- MEPREL (R_MEP_UIMM24, 2, 24, 0, 0, 0, U, 0x00ffffff),
+ MEPREL (R_MEP_UIMM24, 2, 24, 0, 0, 0, U, 0x00ffffff),
MEPREL (R_MEP_ADDR24A4, 2, 24, 0, 2, 0, U, 0x00fcffff),
MEPREL (R_MEP_GNU_VTINHERIT,1, 0,16,32, 0, N, 0x0000),
- MEPREL (R_MEP_GNU_VTENTRY,1, 0,16,32, 0, N, 0x0000),
+ MEPREL (R_MEP_GNU_VTENTRY,1, 0,16,32, 0, N, 0x0000),
/* MEPRELOC:END */
};
@@ -221,7 +221,6 @@ mep_final_link_relocate
bfd_vma relocation)
{
unsigned long u;
- long s;
unsigned char *byte;
bfd_vma pc;
bfd_reloc_status_type r = bfd_reloc_ok;
@@ -242,12 +241,12 @@ mep_final_link_relocate
+ input_section->output_offset
+ rel->r_offset);
- s = relocation + rel->r_addend;
+ u = relocation + rel->r_addend;
byte = (unsigned char *)contents + rel->r_offset;
if (howto->type == R_MEP_PCREL24A2
- && s == 0
+ && u == 0
&& pc >= 0x800000)
{
/* This is an unreachable branch to an undefined weak function.
@@ -257,9 +256,7 @@ mep_final_link_relocate
}
if (howto->pc_relative)
- s -= pc;
-
- u = (unsigned long) s;
+ u -= pc;
switch (howto->type)
{
@@ -281,25 +278,25 @@ mep_final_link_relocate
byte[3^e4] = (u & 0xff);
break;
case R_MEP_PCREL8A2: /* --------7654321- */
- if (-128 > s || s > 127) r = bfd_reloc_overflow;
- byte[1^e2] = (byte[1^e2] & 0x01) | (s & 0xfe);
+ if (u + 128 > 255) r = bfd_reloc_overflow;
+ byte[1^e2] = (byte[1^e2] & 0x01) | (u & 0xfe);
break;
case R_MEP_PCREL12A2: /* ----ba987654321- */
- if (-2048 > s || s > 2047) r = bfd_reloc_overflow;
- byte[0^e2] = (byte[0^e2] & 0xf0) | ((s >> 8) & 0x0f);
- byte[1^e2] = (byte[1^e2] & 0x01) | (s & 0xfe);
+ if (u + 2048 > 4095) r = bfd_reloc_overflow;
+ byte[0^e2] = (byte[0^e2] & 0xf0) | ((u >> 8) & 0x0f);
+ byte[1^e2] = (byte[1^e2] & 0x01) | (u & 0xfe);
break;
case R_MEP_PCREL17A2: /* ----------------gfedcba987654321 */
- if (-65536 > s || s > 65535) r = bfd_reloc_overflow;
- byte[2^e2] = ((s >> 9) & 0xff);
- byte[3^e2] = ((s >> 1) & 0xff);
+ if (u + 65536 > 131071) r = bfd_reloc_overflow;
+ byte[2^e2] = ((u >> 9) & 0xff);
+ byte[3^e2] = ((u >> 1) & 0xff);
break;
case R_MEP_PCREL24A2: /* -----7654321----nmlkjihgfedcba98 */
- if (-8388608 > s || s > 8388607) r = bfd_reloc_overflow;
- byte[0^e2] = (byte[0^e2] & 0xf8) | ((s >> 5) & 0x07);
- byte[1^e2] = (byte[1^e2] & 0x0f) | ((s << 3) & 0xf0);
- byte[2^e2] = ((s >> 16) & 0xff);
- byte[3^e2] = ((s >> 8) & 0xff);
+ if (u + 8388608 > 16777215) r = bfd_reloc_overflow;
+ byte[0^e2] = (byte[0^e2] & 0xf8) | ((u >> 5) & 0x07);
+ byte[1^e2] = (byte[1^e2] & 0x0f) | ((u << 3) & 0xf0);
+ byte[2^e2] = ((u >> 16) & 0xff);
+ byte[3^e2] = ((u >> 8) & 0xff);
break;
case R_MEP_PCABS24A2: /* -----7654321----nmlkjihgfedcba98 */
if (u > 16777215) r = bfd_reloc_overflow;
@@ -317,22 +314,21 @@ mep_final_link_relocate
