[PATCH] Fix gcc-12 compiler warnings on lkcd_*.c
by HAGIO KAZUHITO(萩尾 一仁)
Without the patch, the following gcc-12 compiler warnings are emitted
for lkcd_*.c:
lkcd_v1.c: In function 'dump_lkcd_environment_v1':
lkcd_v1.c:252:20: warning: the comparison will always evaluate as 'true' for the address of 'dh_panic_string' will never be NULL [-Waddress]
252 | dh && dh->dh_panic_string &&
| ^~
In file included from lkcd_v1.c:21:
lkcd_vmdump_v1.h:108:30: note: 'dh_panic_string' declared here
108 | char dh_panic_string[DUMP_PANIC_LEN];
| ^~~~~~~~~~~~~~~
...
Reporeted-by: Lianbo Jiang <lijiang(a)redhat.com>
Signed-off-by: Kazuhito Hagio <k-hagio-ab(a)nec.com>
---
lkcd_v1.c | 3 +--
lkcd_v2_v3.c | 3 +--
lkcd_v5.c | 3 +--
lkcd_v7.c | 3 +--
lkcd_v8.c | 3 +--
5 files changed, 5 insertions(+), 10 deletions(-)
diff --git a/lkcd_v1.c b/lkcd_v1.c
index 5f891ae..31bdc04 100644
--- a/lkcd_v1.c
+++ b/lkcd_v1.c
@@ -249,8 +249,7 @@ dump_header_only:
lkcd_print(" dh_eip: %lx\n", dh->dh_eip);
lkcd_print(" dh_num_pages: %d\n", dh->dh_num_pages);
lkcd_print(" dh_panic_string: %s%s", dh->dh_panic_string,
- dh && dh->dh_panic_string &&
- strstr(dh->dh_panic_string, "\n") ? "" : "\n");
+ dh && strstr(dh->dh_panic_string, "\n") ? "" : "\n");
lkcd_print(" dh_time: %s\n",
strip_linefeeds(ctime(&(dh->dh_time.tv_sec))));
diff --git a/lkcd_v2_v3.c b/lkcd_v2_v3.c
index 8635a7b..edcb663 100644
--- a/lkcd_v2_v3.c
+++ b/lkcd_v2_v3.c
@@ -307,8 +307,7 @@ dump_header_only:
lkcd_print(" dh_num_pages: ");
lkcd_print(BITS32() ? "%ld\n" : "%d\n", dh->dh_num_pages);
lkcd_print(" dh_panic_string: %s%s", dh->dh_panic_string,
- dh && dh->dh_panic_string &&
- strstr(dh->dh_panic_string, "\n") ? "" : "\n");
+ dh && strstr(dh->dh_panic_string, "\n") ? "" : "\n");
lkcd_print(" dh_time: %s\n",
strip_linefeeds(ctime(&(dh->dh_time.tv_sec))));
diff --git a/lkcd_v5.c b/lkcd_v5.c
index cb7634d..e3bfa6f 100644
--- a/lkcd_v5.c
+++ b/lkcd_v5.c
@@ -270,8 +270,7 @@ dump_header_only:
lkcd_print(" dh_num_pages: ");
lkcd_print(BITS32() ? "%ld\n" : "%d\n", dh->dh_num_pages);
lkcd_print(" dh_panic_string: %s%s", dh->dh_panic_string,
- dh && dh->dh_panic_string &&
- strstr(dh->dh_panic_string, "\n") ? "" : "\n");
+ dh && strstr(dh->dh_panic_string, "\n") ? "" : "\n");
lkcd_print(" dh_time: %s\n",
strip_linefeeds(ctime(&(dh->dh_time.tv_sec))));
diff --git a/lkcd_v7.c b/lkcd_v7.c
index 608e148..97d9900 100644
--- a/lkcd_v7.c
+++ b/lkcd_v7.c
@@ -347,8 +347,7 @@ dump_header_only:
lkcd_print(" dh_num_pages: ");
lkcd_print(BITS32() ? "%ld\n" : "%d\n", dh->dh_num_pages);
lkcd_print(" dh_panic_string: %s%s", dh->dh_panic_string,
- dh && dh->dh_panic_string &&
- strstr(dh->dh_panic_string, "\n") ? "" : "\n");
+ dh && strstr(dh->dh_panic_string, "\n") ? "" : "\n");
lkcd_print(" dh_time: %s\n",
strip_linefeeds(ctime(&(dh->dh_time.tv_sec))));
diff --git a/lkcd_v8.c b/lkcd_v8.c
index 3b355e0..4167fa5 100644
--- a/lkcd_v8.c
+++ b/lkcd_v8.c
@@ -543,8 +543,7 @@ dump_header_only:
lkcd_print(" dh_num_pages: ");
lkcd_print(BITS32() ? "%ld\n" : "%d\n", dh->dh_num_pages);
lkcd_print(" dh_panic_string: %s%s", dh->dh_panic_string,
- dh && dh->dh_panic_string &&
- strstr(dh->dh_panic_string, "\n") ? "" : "\n");
+ dh && strstr(dh->dh_panic_string, "\n") ? "" : "\n");
tv.tv_sec = dh->dh_time.tv_sec;
lkcd_print(" dh_time: %s\n",
strip_linefeeds(ctime(&(tv.tv_sec))));
--
2.37.1
2 years
[PATCH v2] Fix kmem failing to print task context when address is vmalloced stack
by Tao Liu
When kernel enabled CONFIG_VMAP_STACK, stack can be allocated to
vmalloced area. Currently crash didn't handle the case, as a result,
kmem will not print the task context as expected. This patch fix the
bug by checking if the address is a vmalloced stack first.
