12:54 a.m.
__exception_text_start and __exception_text_end is used to group functions
and place according to linker script in such a way to achieve
kprobe blacklist. Linux commit b6e43c0e3129 ("arm64: remove __exception
annotations") has removed __exception_text_start and
__exception_text_end and uses NOKPROBE_SYMBOL() for blacklist kprobes.
So removing references of __exception_text_start and __exception_text_end
for ARM64.
Signed-off-by: Prabhakar Kushwaha <pkushwaha(a)marvell.com>
Cc: James Morse <james.morse(a)arm.com>
---
Changes for v2: Updated description and added CC-By
arm64.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)
diff --git a/arm64.c b/arm64.c
index 1b024a4..56ec088 100644
--- a/arm64.c
+++ b/arm64.c
@@ -673,8 +673,6 @@ arm64_dump_machdep_table(ulong arg)
fprintf(fp, " kimage_voffset: %016lx\n", ms->kimage_voffset);
}
fprintf(fp, " phys_offset: %lx\n", ms->phys_offset);
- fprintf(fp, "__exception_text_start: %lx\n", ms->__exception_text_start);
- fprintf(fp, " __exception_text_end: %lx\n", ms->__exception_text_end);
fprintf(fp, " __irqentry_text_start: %lx\n", ms->__irqentry_text_start);
fprintf(fp, " __irqentry_text_end: %lx\n", ms->__irqentry_text_end);
fprintf(fp, " exp_entry1_start: %lx\n", ms->exp_entry1_start);
@@ -1644,10 +1642,6 @@ arm64_stackframe_init(void)
machdep->machspec->kern_eframe_offset = SIZE(pt_regs);
}
- machdep->machspec->__exception_text_start =
- symbol_value("__exception_text_start");
- machdep->machspec->__exception_text_end =
- symbol_value("__exception_text_end");
if ((sp1 = kernel_symbol_search("__irqentry_text_start")) &&
(sp2 = kernel_symbol_search("__irqentry_text_end"))) {
machdep->machspec->__irqentry_text_start = sp1->value;
@@ -1861,9 +1855,7 @@ arm64_in_exception_text(ulong ptr)
{
struct machine_specific *ms = machdep->machspec;
- if ((ptr >= ms->__exception_text_start) &&
- (ptr < ms->__exception_text_end))
- return TRUE;
+ return TRUE;
if (ms->__irqentry_text_start && ms->__irqentry_text_end &&
((ptr >= ms->__irqentry_text_start) &&
--
2.17.1
8:01 a.m.
----- Original Message -----
__exception_text_start and __exception_text_end is used to group
functions
and place according to linker script in such a way to achieve
kprobe blacklist. Linux commit b6e43c0e3129 ("arm64: remove __exception
annotations") has removed __exception_text_start and
__exception_text_end and uses NOKPROBE_SYMBOL() for blacklist kprobes.
So removing references of __exception_text_start and __exception_text_end
for ARM64.
NAK for a couple of reasons...
First, they cannot be removed for backward-compatibility purposes, and secondly
an alternative method is required for arm64_back_trace_cmd() for handling
exception frames.