byte[3^e2] = ((u >> 16) & 0xff);
break;
case R_MEP_HI16S: /* ----------------vutsrqponmlkjihg */
- if (s & 0x8000)
- s += 0x10000;
- byte[2^e2] = ((s >> 24) & 0xff);
- byte[3^e2] = ((s >> 16) & 0xff);
+ u += 0x8000;
+ byte[2^e2] = ((u >> 24) & 0xff);
+ byte[3^e2] = ((u >> 16) & 0xff);
break;
case R_MEP_GPREL: /* ----------------fedcba9876543210 */
- s -= mep_sdaoff_base(rel->r_offset);
- if (-32768 > s || s > 32767) r = bfd_reloc_overflow;
- byte[2^e2] = ((s >> 8) & 0xff);
- byte[3^e2] = (s & 0xff);
+ u -= mep_sdaoff_base(rel->r_offset);
+ if (u + 32768 > 65535) r = bfd_reloc_overflow;
+ byte[2^e2] = ((u >> 8) & 0xff);
+ byte[3^e2] = (u & 0xff);
break;
case R_MEP_TPREL: /* ----------------fedcba9876543210 */
- s -= mep_tpoff_base(rel->r_offset);
- if (-32768 > s || s > 32767) r = bfd_reloc_overflow;
- byte[2^e2] = ((s >> 8) & 0xff);
- byte[3^e2] = (s & 0xff);
+ u -= mep_tpoff_base(rel->r_offset);
+ if (u + 32768 > 65535) r = bfd_reloc_overflow;
+ byte[2^e2] = ((u >> 8) & 0xff);
+ byte[3^e2] = (u & 0xff);
break;
case R_MEP_TPREL7: /* ---------6543210 */
u -= mep_tpoff_base(rel->r_offset);
diff --git a/bfd/mep-relocs.pl b/bfd/mep-relocs.pl
index 599ff6436a0..544ee012a77 100755
--- a/bfd/mep-relocs.pl
+++ b/bfd/mep-relocs.pl
@@ -156,20 +156,23 @@ sub emit_apply {
$e = '^e4' # endian swap for data
}
print NEW " case R_MEP_$relocs[$i]: /* $pattern[$i] */\n";
+ if ($relocs[$i] =~ /HI16S/) {
+ print NEW " u += 0x8000;\n"
+ }
if ($attrs[$i] =~ /tp-rel/i) {
- print NEW " $v -= mep_tpoff_base(rel->r_offset);\n";
+ print NEW " u -= mep_tpoff_base(rel->r_offset);\n";
}
if ($attrs[$i] =~ /gp-rel/i) {
- print NEW " $v -= mep_sdaoff_base(rel->r_offset);\n";
+ print NEW " u -= mep_sdaoff_base(rel->r_offset);\n";
}
if ($attrs[$i] !~ /no-overflow/ && $bits[$i] < 32) {
if ($v eq "u") {
$max = (1 << $bits[$i]) - 1;
print NEW " if (u > $max) r = bfd_reloc_overflow;\n";
} else {
- $min = -(1 << ($bits[$i]-1));
- $max = (1 << ($bits[$i]-1)) - 1;
- print NEW " if ($min > s || s > $max) r = bfd_reloc_overflow;\n";
+ $min = (1 << ($bits[$i]-1));
+ $max = (1 << ($bits[$i])) - 1;
+ print NEW " if (u + $min > $max) r = bfd_reloc_overflow;\n";
}
}
for ($b=0; $b<length($pattern[$i]); $b += 8) {
@@ -183,11 +186,11 @@ sub emit_apply {
print NEW " byte[$bb$e] = ";
print NEW "(byte[$bb$e] & 0x$rmask) | " if $rmask ne "00";
if ($left) {
- print NEW "(($v << $left) & 0x$mask)";
+ print NEW "((u << $left) & 0x$mask)";
} elsif ($right) {
- print NEW "(($v >> $right) & 0x$mask)";
+ print NEW "((u >> $right) & 0x$mask)";
} else {
- print NEW "($v & 0x$mask)";
+ print NEW "(u & 0x$mask)";
}
print NEW ";\n";
}
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