kdb: Remove unused flags stack

kdb_restore_flags() and kdb_save_flags() were added in 2010 by
commit 5d5314d6795f ("kdb: core for kgdb back end (1 of 2)")
but have remained unused.

Remove them, and

kdb: Remove unused flags stack

kdb_restore_flags() and kdb_save_flags() were added in 2010 by
commit 5d5314d6795f ("kdb: core for kgdb back end (1 of 2)")
but have remained unused.

Remove them, and their associated storage.

Signed-off-by: Dr. David Alan Gilbert <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Daniel Thompson (RISCstar) <[email protected]>

show more ...

kdb: use kmap_local_page()

Use kmap_local_page() instead of kmap_atomic() which has been deprecated.

Signed-off-by: Zhang Heng <[email protected]>
Reviewed-by: Douglas Anderson <dianders@chromiu

kdb: use kmap_local_page()

Use kmap_local_page() instead of kmap_atomic() which has been deprecated.

Signed-off-by: Zhang Heng <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Daniel Thompson (RISCstar) <[email protected]>

show more ...

module: Move kdb module related code out of main kdb code

No functional change.

This patch migrates the kdb 'lsmod' command support out of main
kdb code into its own file under kernel/module. In ad

module: Move kdb module related code out of main kdb code

No functional change.

This patch migrates the kdb 'lsmod' command support out of main
kdb code into its own file under kernel/module. In addition to
the above, a minor style warning i.e. missing a blank line after
declarations, was resolved too. The new file was added to
MAINTAINERS. Finally we remove linux/module.h as it is entirely
redundant.

Reviewed-by: Daniel Thompson <[email protected]>
Acked-by: Daniel Thompson <[email protected]>
Signed-off-by: Aaron Tomlin <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>

show more ...

kdb: Fix the putarea helper function

Currently kdb_putarea_size() uses copy_from_kernel_nofault() to write *to*
arbitrary kernel memory. This is obviously wrong and means the memory
modify ('mm') co

kdb: Fix the putarea helper function

Currently kdb_putarea_size() uses copy_from_kernel_nofault() to write *to*
arbitrary kernel memory. This is obviously wrong and means the memory
modify ('mm') command is a serious risk to debugger stability: if we poke
to a bad address we'll double-fault and lose our debug session.

Fix this the (very) obvious way.

Note that there are two Fixes: tags because the API was renamed and this
patch will only trivially backport as far as the rename (and this is
probably enough). Nevertheless Christoph's rename did not introduce this
problem so I wanted to record that!

Fixes: fe557319aa06 ("maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault")
Fixes: 5d5314d6795f ("kdb: core for kgdb back end (1 of 2)")
Signed-off-by: Daniel Thompson <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

kdb: Adopt scheduler's task classification

Currently kdb contains some open-coded routines to generate a summary
character for each task. This code currently issues warnings, is
almost certainly bro

kdb: Adopt scheduler's task classification

Currently kdb contains some open-coded routines to generate a summary
character for each task. This code currently issues warnings, is
almost certainly broken and won't make sense to any kernel dev who
has ever used /proc to examine task states.

Fix both the warning and the potential for confusion by adopting the
scheduler's task classification. Whilst doing this we also simplify the
filtering by using mask strings directly (which means we don't have to
guess all the characters the scheduler might give us).

Unfortunately we can't quite match the scheduler classification completely.
We add four extra states: - for idle loops and i, m and s for sleeping
system daemons (which means kthreads in one of the I, M and S states).
These extra states are used to manage the filters for tools to make the
output of ps and bta less noisy.

Note: The Fixes below is the last point the original dubious code was
moved; it was not introduced by that patch. However it gives us
the last point to which this patch can be easily backported.
Happily that should be enough to cover the introduction of
CONFIG_WERROR!

Fixes: 2f064a59a11f ("sched: Change task_struct::state")
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Douglas Anderson <[email protected]>
Signed-off-by: Daniel Thompson <[email protected]>

show more ...

isystem: trim/fixup stdarg.h and other headers

Delete/fixup few includes in anticipation of global -isystem compile
option removal.