Before:
crash> kmem ffffb7efce9bbe28
VMAP_AREA VM_STRUCT ADDRESS RANGE SIZE
ffff94eb9102c640 ffff94eb9102b140 ffffb7efce9b8000 - ffffb7efce9bd000 20480
PAGE PHYSICAL MAPPING INDEX CNT FLAGS
ffffdd28220dc000 1883700000 0 0 1 50000000000000
After:
crash> kmem ffffb7efce9bbe28
PID: 847
COMMAND: "khungtaskd"
TASK: ffff94f8038f4000 [THREAD_INFO: ffff94f8038f4000]
CPU: 72
STATE: TASK_RUNNING (PANIC)
VMAP_AREA VM_STRUCT ADDRESS RANGE SIZE
ffff94eb9102c640 ffff94eb9102b140 ffffb7efce9b8000 - ffffb7efce9bd000 20480
PAGE PHYSICAL MAPPING INDEX CNT FLAGS
ffffdd28220dc000 1883700000 0 0 1 50000000000000
Signed-off-by: Tao Liu <ltao(a)redhat.com>
---
v1 -> v2: 1) Remove goto to print task context and vmlist.
2) Update commit log to show the change.
---
memory.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/memory.c b/memory.c
index 7339f0c..9ab5781 100644
--- a/memory.c
+++ b/memory.c
@@ -13477,6 +13477,10 @@ kmem_search(struct meminfo *mi)
* Check for a valid mapped address.
*/
if ((mi->memtype == KVADDR) && IS_VMALLOC_ADDR(mi->spec_addr)) {
+ if ((task = stkptr_to_task(vaddr)) && (tc = task_to_context(task))) {
+ show_context(tc);
+ fprintf(fp, "\n");
+ }
if (kvtop(NULL, mi->spec_addr, &paddr, 0)) {
mi->flags = orig_flags | VMLIST_VERIFY;
dump_vmlist(mi);
--
2.33.1
2 years
Re: [Crash-utility] [PATCH v2] Add ending identifier for union when parsing task structure
by lijiang
On Mon, Aug 29, 2022 at 3:21 PM <crash-utility-request(a)redhat.com> wrote:
> Date: Mon, 29 Aug 2022 07:15:15 +0000
> From: HAGIO KAZUHITO(?????) <k-hagio-ab(a)nec.com>
> To: "Discussion list for crash utility usage, maintenance and
> development" <crash-utility(a)redhat.com>, Tao Liu <ltao(a)redhat.com>
> Subject: Re: [Crash-utility] [PATCH v2] Add ending identifier for
> union when parsing task structure
> Message-ID: <b5f22630-9649-20a2-6233-f229f76353dc(a)nec.com>
> Content-Type: text/plain; charset="utf-8"
>
> On 2022/08/25 15:39, Tao Liu wrote:
> > Previously, the start and end identifier for union is " {\n"
> > and " }, \n". However the end identifier is not always as
> > expected. " },\n" can also be the end identifier. As a result,
> > variable "randomized" is in incorrect state after union, and
> > fails to identify the later struct members. For example, we can
> > reproduce the issue as follows:
> >
> > crash> task
> > PID: 847 TASK: ffff94f8038f4000 CPU: 72 COMMAND:
> "khungtaskd"
> > struct task_struct {
> > thread_info = {
> > flags = 2148024320,
> > status = 0,
> > preempt_lazy_count = 0
> > },
> > {
> > <the union>
> > },
> > ...
