* PATCH: Fix read_leb128 in readelf for 64bit host
@ 2004-12-26 0:42 H. J. Lu
2004-12-27 19:01 ` H. J. Lu
0 siblings, 1 reply; 5+ messages in thread
From: H. J. Lu @ 2004-12-26 0:42 UTC (permalink / raw)
To: binutils
read_leb128 in readelf assumes long == int == 32bit. It doesn't work
with 64bit host. Does this patch look right?
H.J.
---
2004-12-25 H.J. Lu <hongjiu.lu@intel.com>
* readelf.c (read_leb128): Support 64bit host.
--- binutils/readelf.c.leb 2004-12-10 14:20:22.000000000 -0800
+++ binutils/readelf.c 2004-12-25 16:16:54.615198445 -0800
@@ -6933,7 +6933,7 @@ read_leb128 (unsigned char *data, int *l
{
unsigned long int result = 0;
unsigned int num_read = 0;
- int shift = 0;
+ unsigned int shift = 0;
unsigned char byte;
do
@@ -6951,8 +6951,8 @@ read_leb128 (unsigned char *data, int *l
if (length_return != NULL)
*length_return = num_read;
- if (sign && (shift < 32) && (byte & 0x40))
- result |= -1 << shift;
+ if (sign && (shift < 8 * sizeof (result)) && (byte & 0x40))
+ result |= -1L << shift;
return result;
}
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: PATCH: Fix read_leb128 in readelf for 64bit host
2004-12-26 0:42 PATCH: Fix read_leb128 in readelf for 64bit host H. J. Lu
@ 2004-12-27 19:01 ` H. J. Lu
2004-12-28 13:15 ` Dave Korn
0 siblings, 1 reply; 5+ messages in thread
From: H. J. Lu @ 2004-12-27 19:01 UTC (permalink / raw)
To: binutils; +Cc: GDB
[-- Attachment #1: Type: text/plain, Size: 1261 bytes --]
On Sat, Dec 25, 2004 at 04:42:29PM -0800, H. J. Lu wrote:
> read_leb128 in readelf assumes long == int == 32bit. It doesn't work
> with 64bit host. Does this patch look right?
>
>
I am going to check in this patch. Gdb 6.3 has the same problem. I
am enclosing a patch here.
H.J.
----
2004-12-27 H.J. Lu <hongjiu.lu@intel.com>
* readelf.c (read_leb128): Support 64bit host.
--- binutils/readelf.c.leb 2004-12-10 14:20:22.000000000 -0800
+++ binutils/readelf.c 2004-12-27 10:49:33.689234088 -0800
@@ -6933,7 +6933,7 @@ read_leb128 (unsigned char *data, int *l
{
unsigned long int result = 0;
unsigned int num_read = 0;
- int shift = 0;
+ unsigned int shift = 0;
unsigned char byte;
do
@@ -6941,7 +6941,7 @@ read_leb128 (unsigned char *data, int *l
byte = *data++;
num_read++;
- result |= (byte & 0x7f) << shift;
+ result |= ((unsigned long int) (byte & 0x7f)) << shift;
shift += 7;
@@ -6951,8 +6951,8 @@ read_leb128 (unsigned char *data, int *l
if (length_return != NULL)
*length_return = num_read;
- if (sign && (shift < 32) && (byte & 0x40))
- result |= -1 << shift;
+ if (sign && (shift < 8 * sizeof (result)) && (byte & 0x40))
+ result |= -1L << shift;
return result;
}
[-- Attachment #2: gdb-leb128-1.patch --]
[-- Type: text/plain, Size: 639 bytes --]
2004-12-27 H.J. Lu <hongjiu.lu@intel.com>
* dwarf2read.c (read_signed_leb128): Support 64bit host.
--- gdb/dwarf2read.c.leb 2004-12-21 14:24:06.000000000 -0800
+++ gdb/dwarf2read.c 2004-12-27 10:55:02.912450066 -0800
@@ -6098,7 +6098,7 @@ read_signed_leb128 (bfd *abfd, char *buf
result = 0;
shift = 0;
- size = 32;
+ size = 8 * sizeof (result);
num_read = 0;
i = 0;
while (1)
@@ -6115,7 +6115,7 @@ read_signed_leb128 (bfd *abfd, char *buf
}
if ((shift < size) && (byte & 0x40))
{
- result |= -(1 << shift);
+ result |= -(1L << shift);
}
*bytes_read_ptr = num_read;
return result;
^ permalink raw reply [flat|nested] 5+ messages in thread* RE: PATCH: Fix read_leb128 in readelf for 64bit host
2004-12-27 19:01 ` H. J. Lu
@ 2004-12-28 13:15 ` Dave Korn
2004-12-28 14:57 ` Daniel Jacobowitz
0 siblings, 1 reply; 5+ messages in thread
From: Dave Korn @ 2004-12-28 13:15 UTC (permalink / raw)
To: 'H. J. Lu', binutils; +Cc: 'GDB'
> -----Original Message-----
> From: binutils-owner On Behalf Of H. J. Lu
> Sent: 27 December 2004 19:02
> On Sat, Dec 25, 2004 at 04:42:29PM -0800, H. J. Lu wrote:
> > read_leb128 in readelf assumes long == int == 32bit. It doesn't work
> > with 64bit host. Does this patch look right?