Note: crypto/aegis128-neon-inner.c keeps <stddef.h> due to redefi

isystem: trim/fixup stdarg.h and other headers

Delete/fixup few includes in anticipation of global -isystem compile
option removal.

Note: crypto/aegis128-neon-inner.c keeps <stddef.h> due to redefinition
of uintptr_t error (one definition comes from <stddef.h>, another from
<linux/types.h>).

Signed-off-by: Alexey Dobriyan <[email protected]>
Signed-off-by: Masahiro Yamada <[email protected]>

show more ...

kdb: Get rid of custom debug heap allocator

Currently the only user for debug heap is kdbnearsym() which can be
modified to rather use statically allocated buffer for symbol name as
per it's current

kdb: Get rid of custom debug heap allocator

Currently the only user for debug heap is kdbnearsym() which can be
modified to rather use statically allocated buffer for symbol name as
per it's current usage. So do that and hence remove custom debug heap
allocator.

Note that this change puts a restriction on kdbnearsym() callers to
carefully use shared namebuf such that a caller should consume the symbol
returned immediately prior to another call to fetch a different symbol.

Also, this change uses standard KSYM_NAME_LEN macro for namebuf
allocation instead of local variable: knt1_size which should avoid any
conflicts caused by changes to KSYM_NAME_LEN macro value.

This change has been tested using kgdbtest on arm64 which doesn't show
any regressions.

Suggested-by: Daniel Thompson <[email protected]>
Signed-off-by: Sumit Garg <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Daniel Thompson <[email protected]>

show more ...

sched: Change task_struct::state

Change the type and name of task_struct::state. Drop the volatile and
shrink it to an 'unsigned int'. Rename it in order to find all uses
such that we can use READ_O

sched: Change task_struct::state

Change the type and name of task_struct::state. Drop the volatile and
shrink it to an 'unsigned int'. Rename it in order to find all uses
such that we can use READ_ONCE/WRITE_ONCE as appropriate.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Daniel Bristot de Oliveira <[email protected]>
Acked-by: Will Deacon <[email protected]>
Acked-by: Daniel Thompson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

show more ...

kdb: Remove redundant function definitions/prototypes

Cleanup kdb code to get rid of unused function definitions/prototypes.

Signed-off-by: Sumit Garg <[email protected]>
Link: https://lore.ker

kdb: Remove redundant function definitions/prototypes

Cleanup kdb code to get rid of unused function definitions/prototypes.

Signed-off-by: Sumit Garg <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Douglas Anderson <[email protected]>
Signed-off-by: Daniel Thompson <[email protected]>

show more ...

kdb: kdb_support: Fix debugging information problem

There are several common patterns.

0:
kdb_printf("...",...);

which is the normal one.

1:
kdb_printf("%s: "...,__func__,...)

We

kdb: kdb_support: Fix debugging information problem

There are several common patterns.

0:
kdb_printf("...",...);

which is the normal one.

1:
kdb_printf("%s: "...,__func__,...)

We could improve '1' to this :

#define kdb_func_printf(format, args...) \
kdb_printf("%s: " format, __func__, ## args)

2:
if(KDB_DEBUG(AR))
kdb_printf("%s "...,__func__,...);

We could improve '2' to this :
#define kdb_dbg_printf(mask, format, args...) \
do { \
if (KDB_DEBUG(mask)) \
kdb_func_printf(format, ## args); \
} while (0)

In addition, we changed the format code of size_t to %zu.

Signed-off-by: Stephen Zhang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Douglas Anderson <[email protected]>
[[email protected]: Minor typo and line length fixes in the
patch description]
Signed-off-by: Daniel Thompson <[email protected]>

show more ...

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through mar

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <[email protected]>

show more ...

maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault

Better describe what these functions do.

Suggested-by: Linus Torvalds <[email protected]>
Signed-off-by: Chris

maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault

Better describe what these functions do.

Suggested-by: Linus Torvalds <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

show more ...

kdb: kdb_support: replace strcpy() by strscpy()

The strcpy() function is being deprecated. Replace it by the safer
strscpy() and fix the following Coverity warning:

"You might overrun the 129-chara

kdb: kdb_support: replace strcpy() by strscpy()

The strcpy() function is being deprecated. Replace it by the safer
strscpy() and fix the following Coverity warning:

"You might overrun the 129-character fixed-size string ks_namebuf
by copying name without checking the length."