> > wake_entry = {
> > next = 0x0
> > },
> > ...
> >
> > Before patch:
> >
> > crash> task -R wake_entry
> > PID: 847 TASK: ffff94f8038f4000 CPU: 72 COMMAND:
> "khungtaskd"
> >
> > After patch:
> >
> > crash> task -R wake_entry
> > PID: 847 TASK: ffff94f8038f4000 CPU: 72 COMMAND:
> "khungtaskd"
> > wake_entry = {
> > next = 0x0
> > },
> >
> > Signed-off-by: Tao Liu <ltao(a)redhat.com>
> > ---
> >
> > v1 -> v2: Rewrite the commit log.
>
> Thanks for the update.
>
> I will add "with gdb-10.2" to the commit log when applying.
>
>
This is indeed a specific gdb-10.2 issue. They have different output styles
between gdb-7.6 and gdb-10.2.
> Acked-by: Kazuhito Hagio <k-hagio-ab(a)nec.com>
>
> Thanks,
> Kazu
>
>
> >
> > ---
> > task.c | 3 ++-
> > 1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/task.c b/task.c
> > index 071c787..db2abc8 100644
> > --- a/task.c
> > +++ b/task.c
> > @@ -3436,7 +3436,8 @@ parse_task_thread(int argcnt, char *arglist[],
> struct task_context *tc) {
> > while (fgets(buf, BUFSIZE, pc->tmpfile)) {
> > if (STREQ(buf, " {\n"))
> > randomized = TRUE;
> > - else if (randomized && STREQ(buf, " }, \n"))
> > + else if (randomized &&
> > + (STREQ(buf, " }, \n") || STREQ(buf, " },\n")))
>
This change looks good, and the test is ok. So for the v2: Ack.
Thanks.
Lianbo
> randomized = FALSE;
> >
> > if (strlen(lookfor2)) {
>
2 years
[PATCH v3 1/2] Let gdb get kernel module symbols info from crash
by Tao Liu
Gdb will try to resolve an address to its corresponding symbol name such as
when printing a structure. It works fine for kernel symbols, because gdb can
find them through vmlinux. However as for kernel modules symbols, crash
resolves them by dig into "struct module", which gdb don't know. As a
results, gdb fails to translate an kernel modules address to it's symbolic
name. For example we can reproduce the issue as follows.
crash> timer
....
4331308176 336 ffff94ea24240860 ffffffffc03762c0 <estimation_timer>
....
crash> sym 0xffffffffc03762c0
ffffffffc03762c0 (t) estimation_timer [ip_vs]
Before patch:
crash> timer_list ffff94ea24240860
struct timer_list {
....
function = 0xffffffffc03762c0,
....
}
After patch:
crash> timer_list ffff94ea24240860
struct timer_list {
....
function = 0xffffffffc03762c0 <estimation_timer>,
....
}
In this patch, we add an interface for gdb, when gdb trying to build kernel
module's address symbolic, the info can be get from crash.
Signed-off-by: Tao Liu <ltao(a)redhat.com>
---
v1 -> v2: Append the modification hunk at the end of gdb-10.2.patch
v2 -> v3: Add printcmd.c to "tar xvzmf"
---
defs.h | 2 ++
gdb-10.2.patch | 35 +++++++++++++++++++++++++++++++++++
gdb_interface.c | 12 ++++++++++++
3 files changed, 49 insertions(+)
diff --git a/defs.h b/defs.h
index 9d6d891..afdcf6c 100644
--- a/defs.h
+++ b/defs.h
@@ -4874,6 +4874,7 @@ extern "C" int patch_kernel_symbol(struct gnu_request *);
struct syment *symbol_search(char *);
int gdb_line_number_callback(ulong, ulong, ulong);
int gdb_print_callback(ulong);
+char *gdb_lookup_module_symbol(ulong, ulong *);
extern "C" int same_file(char *, char *);
#endif
@@ -7284,6 +7285,7 @@ int gdb_pass_through(char *, FILE *, ulong);
int gdb_readmem_callback(ulong, void *, int, int);
int gdb_line_number_callback(ulong, ulong, ulong);
int gdb_print_callback(ulong);
+char *gdb_lookup_module_symbol(ulong, ulong *);
void gdb_error_hook(void);
void restore_gdb_sanity(void);
int is_gdb_command(int, ulong);