Dave
Signed-off-by: Prabhakar Kushwaha <pkushwaha(a)marvell.com>
Cc: James Morse <james.morse(a)arm.com>
---
Changes for v2: Updated description and added CC-By
arm64.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)
diff --git a/arm64.c b/arm64.c
index 1b024a4..56ec088 100644
--- a/arm64.c
+++ b/arm64.c
@@ -673,8 +673,6 @@ arm64_dump_machdep_table(ulong arg)
fprintf(fp, " kimage_voffset: %016lx\n", ms->kimage_voffset);
}
fprintf(fp, " phys_offset: %lx\n", ms->phys_offset);
- fprintf(fp, "__exception_text_start: %lx\n", ms->__exception_text_start);
- fprintf(fp, " __exception_text_end: %lx\n", ms->__exception_text_end);
fprintf(fp, " __irqentry_text_start: %lx\n", ms->__irqentry_text_start);
fprintf(fp, " __irqentry_text_end: %lx\n", ms->__irqentry_text_end);
fprintf(fp, " exp_entry1_start: %lx\n", ms->exp_entry1_start);
@@ -1644,10 +1642,6 @@ arm64_stackframe_init(void)
machdep->machspec->kern_eframe_offset = SIZE(pt_regs);
}
- machdep->machspec->__exception_text_start =
- symbol_value("__exception_text_start");
- machdep->machspec->__exception_text_end =
- symbol_value("__exception_text_end");
if ((sp1 = kernel_symbol_search("__irqentry_text_start")) &&
(sp2 = kernel_symbol_search("__irqentry_text_end"))) {
machdep->machspec->__irqentry_text_start = sp1->value;
@@ -1861,9 +1855,7 @@ arm64_in_exception_text(ulong ptr)
{
struct machine_specific *ms = machdep->machspec;
- if ((ptr >= ms->__exception_text_start) &&
- (ptr < ms->__exception_text_end))
- return TRUE;
+ return TRUE;
if (ms->__irqentry_text_start && ms->__irqentry_text_end &&
((ptr >= ms->__irqentry_text_start) &&
--
2.17.1
--
Crash-utility mailing list
Crash-utility(a)redhat.com
https://www.redhat.com/mailman/listinfo/crash-utility
8:18 a.m.
On Mon, Dec 23, 2019 at 7:32 PM Dave Anderson <anderson(a)redhat.com> wrote:
----- Original Message -----
> __exception_text_start and __exception_text_end is used to group functions
> and place according to linker script in such a way to achieve
> kprobe blacklist. Linux commit b6e43c0e3129 ("arm64: remove __exception
> annotations") has removed __exception_text_start and
> __exception_text_end and uses NOKPROBE_SYMBOL() for blacklist kprobes.
>
> So removing references of __exception_text_start and __exception_text_end
> for ARM64.
NAK for a couple of reasons...
First, they cannot be removed for backward-compatibility purposes, and secondly
an alternative method is required for arm64_back_trace_cmd() for handling
exception frames.
We are getting following error with crash tool with latest kernel.
crash: cannot resolve "__exception_text_start" error
it is because of Linux commit b6e43c0e3129 which removes
__exception_text_start and __exception_text_end.
We need to find alternate way of fixing it.
--pk
1:38 p.m.
On Mon, Dec 23, 2019 at 7:49 PM Prabhakar Kushwaha
<prabhakar.pkin(a)gmail.com> wrote:
On Mon, Dec 23, 2019 at 7:32 PM Dave Anderson <anderson(a)redhat.com> wrote:
>
>
>
> ----- Original Message -----
> > __exception_text_start and __exception_text_end is used to group functions
> > and place according to linker script in such a way to achieve
> > kprobe blacklist. Linux commit b6e43c0e3129 ("arm64: remove __exception
> > annotations") has removed __exception_text_start and
> > __exception_text_end and uses NOKPROBE_SYMBOL() for blacklist kprobes.
> >
> > So removing references of __exception_text_start and __exception_text_end
> > for ARM64.
>
> NAK for a couple of reasons...
>
> First, they cannot be removed for backward-compatibility purposes, and secondly
> an alternative method is required for arm64_back_trace_cmd() for handling
> exception frames.
>
We are getting following error with crash tool with latest kernel.
crash: cannot resolve "__exception_text_start" error
it is because of Linux commit b6e43c0e3129 which removes
__exception_text_start and __exception_text_end.
We need to find alternate way of fixing it.
I cannot seem to remember reproducing this issue with crash with
latest kernel on my arm64 boards.
Can you be more specific on the exact kernel version and the crash
command you used, just to be sure we are able to reproduce the same?
Thanks,
Bhupesh
10:09 p.m.
