Thread: [Kgdb-bugreport] wrong symbols with kgdb
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From: sfora d. <sfo...@gm...> - 2007-12-17 15:58:46
|
Hello all, I am trying to debug a remote kernel using kgdb. host is x86, target is i386 (2.6.23) (under vmware), connection completes fine. Problem is - some of the symbols are plain wrong. For example - "p load_elf_binary" yields 0x802a4990 while that function naturally resides above 0xc0000000. When I run gdb ./vmlinux inside the target itself, running the same "p" command give me the correct result.. any Idea why this happens and how can I fix it ? Can I supply gdb the updated System.map or something ? thanks sfora |
From: Derek A. <warlord@MIT.EDU> - 2007-12-17 16:12:36
|
Are you by chance running a Fedora kernel? If so the problem is the kernel physical start vs. physical align. -derek Quoting sfora dim <sfo...@gm...>: > Hello all, > > I am trying to debug a remote kernel using kgdb. > host is x86, target is i386 (2.6.23) (under vmware), connection > completes fine. > Problem is - some of the symbols are plain wrong. > > For example - "p load_elf_binary" yields 0x802a4990 while that > function naturally resides above 0xc0000000. > > When I run gdb ./vmlinux inside the target itself, running the same "p" > command give me the correct result.. > > any Idea why this happens and how can I fix it ? > > Can I supply gdb the updated System.map or something ? > > thanks > sfora > > ------------------------------------------------------------------------- > SF.Net email is sponsored by: > Check out the new SourceForge.net Marketplace. > It's the best place to buy or sell services > for just about anything Open Source. > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > _______________________________________________ > Kgdb-bugreport mailing list > Kgd...@li... > https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport > -- Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory Member, MIT Student Information Processing Board (SIPB) URL: http://web.mit.edu/warlord/ PP-ASEL-IA N1NWH warlord@MIT.EDU PGP key available |
From: sfora d. <sfo...@gm...> - 2007-12-17 16:17:46
|
On 12/17/07, Derek Atkins <wa...@mi...> wrote: > Are you by chance running a Fedora kernel? If so the problem is > the kernel physical start vs. physical align. Uhm, the target is FC8 but a kernel I have just compiled (v2.6.23 branch of jason's kgdb git tree). Host is Ubuntu 7.04. I am compiling on the host, and transfering the binary to the target using NFS. > > -derek > > Quoting sfora dim <sfo...@gm...>: > > > Hello all, > > > > I am trying to debug a remote kernel using kgdb. > > host is x86, target is i386 (2.6.23) (under vmware), connection > > completes fine. > > Problem is - some of the symbols are plain wrong. > > > > For example - "p load_elf_binary" yields 0x802a4990 while that > > function naturally resides above 0xc0000000. > > > > When I run gdb ./vmlinux inside the target itself, running the same "p" > > command give me the correct result.. > > > > any Idea why this happens and how can I fix it ? > > > > Can I supply gdb the updated System.map or something ? > > > > thanks > > sfora > > > > ------------------------------------------------------------------------- > > SF.Net email is sponsored by: > > Check out the new SourceForge.net Marketplace. > > It's the best place to buy or sell services > > for just about anything Open Source. > > http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > > _______________________________________________ > > Kgdb-bugreport mailing list > > Kgd...@li... > > https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport > > > > > > -- > Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory > Member, MIT Student Information Processing Board (SIPB) > URL: http://web.mit.edu/warlord/ PP-ASEL-IA N1NWH > warlord@MIT.EDU PGP key available > > |
From: Derek A. <warlord@MIT.EDU> - 2007-12-17 16:37:35
|