Addresses-Coverity-ID: 138995 ("Copy into fixed size buffer")
Signed-off-by: Gustavo A. R. Silva <[email protected]>
Signed-off-by: Daniel Thompson <[email protected]>

show more ...

kdb: kdb_support: mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Notice that in this particular case

kdb: kdb_support: mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Notice that in this particular case, I replaced the code comments with
a proper "fall through" annotation, which is what GCC is expecting
to find.

Signed-off-by: Gustavo A. R. Silva <[email protected]>
Reviewed-by: Daniel Thompson <[email protected]>
Signed-off-by: Daniel Thompson <[email protected]>

show more ...

kdb: Use strscpy with destination buffer size

gcc 8.1.0 warns with:

kernel/debug/kdb/kdb_support.c: In function ‘kallsyms_symbol_next’:
kernel/debug/kdb/kdb_support.c:239:4: warning: ‘strncpy’ spec

kdb: Use strscpy with destination buffer size

gcc 8.1.0 warns with:

kernel/debug/kdb/kdb_support.c: In function ‘kallsyms_symbol_next’:
kernel/debug/kdb/kdb_support.c:239:4: warning: ‘strncpy’ specified bound depends on the length of the source argument [-Wstringop-overflow=]
strncpy(prefix_name, name, strlen(name)+1);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
kernel/debug/kdb/kdb_support.c:239:31: note: length computed here

Use strscpy() with the destination buffer size, and use ellipses when
displaying truncated symbols.

v2: Use strscpy()

Signed-off-by: Prarit Bhargava <[email protected]>
Cc: Jonathan Toppins <[email protected]>
Cc: Jason Wessel <[email protected]>
Cc: Daniel Thompson <[email protected]>
Cc: [email protected]
Reviewed-by: Daniel Thompson <[email protected]>
Signed-off-by: Daniel Thompson <[email protected]>

show more ...

kdb: print real address of pointers instead of hashed addresses

Since commit ad67b74d2469 ("printk: hash addresses printed with %p"),
all pointers printed with %p are printed with hashed addresses
i

kdb: print real address of pointers instead of hashed addresses

Since commit ad67b74d2469 ("printk: hash addresses printed with %p"),
all pointers printed with %p are printed with hashed addresses
instead of real addresses in order to avoid leaking addresses in
dmesg and syslog. But this applies to kdb too, with is unfortunate:

Entering kdb (current=0x(ptrval), pid 329) due to Keyboard Entry
kdb> ps
15 sleeping system daemon (state M) processes suppressed,
use 'ps A' to see all.
Task Addr Pid Parent [*] cpu State Thread Command
0x(ptrval) 329 328 1 0 R 0x(ptrval) *sh

0x(ptrval) 1 0 0 0 S 0x(ptrval) init
0x(ptrval) 3 2 0 0 D 0x(ptrval) rcu_gp
0x(ptrval) 4 2 0 0 D 0x(ptrval) rcu_par_gp
0x(ptrval) 5 2 0 0 D 0x(ptrval) kworker/0:0
0x(ptrval) 6 2 0 0 D 0x(ptrval) kworker/0:0H
0x(ptrval) 7 2 0 0 D 0x(ptrval) kworker/u2:0
0x(ptrval) 8 2 0 0 D 0x(ptrval) mm_percpu_wq
0x(ptrval) 10 2 0 0 D 0x(ptrval) rcu_preempt

The whole purpose of kdb is to debug, and for debugging real addresses
need to be known. In addition, data displayed by kdb doesn't go into
dmesg.

This patch replaces all %p by %px in kdb in order to display real
addresses.