On Tue, Dec 24, 2019 at 1:09 AM Bhupesh Sharma <bhsharma(a)redhat.com> wrote:
On Mon, Dec 23, 2019 at 7:49 PM Prabhakar Kushwaha
<prabhakar.pkin(a)gmail.com> wrote:
>
> On Mon, Dec 23, 2019 at 7:32 PM Dave Anderson <anderson(a)redhat.com> wrote:
> >
> >
> >
> > ----- Original Message -----
> > > __exception_text_start and __exception_text_end is used to group
functions
> > > and place according to linker script in such a way to achieve
> > > kprobe blacklist. Linux commit b6e43c0e3129 ("arm64: remove
__exception
> > > annotations") has removed __exception_text_start and
> > > __exception_text_end and uses NOKPROBE_SYMBOL() for blacklist kprobes.
> > >
> > > So removing references of __exception_text_start and __exception_text_end
> > > for ARM64.
> >
> > NAK for a couple of reasons...
> >
> > First, they cannot be removed for backward-compatibility purposes, and
secondly
> > an alternative method is required for arm64_back_trace_cmd() for handling
> > exception frames.
> >
>
> We are getting following error with crash tool with latest kernel.
> crash: cannot resolve "__exception_text_start" error
>
> it is because of Linux commit b6e43c0e3129 which removes
> __exception_text_start and __exception_text_end.
> We need to find alternate way of fixing it.
I cannot seem to remember reproducing this issue with crash with
latest kernel on my arm64 boards.
Can you be more specific on the exact kernel version and the crash
command you used, just to be sure we are able to reproduce the same?
We are seeing this issue on Thuder X platform (arm64).
Please find details of commit id.
A) crash tool: https://github.com/crash-utility/crash.git
commit: af7f78dc501b8acf7fee3f924f69e93513d0a74b (Fix for the "log -a"
option.)
B) Linux: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit: 46cf053efec6a3a5f343fead837777efe8252a46 (Linux 5.5-rc3)
C) Kexec: https://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git
commit: bd077966e2b9041c24df5b689e67670f02be7b0d (kexec-tools: Fix
conversion overflow when compiling on 32-bit platforms)
Logs
root@ubuntu$ ./crash /proc/vmcore /usr/src/tovards/linux/vmlinux
crash 7.2.7++
Copyright (C) 2002-2019 Red Hat, Inc.
Copyright (C) 2004, 2005, 2006, 2010 IBM Corporation
Copyright (C) 1999-2006 Hewlett-Packard Co
Copyright (C) 2005, 2006, 2011, 2012 Fujitsu Limited
Copyright (C) 2006, 2007 VA Linux Systems Japan K.K.
Copyright (C) 2005, 2011 NEC Corporation
Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc.
Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
This program is free software, covered by the GNU General Public License,
and you are welcome to change it and/or distribute copies of it under
certain conditions. Enter "help copying" to see the conditions.
This program has absolutely no warranty. Enter "help warranty" for details.
vmcoreinfo : vabits_actual: 48
GNU gdb (GDB) 7.6
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "aarch64-unknown-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
crash: cannot resolve "__exception_text_start"
--pk
10:24 p.m.
Dear Bhupesh,
On Tue, Dec 24, 2019 at 9:39 AM Prabhakar Kushwaha
<prabhakar.pkin(a)gmail.com> wrote:
On Tue, Dec 24, 2019 at 1:09 AM Bhupesh Sharma <bhsharma(a)redhat.com> wrote:
>
> On Mon, Dec 23, 2019 at 7:49 PM Prabhakar Kushwaha
> <prabhakar.pkin(a)gmail.com> wrote:
> >
> > On Mon, Dec 23, 2019 at 7:32 PM Dave Anderson <anderson(a)redhat.com>
wrote:
> > >
> > >
> > >
> > > ----- Original Message -----
> > > > __exception_text_start and __exception_text_end is used to group
functions
> > > > and place according to linker script in such a way to achieve
> > > > kprobe blacklist. Linux commit b6e43c0e3129 ("arm64: remove
__exception
> > > > annotations") has removed __exception_text_start and
> > > > __exception_text_end and uses NOKPROBE_SYMBOL() for blacklist
kprobes.