What .config did you use/start with? Did you check the physical start/align settings? Are they the same or are they different? -derek Quoting sfora dim <sfo...@gm...>: > On 12/17/07, Derek Atkins <wa...@mi...> wrote: >> Are you by chance running a Fedora kernel? If so the problem is >> the kernel physical start vs. physical align. > > Uhm, the target is FC8 but a kernel I have just compiled > (v2.6.23 branch of jason's kgdb git tree). > Host is Ubuntu 7.04. > > I am compiling on the host, and transfering the binary to the target > using NFS. > >> >> -derek >> >> Quoting sfora dim <sfo...@gm...>: >> >> > Hello all, >> > >> > I am trying to debug a remote kernel using kgdb. >> > host is x86, target is i386 (2.6.23) (under vmware), connection >> > completes fine. >> > Problem is - some of the symbols are plain wrong. >> > >> > For example - "p load_elf_binary" yields 0x802a4990 while that >> > function naturally resides above 0xc0000000. >> > >> > When I run gdb ./vmlinux inside the target itself, running the same "p" >> > command give me the correct result.. >> > >> > any Idea why this happens and how can I fix it ? >> > >> > Can I supply gdb the updated System.map or something ? >> > >> > thanks >> > sfora >> > >> > ------------------------------------------------------------------------- >> > SF.Net email is sponsored by: >> > Check out the new SourceForge.net Marketplace. >> > It's the best place to buy or sell services >> > for just about anything Open Source. >> > >> http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace >> > _______________________________________________ >> > Kgdb-bugreport mailing list >> > Kgd...@li... >> > https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport >> > >> >> >> >> -- >> Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory >> Member, MIT Student Information Processing Board (SIPB) >> URL: http://web.mit.edu/warlord/ PP-ASEL-IA N1NWH >> warlord@MIT.EDU PGP key available >> >> > -- Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory Member, MIT Student Information Processing Board (SIPB) URL: http://web.mit.edu/warlord/ PP-ASEL-IA N1NWH warlord@MIT.EDU PGP key available |
From: sfora d. <sfo...@gm...> - 2007-12-17 16:51:09
|
On 12/17/07, Derek Atkins <wa...@mi...> wrote: > What .config did you use/start with? Did you check the physical > start/align settings? Are they the same or are they different? Do you mean these settings: CONFIG_PHYSICAL_ALIGN=0x100000 CONFIG_PHYSICAL_START=0x100000 ? Looks like they are the same... > > -derek > > Quoting sfora dim <sfo...@gm...>: > > > On 12/17/07, Derek Atkins <wa...@mi...> wrote: > >> Are you by chance running a Fedora kernel? If so the problem is > >> the kernel physical start vs. physical align. > > > > Uhm, the target is FC8 but a kernel I have just compiled > > (v2.6.23 branch of jason's kgdb git tree). > > Host is Ubuntu 7.04. > > > > I am compiling on the host, and transfering the binary to the target > > using NFS. > > > >> > >> -derek > >> > >> Quoting sfora dim <sfo...@gm...>: > >> > >> > Hello all, > >> > > >> > I am trying to debug a remote kernel using kgdb. > >> > host is x86, target is i386 (2.6.23) (under vmware), connection > >> > completes fine. > >> > Problem is - some of the symbols are plain wrong. > >> > > >> > For example - "p load_elf_binary" yields 0x802a4990 while that > >> > function naturally resides above 0xc0000000. > >> > > >> > When I run gdb ./vmlinux inside the target itself, running the same "p" > >> > command give me the correct result.. > >> > > >> > any Idea why this happens and how can I fix it ? > >> > > >> > Can I supply gdb the updated System.map or something ? > >> > > >> > thanks > >> > sfora > >> > > >> > ------------------------------------------------------------------------- > >> > SF.Net email is sponsored by: > >> > Check out the new SourceForge.net Marketplace. > >> > It's the best place to buy or sell services > >> > for just about anything Open Source. > >> > > >> http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace > >> > _______________________________________________ > >> > Kgdb-bugreport mailing list > >> > Kgd...@li... > >> > https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport > >> > > >> > >> > >> > >> -- > >> Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory > >> Member, MIT Student Information Processing Board (SIPB) > >> URL: http://web.mit.edu/warlord/ PP-ASEL-IA N1NWH > >> warlord@MIT.EDU PGP key available > >> > >> > > > > > > -- > Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory > Member, MIT Student Information Processing Board (SIPB) > URL: http://web.mit.edu/warlord/ PP-ASEL-IA N1NWH > warlord@MIT.EDU PGP key available > > |