Fixes: ad67b74d2469 ("printk: hash addresses printed with %p")
Cc: <[email protected]>
Signed-off-by: Christophe Leroy <[email protected]>
Signed-off-by: Daniel Thompson <[email protected]>

show more ...

kdb: use memmove instead of overlapping memcpy

gcc discovered that the memcpy() arguments in kdbnearsym() overlap, so
we should really use memmove(), which is defined to handle that correctly:

In f

kdb: use memmove instead of overlapping memcpy

gcc discovered that the memcpy() arguments in kdbnearsym() overlap, so
we should really use memmove(), which is defined to handle that correctly:

In function 'memcpy',
inlined from 'kdbnearsym' at /git/arm-soc/kernel/debug/kdb/kdb_support.c:132:4:
/git/arm-soc/include/linux/string.h:353:9: error: '__builtin_memcpy' accessing 792 bytes at offsets 0 and 8 overlaps 784 bytes at offset 8 [-Werror=restrict]
return __builtin_memcpy(p, q, size);

Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Jason Wessel <[email protected]>

show more ...

kdb: remove the second argument of k[un]map_atomic()

Signed-off-by: Cong Wang <[email protected]>

kdb: Make KDB use the new is_idle_task() API

Change from direct comparison of ->pid with zero to is_idle_task().

Signed-off-by: Paul E. McKenney <[email protected]>
Signed-off-by: Paul E. Mc

kdb: Make KDB use the new is_idle_task() API

Change from direct comparison of ->pid with zero to is_idle_task().

Signed-off-by: Paul E. McKenney <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>
Cc: Jason Wessel <[email protected]>
Reviewed-by: Josh Triplett <[email protected]>

show more ...

Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <[email protected]>

kdb: fix compile error without CONFIG_KALLSYMS

If CONFIG_KGDB_KDB is set and CONFIG_KALLSYMS is not set the kernel
will fail to build with the error:

kernel/built-in.o: In function `kallsyms_symbol

kdb: fix compile error without CONFIG_KALLSYMS

If CONFIG_KGDB_KDB is set and CONFIG_KALLSYMS is not set the kernel
will fail to build with the error:

kernel/built-in.o: In function `kallsyms_symbol_next':
kernel/debug/kdb/kdb_support.c:237: undefined reference to `kdb_walk_kallsyms'
kernel/built-in.o: In function `kallsyms_symbol_complete':
kernel/debug/kdb/kdb_support.c:193: undefined reference to `kdb_walk_kallsyms'

The kdb_walk_kallsyms needs a #ifdef proper header to match the C
implementation. This patch also fixes the compiler warnings in
kdb_support.c when compiling without CONFIG_KALLSYMS set. The
compiler warnings are a result of the kallsyms_lookup() macro not
initializing the two of the pass by reference variables.

Signed-off-by: Jason Wessel <[email protected]>
Reported-by: Michal Simek <[email protected]>

show more ...

kdb: core for kgdb back end (1 of 2)

This patch contains only the kdb core. Because the change set was
large, it was split. The next patch in the series includes the
instrumentation into the core

kdb: core for kgdb back end (1 of 2)

This patch contains only the kdb core. Because the change set was
large, it was split. The next patch in the series includes the
instrumentation into the core kernel which are mainly helper functions
for kdb.

This work is directly derived from kdb v4.4 found at:

ftp://oss.sgi.com/projects/kdb/download/v4.4/

The kdb internals have been re-organized to make them mostly platform
independent and to connect everything to the debug core which is used by
gdbstub (which has long been known as kgdb).

The original version of kdb was 58,000 lines worth of changes to
support x86. From that implementation only the kdb shell, and basic
commands for memory access, runcontrol, lsmod, and dmesg where carried
forward.

This is a generic implementation which aims to cover all the current
architectures using the kgdb core: ppc, arm, x86, mips, sparc, sh and
blackfin. More archictectures can be added by implementing the
architecture specific kgdb functions.

[[email protected]: Compile fix with hugepages enabled]
[[email protected]: Clean breakpoint code renaming kdba_ -> kdb_]
[[email protected]: fix new line after printing registers]
[[email protected]: Remove the concept of global vs. local breakpoints]
[[email protected]: Rework kdb_si_swapinfo to use more generic name]
[[email protected]: fix the information dump macros, remove 'arch' from the names]
[[email protected]: include fixup to include linux/slab.h]

CC: [email protected]
Signed-off-by: Jason Wessel <[email protected]>
Signed-off-by: Martin Hicks <[email protected]>

show more ...