> > > >
> > > > So removing references of __exception_text_start and
__exception_text_end
> > > > for ARM64.
> > >
> > > NAK for a couple of reasons...
> > >
> > > First, they cannot be removed for backward-compatibility purposes, and
secondly
> > > an alternative method is required for arm64_back_trace_cmd() for handling
> > > exception frames.
> > >
> >
> > We are getting following error with crash tool with latest kernel.
> > crash: cannot resolve "__exception_text_start" error
> >
> > it is because of Linux commit b6e43c0e3129 which removes
> > __exception_text_start and __exception_text_end.
> > We need to find alternate way of fixing it.
>
> I cannot seem to remember reproducing this issue with crash with
> latest kernel on my arm64 boards.
> Can you be more specific on the exact kernel version and the crash
> command you used, just to be sure we are able to reproduce the same?
>
We are seeing this issue on Thuder X platform (arm64).
Please find details of commit id.
A) crash tool: https://github.com/crash-utility/crash.git
commit: af7f78dc501b8acf7fee3f924f69e93513d0a74b (Fix for the "log -a"
option.)
B) Linux: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
commit: 46cf053efec6a3a5f343fead837777efe8252a46 (Linux 5.5-rc3)
C) Kexec: https://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git
commit: bd077966e2b9041c24df5b689e67670f02be7b0d (kexec-tools: Fix
conversion overflow when compiling on 32-bit platforms)
Logs
root@ubuntu$ ./crash /proc/vmcore /usr/src/tovards/linux/vmlinux
crash 7.2.7++
Copyright (C) 2002-2019 Red Hat, Inc.
Copyright (C) 2004, 2005, 2006, 2010 IBM Corporation
Copyright (C) 1999-2006 Hewlett-Packard Co
Copyright (C) 2005, 2006, 2011, 2012 Fujitsu Limited
Copyright (C) 2006, 2007 VA Linux Systems Japan K.K.
Copyright (C) 2005, 2011 NEC Corporation
Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc.
Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
This program is free software, covered by the GNU General Public License,
and you are welcome to change it and/or distribute copies of it under
certain conditions. Enter "help copying" to see the conditions.
This program has absolutely no warranty. Enter "help warranty" for details.
vmcoreinfo : vabits_actual: 48
GNU gdb (GDB) 7.6
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "aarch64-unknown-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
crash: cannot resolve "__exception_text_start"
i hope you got sometime to reproduce this issue.
It can also be seen on Linux 5.5-rc4 tag
(fd6988496e79a6a4bdb514a4655d2920209eb85d).
crash-util commit 5e975dd8c817ea6aea35e1e15b83c378aee9c136 (HEAD ->
master, origin/master, origin/HEAD)
--pk
3:01 p.m.
Hi Prabhakar,
On Mon, Dec 30, 2019 at 9:55 AM Prabhakar Kushwaha
<prabhakar.pkin(a)gmail.com> wrote:
Dear Bhupesh,
On Tue, Dec 24, 2019 at 9:39 AM Prabhakar Kushwaha
<prabhakar.pkin(a)gmail.com> wrote:
>
> On Tue, Dec 24, 2019 at 1:09 AM Bhupesh Sharma <bhsharma(a)redhat.com> wrote:
> >
> > On Mon, Dec 23, 2019 at 7:49 PM Prabhakar Kushwaha
> > <prabhakar.pkin(a)gmail.com> wrote:
> > >
> > > On Mon, Dec 23, 2019 at 7:32 PM Dave Anderson <anderson(a)redhat.com>
wrote:
> > > >
> > > >
> > > >
> > > > ----- Original Message -----
> > > > > __exception_text_start and __exception_text_end is used to group
functions
> > > > > and place according to linker script in such a way to achieve
> > > > > kprobe blacklist. Linux commit b6e43c0e3129 ("arm64: remove
__exception
> > > > > annotations") has removed __exception_text_start and
> > > > > __exception_text_end and uses NOKPROBE_SYMBOL() for blacklist
kprobes.