From: Derek A. <warlord@MIT.EDU> - 2007-12-17 16:59:41
|
Hi, Quoting sfora dim <sfo...@gm...>: > On 12/17/07, Derek Atkins <wa...@mi...> wrote: >> What .config did you use/start with? Did you check the physical >> start/align settings? Are they the same or are they different? > > Do you mean these settings: > CONFIG_PHYSICAL_ALIGN=0x100000 > CONFIG_PHYSICAL_START=0x100000 Yep, that's what I'm talking about. :( > ? > > Looks like they are the same... Indeed, so that's not the problem. Sorry, you're beyond me now. Good Luck, -derek >> >> -derek >> >> Quoting sfora dim <sfo...@gm...>: >> >> > On 12/17/07, Derek Atkins <wa...@mi...> wrote: >> >> Are you by chance running a Fedora kernel? If so the problem is >> >> the kernel physical start vs. physical align. >> > >> > Uhm, the target is FC8 but a kernel I have just compiled >> > (v2.6.23 branch of jason's kgdb git tree). >> > Host is Ubuntu 7.04. >> > >> > I am compiling on the host, and transfering the binary to the target >> > using NFS. >> > >> >> >> >> -derek >> >> >> >> Quoting sfora dim <sfo...@gm...>: >> >> >> >> > Hello all, >> >> > >> >> > I am trying to debug a remote kernel using kgdb. >> >> > host is x86, target is i386 (2.6.23) (under vmware), connection >> >> > completes fine. >> >> > Problem is - some of the symbols are plain wrong. >> >> > >> >> > For example - "p load_elf_binary" yields 0x802a4990 while that >> >> > function naturally resides above 0xc0000000. >> >> > >> >> > When I run gdb ./vmlinux inside the target itself, running the same "p" >> >> > command give me the correct result.. >> >> > >> >> > any Idea why this happens and how can I fix it ? >> >> > >> >> > Can I supply gdb the updated System.map or something ? >> >> > >> >> > thanks >> >> > sfora >> >> > >> >> > >> ------------------------------------------------------------------------- >> >> > SF.Net email is sponsored by: >> >> > Check out the new SourceForge.net Marketplace. >> >> > It's the best place to buy or sell services >> >> > for just about anything Open Source. >> >> > >> >> >> http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace >> >> > _______________________________________________ >> >> > Kgdb-bugreport mailing list >> >> > Kgd...@li... >> >> > https://lists.sourceforge.net/lists/listinfo/kgdb-bugreport >> >> > >> >> >> >> >> >> >> >> -- >> >> Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory >> >> Member, MIT Student Information Processing Board (SIPB) >> >> URL: http://web.mit.edu/warlord/ PP-ASEL-IA N1NWH >> >> warlord@MIT.EDU PGP key available >> >> >> >> >> > >> >> >> >> -- >> Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory >> Member, MIT Student Information Processing Board (SIPB) >> URL: http://web.mit.edu/warlord/ PP-ASEL-IA N1NWH >> warlord@MIT.EDU PGP key available >> >> > -- Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory Member, MIT Student Information Processing Board (SIPB) URL: http://web.mit.edu/warlord/ PP-ASEL-IA N1NWH warlord@MIT.EDU PGP key available |
From: sfora d. <sfo...@gm...> - 2007-12-17 17:17:25
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On 12/17/07, Derek Atkins <wa...@mi...> wrote: > Indeed, so that's not the problem. Sorry, you're beyond me now. > Good Luck, Thanks. The weird thing is that on the debugging host (ubuntu 7.04) i have gdb 6.6-debian, and this gdb shows the bad symbol address: but, on the target i have gdb 6.6-35.fc8rh, and that gdb shows the correct address! so on ubuntu i get a bad symbol while on fc8 i get a correct symbol (using the exact same binary) |
From: sfora d. <sfo...@gm...> - 2007-12-17 18:03:57
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Derek, thanks for the help. I have found the problem - it is a bug in debian's gdb-6.6 application. I have just compiled a fresh gdb-6.7 and it's ok... On 12/17/07, sfora dim <sfo...@gm...> wrote: > On 12/17/07, Derek Atkins <wa...@mi...> wrote: > > Indeed, so that's not the problem. Sorry, you're beyond me now. > > Good Luck, > > Thanks. > > The weird thing is that on the debugging host (ubuntu 7.04) i have gdb > 6.6-debian, > and this gdb shows the bad symbol address: > > but, on the target i have gdb 6.6-35.fc8rh, and that gdb shows the > correct address! > so on ubuntu i get a bad symbol while on fc8 i get a correct symbol > (using the exact same binary) > |