> >
> >
>
> I am going to check in this patch. Gdb 6.3 has the same problem. I
> am enclosing a patch here.
> --- binutils/readelf.c.leb 2004-12-10 14:20:22.000000000 -0800
> +++ binutils/readelf.c 2004-12-27 10:49:33.689234088 -0800
> @@ -6933,7 +6933,7 @@ read_leb128 (unsigned char *data, int *l
> {
> unsigned long int result = 0;
> unsigned int num_read = 0;
> - int shift = 0;
> + unsigned int shift = 0;
> unsigned char byte;
>
> do
> @@ -6941,7 +6941,7 @@ read_leb128 (unsigned char *data, int *l
> byte = *data++;
> num_read++;
>
> - result |= (byte & 0x7f) << shift;
> + result |= ((unsigned long int) (byte & 0x7f)) << shift;
>
> shift += 7;
>
> @@ -6951,8 +6951,8 @@ read_leb128 (unsigned char *data, int *l
> if (length_return != NULL)
> *length_return = num_read;
>
> - if (sign && (shift < 32) && (byte & 0x40))
> - result |= -1 << shift;
> + if (sign && (shift < 8 * sizeof (result)) && (byte & 0x40))
> + result |= -1L << shift;
>
> return result;
> }
>
IIRC the C spec says shift amounts >=32 are undefined behaviour, even in the
presence of larger integer types. Is shift ever going to be >= 32 for 64 bit
hosts in these functions? (I suspect it will). If so, the shift must be
decomposed into two smaller shifts, no?
cheers,
DaveK
--
Can't think of a witty .sigline today....
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: PATCH: Fix read_leb128 in readelf for 64bit host
2004-12-28 13:15 ` Dave Korn
@ 2004-12-28 14:57 ` Daniel Jacobowitz
2004-12-28 20:48 ` Dave Korn
0 siblings, 1 reply; 5+ messages in thread
From: Daniel Jacobowitz @ 2004-12-28 14:57 UTC (permalink / raw)
To: Dave Korn; +Cc: 'H. J. Lu', binutils, 'GDB'
On Tue, Dec 28, 2004 at 01:13:14PM -0000, Dave Korn wrote:
> IIRC
You don't :-) C99 6.5.7#3...
> the C spec says shift amounts >=32 are undefined behaviour, even in the
> presence of larger integer types.
--
Daniel Jacobowitz
^ permalink raw reply [flat|nested] 5+ messages in thread
* RE: PATCH: Fix read_leb128 in readelf for 64bit host
2004-12-28 14:57 ` Daniel Jacobowitz
@ 2004-12-28 20:48 ` Dave Korn
0 siblings, 0 replies; 5+ messages in thread
From: Dave Korn @ 2004-12-28 20:48 UTC (permalink / raw)
To: 'Daniel Jacobowitz'; +Cc: 'H. J. Lu', binutils, 'GDB'
> -----Original Message-----
> From: Daniel Jacobowitz
> Sent: 28 December 2004 14:57
> To: Dave Korn
> Cc: 'H. J. Lu'; binutils@sources.redhat.com; 'GDB'
> Subject: Re: PATCH: Fix read_leb128 in readelf for 64bit host
>
> On Tue, Dec 28, 2004 at 01:13:14PM -0000, Dave Korn wrote:
> > IIRC
>
> You don't :-) C99 6.5.7#3...
Jolly good then!
cheers,
DaveK
--
Can't think of a witty .sigline today....
^ permalink raw reply [flat|nested] 5+ messages in thread
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2004-12-26 0:42 PATCH: Fix read_leb128 in readelf for 64bit host H. J. Lu
2004-12-27 19:01 ` H. J. Lu
2004-12-28 13:15 ` Dave Korn
2004-12-28 14:57 ` Daniel Jacobowitz
2004-12-28 20:48 ` Dave Korn
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