> > > > >
> > > > > So removing references of __exception_text_start and
__exception_text_end
> > > > > for ARM64.
> > > >
> > > > NAK for a couple of reasons...
> > > >
> > > > First, they cannot be removed for backward-compatibility purposes,
and secondly
> > > > an alternative method is required for arm64_back_trace_cmd() for
handling
> > > > exception frames.
> > > >
> > >
> > > We are getting following error with crash tool with latest kernel.
> > > crash: cannot resolve "__exception_text_start" error
> > >
> > > it is because of Linux commit b6e43c0e3129 which removes
> > > __exception_text_start and __exception_text_end.
> > > We need to find alternate way of fixing it.
> >
> > I cannot seem to remember reproducing this issue with crash with
> > latest kernel on my arm64 boards.
> > Can you be more specific on the exact kernel version and the crash
> > command you used, just to be sure we are able to reproduce the same?
> >
>
> We are seeing this issue on Thuder X platform (arm64).
>
> Please find details of commit id.
> A) crash tool: https://github.com/crash-utility/crash.git
> commit: af7f78dc501b8acf7fee3f924f69e93513d0a74b (Fix for the "log -a"
option.)
>
> B) Linux: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> commit: 46cf053efec6a3a5f343fead837777efe8252a46 (Linux 5.5-rc3)
>
> C) Kexec: https://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git
> commit: bd077966e2b9041c24df5b689e67670f02be7b0d (kexec-tools: Fix
> conversion overflow when compiling on 32-bit platforms)
>
>
> Logs
> root@ubuntu$ ./crash /proc/vmcore /usr/src/tovards/linux/vmlinux
>
> crash 7.2.7++
> Copyright (C) 2002-2019 Red Hat, Inc.
> Copyright (C) 2004, 2005, 2006, 2010 IBM Corporation
> Copyright (C) 1999-2006 Hewlett-Packard Co
> Copyright (C) 2005, 2006, 2011, 2012 Fujitsu Limited
> Copyright (C) 2006, 2007 VA Linux Systems Japan K.K.
> Copyright (C) 2005, 2011 NEC Corporation
> Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc.
> Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
> This program is free software, covered by the GNU General Public License,
> and you are welcome to change it and/or distribute copies of it under
> certain conditions. Enter "help copying" to see the conditions.
> This program has absolutely no warranty. Enter "help warranty" for
details.
>
> vmcoreinfo : vabits_actual: 48
> GNU gdb (GDB) 7.6
> Copyright (C) 2013 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law. Type "show
copying"
> and "show warranty" for details.
> This GDB was configured as "aarch64-unknown-linux-gnu".
> For bug reporting instructions, please see:
> <http://www.gnu.org/software/gdb/bugs/>...
>
> crash: cannot resolve "__exception_text_start"
>
i hope you got sometime to reproduce this issue.
It can also be seen on Linux 5.5-rc4 tag
(fd6988496e79a6a4bdb514a4655d2920209eb85d).
crash-util commit 5e975dd8c817ea6aea35e1e15b83c378aee9c136 (HEAD ->
master, origin/master, origin/HEAD)
I was able to reproduce the issue with latest Linus's tree. I am
working on a patch (as per Dave's suggestion) to fix backward
compatibility as well as 'arm64_back_trace_cmd()' (bt command support)
and will post it out soon (I am hoping to post out a version after the
new year break).
Thanks and a Happy New Year,
Bhupesh
3:18 p.m.
