From: Dave Brolley <brolley@redhat.com>
To: Dave Brolley <brolley@redhat.com>
Cc: sid@sources.redhat.com
Subject: Re: Misaligned read/write of memory by GDB
Date: Mon, 28 Jun 2004 22:50:00 -0000 [thread overview]
Message-ID: <40E0A0B0.3020001@redhat.com> (raw)
In-Reply-To: <40E08B13.7000404@redhat.com>
[-- Attachment #1: Type: text/plain, Size: 650 bytes --]
Ooops, sent the wrong patch......
Dave Brolley wrote:
> Hi,
>
> Some sid components don't support misaligned reads/writes. The current
> cache components are the example which caused my particular problem.
> They punt on misaligned reads/writes, presumably so that they don't
> have to worry about accesses which cross cache line boundaries. This
> causes a problem when GDB attempts to read memory at unaligned addresses.
>
> This patch to gdb::process_get_mem and gdb::process_set_mem forces any
> unaligned requests to use the existing byte-at-a-time method.
>
> I've committed this patch. Let me know if there are any problems.
>
> Dave
>
[-- Attachment #2: sid-gdb-align.patch.txt --]
[-- Type: text/plain, Size: 4924 bytes --]
Index: sid/component/gdb/gdb.cxx
===================================================================
RCS file: /cvs/src/src/sid/component/gdb/gdb.cxx,v
retrieving revision 1.11
diff -c -p -r1.11 gdb.cxx
*** sid/component/gdb/gdb.cxx 22 Mar 2004 21:27:23 -0000 1.11
--- sid/component/gdb/gdb.cxx 28 Jun 2004 21:10:43 -0000
*************** gdb::process_get_mem (struct gdbserv_reg
*** 620,642 ****
}
host_int_4 addr = addr8; // truncate
! if (len==1 && e==endian_big)
! read_bus_word (gdbserv, memory, addr, big_int_1());
! else if (len==1 && e==endian_little)
! read_bus_word (gdbserv, memory, addr, little_int_1());
! else if (len==2 && e==endian_big)
! read_bus_word (gdbserv, memory, addr, big_int_2());
! else if (len==2 && e==endian_little)
! read_bus_word (gdbserv, memory, addr, little_int_2());
! else if (len==4 && e==endian_big)
! read_bus_word (gdbserv, memory, addr, big_int_4());
! else if (len==4 && e==endian_little)
! read_bus_word (gdbserv, memory, addr, little_int_4());
! else if (len==8 && e==endian_big)
! read_bus_word (gdbserv, memory, addr, big_int_8());
! else if (len==8 && e==endian_little)
! read_bus_word (gdbserv, memory, addr, little_int_8());
! else if (e==endian_little)
{
for (unsigned long i=0; i<len; i++)
read_bus_word (gdbserv, memory, addr + i, little_int_1());
--- 620,647 ----
}
host_int_4 addr = addr8; // truncate
! if (addr % len == 0)
! {
! if (len==1 && e==endian_big)
! { read_bus_word (gdbserv, memory, addr, big_int_1()); return; }
! if (len==1 && e==endian_little)
! { read_bus_word (gdbserv, memory, addr, little_int_1()); return; }
! if (len==2 && e==endian_big)
! { read_bus_word (gdbserv, memory, addr, big_int_2()); return; }
! if (len==2 && e==endian_little)
! { read_bus_word (gdbserv, memory, addr, little_int_2()); return; }
! if (len==4 && e==endian_big)
! { read_bus_word (gdbserv, memory, addr, big_int_4()); return; }
! if (len==4 && e==endian_little)
! { read_bus_word (gdbserv, memory, addr, little_int_4()); return; }
! if (len==8 && e==endian_big)
! { read_bus_word (gdbserv, memory, addr, big_int_8()); return; }
! if (len==8 && e==endian_little)
! { read_bus_word (gdbserv, memory, addr, little_int_8()); return; }
! }
!
! // Unaligned access or unsupported size.
! if (e==endian_little)
{
for (unsigned long i=0; i<len; i++)
read_bus_word (gdbserv, memory, addr + i, little_int_1());
*************** gdb::process_set_mem (struct gdbserv_reg
*** 700,722 ****
}
host_int_4 addr = addr8; // truncate
! if (len==1 && e==endian_big)
! write_bus_word (gdbserv, binary, memory, addr, big_int_1());
! else if (len==1 && e==endian_little)
! write_bus_word (gdbserv, binary, memory, addr, little_int_1());
! else if (len==2 && e==endian_big)
! write_bus_word (gdbserv, binary, memory, addr, big_int_2());
! else if (len==2 && e==endian_little)
! write_bus_word (gdbserv, binary, memory, addr, little_int_2());
! else if (len==4 && e==endian_big)
! write_bus_word (gdbserv, binary, memory, addr, big_int_4());
! else if (len==4 && e==endian_little)
! write_bus_word (gdbserv, binary, memory, addr, little_int_4());
! else if (len==8 && e==endian_big)
! write_bus_word (gdbserv, binary, memory, addr, big_int_8());
! else if (len==8 && e==endian_little)
! write_bus_word (gdbserv, binary, memory, addr, little_int_8());
! else if (e==endian_little)
{
for (unsigned long i=0; i<len; i++)
write_bus_word (gdbserv, binary, memory, addr + i, little_int_1());
--- 705,732 ----
}
host_int_4 addr = addr8; // truncate
! if (addr % len == 0)
! {
! if (len==1 && e==endian_big)
! { write_bus_word (gdbserv, binary, memory, addr, big_int_1()); return; }
! if (len==1 && e==endian_little)
! { write_bus_word (gdbserv, binary, memory, addr, little_int_1()); return; }
! if (len==2 && e==endian_big)
! { write_bus_word (gdbserv, binary, memory, addr, big_int_2()); return; }
! if (len==2 && e==endian_little)
! { write_bus_word (gdbserv, binary, memory, addr, little_int_2()); return; }
! if (len==4 && e==endian_big)
! { write_bus_word (gdbserv, binary, memory, addr, big_int_4()); return; }
! if (len==4 && e==endian_little)
! { write_bus_word (gdbserv, binary, memory, addr, little_int_4()); return; }
! if (len==8 && e==endian_big)
! { write_bus_word (gdbserv, binary, memory, addr, big_int_8()); return; }
! if (len==8 && e==endian_little)
! { write_bus_word (gdbserv, binary, memory, addr, little_int_8()); return; }
! }
!
! // Unaligned access or unsupported size.
! if (e==endian_little)
{
for (unsigned long i=0; i<len; i++)
write_bus_word (gdbserv, binary, memory, addr + i, little_int_1());
next prev parent reply other threads:[~2004-06-28 22:50 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-06-28 21:18 Dave Brolley
2004-06-28 22:50 ` Dave Brolley [this message]
2004-06-29 18:27 ` Frank Ch. Eigler
2004-06-29 19:14 ` Dave Brolley
2004-06-29 19:18 ` Frank Ch. Eigler
2004-06-29 20:40 ` Dave Brolley
2004-07-01 17:02 ` Dave Brolley
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