Hi Prabhakar,
On Mon, Dec 30, 2019 at 9:55 AM Prabhakar Kushwaha
<prabhakar.pkin(a)gmail.com> wrote:
>
> Dear Bhupesh,
>
> On Tue, Dec 24, 2019 at 9:39 AM Prabhakar Kushwaha
> <prabhakar.pkin(a)gmail.com> wrote:
> >
> > On Tue, Dec 24, 2019 at 1:09 AM Bhupesh Sharma <bhsharma(a)redhat.com>
> wrote:
> > >
> > > On Mon, Dec 23, 2019 at 7:49 PM Prabhakar Kushwaha
> > > <prabhakar.pkin(a)gmail.com> wrote:
> > > >
> > > > On Mon, Dec 23, 2019 at 7:32 PM Dave Anderson
> <anderson(a)redhat.com> wrote:
> > > > >
> > > > >
> > > > >
> > > > > ----- Original Message -----
> > > > > > __exception_text_start and __exception_text_end is used to
> group functions
> > > > > > and place according to linker script in such a way to
achieve
> > > > > > kprobe blacklist. Linux commit b6e43c0e3129 ("arm64:
remove
> __exception
> > > > > > annotations") has removed __exception_text_start and
> > > > > > __exception_text_end and uses NOKPROBE_SYMBOL() for
blacklist
> kprobes.
> > > > > >
> > > > > > So removing references of __exception_text_start and
> __exception_text_end
> > > > > > for ARM64.
> > > > >
> > > > > NAK for a couple of reasons...
> > > > >
> > > > > First, they cannot be removed for backward-compatibility
> purposes, and secondly
> > > > > an alternative method is required for arm64_back_trace_cmd() for
> handling
> > > > > exception frames.
> > > > >
> > > >
> > > > We are getting following error with crash tool with latest kernel.
> > > > crash: cannot resolve "__exception_text_start" error
> > > >
> > > > it is because of Linux commit b6e43c0e3129 which removes
> > > > __exception_text_start and __exception_text_end.
> > > > We need to find alternate way of fixing it.
> > >
> > > I cannot seem to remember reproducing this issue with crash with
> > > latest kernel on my arm64 boards.
> > > Can you be more specific on the exact kernel version and the crash
> > > command you used, just to be sure we are able to reproduce the same?
> > >
> >
> > We are seeing this issue on Thuder X platform (arm64).
> >
> > Please find details of commit id.
> > A) crash tool: https://github.com/crash-utility/crash.git
> > commit: af7f78dc501b8acf7fee3f924f69e93513d0a74b (Fix for the "log
> -a" option.)
> >
> > B) Linux:
> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> > commit: 46cf053efec6a3a5f343fead837777efe8252a46 (Linux 5.5-rc3)
> >
> > C) Kexec:
> https://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git
> > commit: bd077966e2b9041c24df5b689e67670f02be7b0d (kexec-tools: Fix
> > conversion overflow when compiling on 32-bit platforms)
> >
> >
> > Logs
> > root@ubuntu$ ./crash /proc/vmcore /usr/src/tovards/linux/vmlinux
> >
> > crash 7.2.7++
> > Copyright (C) 2002-2019 Red Hat, Inc.
> > Copyright (C) 2004, 2005, 2006, 2010 IBM Corporation
> > Copyright (C) 1999-2006 Hewlett-Packard Co
> > Copyright (C) 2005, 2006, 2011, 2012 Fujitsu Limited
> > Copyright (C) 2006, 2007 VA Linux Systems Japan K.K.
> > Copyright (C) 2005, 2011 NEC Corporation
> > Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc.
> > Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
> > This program is free software, covered by the GNU General Public
> License,
> > and you are welcome to change it and/or distribute copies of it under
> > certain conditions. Enter "help copying" to see the conditions.
> > This program has absolutely no warranty. Enter "help warranty" for
> details.
> >
> > vmcoreinfo : vabits_actual: 48
> > GNU gdb (GDB) 7.6
> > Copyright (C) 2013 Free Software Foundation, Inc.
> > License GPLv3+: GNU GPL version 3 or later
> <http://gnu.org/licenses/gpl.html>
> > This is free software: you are free to change and redistribute it.
> > There is NO WARRANTY, to the extent permitted by law. Type "show
> copying"
> > and "show warranty" for details.
> > This GDB was configured as "aarch64-unknown-linux-gnu".
> > For bug reporting instructions, please see:
> > <http://www.gnu.org/software/gdb/bugs/>...
> >
> > crash: cannot resolve "__exception_text_start"
> >
>
> i hope you got sometime to reproduce this issue.
> It can also be seen on Linux 5.5-rc4 tag
> (fd6988496e79a6a4bdb514a4655d2920209eb85d).
>
> crash-util commit 5e975dd8c817ea6aea35e1e15b83c378aee9c136 (HEAD ->
> master, origin/master, origin/HEAD)
I was able to reproduce the issue with latest Linus's tree. I am
working on a patch (as per Dave's suggestion) to fix backward
compatibility as well as 'arm64_back_trace_cmd()' (bt command support)
and will post it out soon (I am hoping to post out a version after the
new year break).
Thanks and a Happy New Year,
Bhupesh
Thanks Bhupesh, I'm also out until next week.
And yeah, for 5.5 and later kernels it looks like
arm64_in_exception_text() will have to check the incoming
address's symbol name against the set of exception handler
symbol names. The older kernels can still utilize the handy
text range between __exception_text_start/__exception_text_end.
Kind of a pain, but I don't know what the alternative would be.
Dave
2:38 p.m.
----- Original Message -----
> Hi Prabhakar,
>
> On Mon, Dec 30, 2019 at 9:55 AM Prabhakar Kushwaha
> <prabhakar.pkin(a)gmail.com> wrote:
>>
>> Dear Bhupesh,
>>
>> On Tue, Dec 24, 2019 at 9:39 AM Prabhakar Kushwaha
>> <prabhakar.pkin(a)gmail.com> wrote:
>> >
>> > On Tue, Dec 24, 2019 at 1:09 AM Bhupesh Sharma <bhsharma(a)redhat.com>
>> wrote:
>> > >
>> > > On Mon, Dec 23, 2019 at 7:49 PM Prabhakar Kushwaha
>> > > <prabhakar.pkin(a)gmail.com> wrote:
>> > > >
>> > > > On Mon, Dec 23, 2019 at 7:32 PM Dave Anderson
>> <anderson(a)redhat.com> wrote:
>> > > > >
>> > > > >
>> > > > >
>> > > > > ----- Original Message -----
>> > > > > > __exception_text_start and __exception_text_end is used
to
>> group functions
>> > > > > > and place according to linker script in such a way to
achieve
>> > > > > > kprobe blacklist. Linux commit b6e43c0e3129
("arm64: remove
>> __exception
>> > > > > > annotations") has removed __exception_text_start
and
>> > > > > > __exception_text_end and uses NOKPROBE_SYMBOL() for
blacklist
>> kprobes.
>> > > > > >
>> > > > > > So removing references of __exception_text_start and
>> __exception_text_end
>> > > > > > for ARM64.
>> > > > >
>> > > > > NAK for a couple of reasons...
>> > > > >
>> > > > > First, they cannot be removed for backward-compatibility
>> purposes, and secondly
>> > > > > an alternative method is required for arm64_back_trace_cmd()
for
>> handling
>> > > > > exception frames.
>> > > > >
>> > > >
>> > > > We are getting following error with crash tool with latest
kernel.
>> > > > crash: cannot resolve "__exception_text_start" error
>> > > >
>> > > > it is because of Linux commit b6e43c0e3129 which removes
>> > > > __exception_text_start and __exception_text_end.
>> > > > We need to find alternate way of fixing it.
>> > >
>> > > I cannot seem to remember reproducing this issue with crash with
>> > > latest kernel on my arm64 boards.
>> > > Can you be more specific on the exact kernel version and the crash
>> > > command you used, just to be sure we are able to reproduce the same?
>> > >
>> >
>> > We are seeing this issue on Thuder X platform (arm64).
>> >
>> > Please find details of commit id.
>> > A) crash tool: https://github.com/crash-utility/crash.git
>> > commit: af7f78dc501b8acf7fee3f924f69e93513d0a74b (Fix for the "log
>> -a" option.)
>> >
>> > B) Linux:
>> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
>> > commit: 46cf053efec6a3a5f343fead837777efe8252a46 (Linux 5.5-rc3)
>> >
>> > C) Kexec:
>> https://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git
>> > commit: bd077966e2b9041c24df5b689e67670f02be7b0d (kexec-tools: Fix
>> > conversion overflow when compiling on 32-bit platforms)
>> >
>> >
>> > Logs
>> > root@ubuntu$ ./crash /proc/vmcore /usr/src/tovards/linux/vmlinux
>> >
>> > crash 7.2.7++
>> > Copyright (C) 2002-2019 Red Hat, Inc.
>> > Copyright (C) 2004, 2005, 2006, 2010 IBM Corporation
>> > Copyright (C) 1999-2006 Hewlett-Packard Co
>> > Copyright (C) 2005, 2006, 2011, 2012 Fujitsu Limited
>> > Copyright (C) 2006, 2007 VA Linux Systems Japan K.K.
>> > Copyright (C) 2005, 2011 NEC Corporation
>> > Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc.
>> > Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc.
>> > This program is free software, covered by the GNU General Public
>> License,
>> > and you are welcome to change it and/or distribute copies of it under
>> > certain conditions. Enter "help copying" to see the conditions.
>> > This program has absolutely no warranty. Enter "help warranty"
for
>> details.
>> >
>> > vmcoreinfo : vabits_actual: 48
>> > GNU gdb (GDB) 7.6
>> > Copyright (C) 2013 Free Software Foundation, Inc.
>> > License GPLv3+: GNU GPL version 3 or later
>> <http://gnu.org/licenses/gpl.html>
>> > This is free software: you are free to change and redistribute it.
>> > There is NO WARRANTY, to the extent permitted by law. Type "show
>> copying"
>> > and "show warranty" for details.
>> > This GDB was configured as "aarch64-unknown-linux-gnu".
>> > For bug reporting instructions, please see:
>> > <http://www.gnu.org/software/gdb/bugs/>...
>> >
>> > crash: cannot resolve "__exception_text_start"
>> >
>>
>> i hope you got sometime to reproduce this issue.
>> It can also be seen on Linux 5.5-rc4 tag
>> (fd6988496e79a6a4bdb514a4655d2920209eb85d).
>>
>> crash-util commit 5e975dd8c817ea6aea35e1e15b83c378aee9c136 (HEAD ->
>> master, origin/master, origin/HEAD)
>
> I was able to reproduce the issue with latest Linus's tree. I am
> working on a patch (as per Dave's suggestion) to fix backward
> compatibility as well as 'arm64_back_trace_cmd()' (bt command support)
> and will post it out soon (I am hoping to post out a version after the
> new year break).
>
> Thanks and a Happy New Year,
> Bhupesh
>
Thanks Bhupesh, I'm also out until next week.
And yeah, for 5.5 and later kernels it looks like
arm64_in_exception_text() will have to check the incoming
address's symbol name against the set of exception handler
symbol names. The older kernels can still utilize the handy
text range between __exception_text_start/__exception_text_end.
Kind of a pain, but I don't know what the alternative would be.
Dave
Hi Bhupesh,
Here's what I'm thinking... (attached patch)
Thanks,
Dave
1777
days inactive
1793
days old
devel@lists.crash-utility.osci.io
8 comments
5 participants
participants (5)
-
Bhupesh Sharma -
Dave Anderson -
Dave Anderson -
Prabhakar Kushwaha -
Prabhakar Kushwaha