diff --git a/gdb-10.2.patch b/gdb-10.2.patch
index f0034ed..642cd6a 100644
--- a/gdb-10.2.patch
+++ b/gdb-10.2.patch
@@ -9,6 +9,7 @@
# to all subsequent patch applications.
tar xvzmf gdb-10.2.tar.gz \
+ gdb-10.2/gdb/printcmd.c \
gdb-10.2/gdb/symfile.c \
gdb-10.2/gdb/Makefile.in
@@ -1661,3 +1662,37 @@ exit 0
+ return name_copy ? std::string (name_copy) : std::string ();
}
#endif
+
+--- gdb-10.2/gdb/printcmd.c.orig
++++ gdb-10.2/gdb/printcmd.c
+@@ -576,6 +576,10 @@ print_address_symbolic (struct gdbarch *gdbarch, CORE_ADDR addr,
+
+ /* See valprint.h. */
+
++#ifdef CRASH_MERGE
++extern "C" char *gdb_lookup_module_symbol(unsigned long, unsigned long *);
++#endif
++
+ int
+ build_address_symbolic (struct gdbarch *gdbarch,
+ CORE_ADDR addr, /* IN */
+@@ -682,7 +686,19 @@ build_address_symbolic (struct gdbarch *gdbarch,
+ }
+ }
+ if (symbol == NULL && msymbol.minsym == NULL)
++#ifdef CRASH_MERGE
++ {
++ char *name_ptr = gdb_lookup_module_symbol(addr, (unsigned long *)offset);
++ if (name_ptr) {
++ *name = name_ptr;
++ return 0;
++ } else {
++ return 1;
++ }
++ }
++#else
+ return 1;
++#endif
+
+ /* If the nearest symbol is too far away, don't print anything symbolic. */
+
diff --git a/gdb_interface.c b/gdb_interface.c
index 3a7fcc9..b14319c 100644
--- a/gdb_interface.c
+++ b/gdb_interface.c
@@ -935,6 +935,18 @@ gdb_print_callback(ulong addr)
return IS_KVADDR(addr);
}
+char *
+gdb_lookup_module_symbol(ulong addr, ulong *offset)
+{
+ struct syment *sp;
+
+ if ((sp = value_search_module(addr, offset))) {
+ return sp->name;
+ } else {
+ return NULL;
+ }
+}
+
/*
* Used by gdb_interface() to catch gdb-related errors, if desired.
*/
--
2.33.1
2 years
Re: [Crash-utility] [PATCH v3 1/2] Let gdb get kernel module symbols info from crash
by lijiang
Hi, Tao
Thank you for the update.
On Wed, Aug 31, 2022 at 11:58 AM <crash-utility-request(a)redhat.com> wrote:
> Date: Wed, 31 Aug 2022 11:54:13 +0800
> From: Tao Liu <ltao(a)redhat.com>
> To: crash-utility(a)redhat.com
> Subject: [Crash-utility] [PATCH v3 1/2] Let gdb get kernel module
> symbols info from crash
> Message-ID: <20220831035413.10831-1-ltao(a)redhat.com>
> Content-Type: text/plain; charset="US-ASCII"; x-default=true
>
> Gdb will try to resolve an address to its corresponding symbol name such as
> when printing a structure. It works fine for kernel symbols, because gdb
> can
> find them through vmlinux. However as for kernel modules symbols, crash
> resolves them by dig into "struct module", which gdb don't know. As a
> results, gdb fails to translate an kernel modules address to it's symbolic
> name. For example we can reproduce the issue as follows.
>
> crash> timer
> ....
> 4331308176 336 ffff94ea24240860 ffffffffc03762c0
> <estimation_timer>
> ....
> crash> sym 0xffffffffc03762c0
> ffffffffc03762c0 (t) estimation_timer [ip_vs]
>
> Before patch:
> crash> timer_list ffff94ea24240860
> struct timer_list {
> ....
> function = 0xffffffffc03762c0,
> ....
> }
>
> After patch:
> crash> timer_list ffff94ea24240860
> struct timer_list {
> ....
> function = 0xffffffffc03762c0 <estimation_timer>,
> ....
> }
>
> In this patch, we add an interface for gdb, when gdb trying to build kernel
> module's address symbolic, the info can be get from crash.
>
> Signed-off-by: Tao Liu <ltao(a)redhat.com>
> ---
> v1 -> v2: Append the modification hunk at the end of gdb-10.2.patch
> v2 -> v3: Add printcmd.c to "tar xvzmf"
>
For the v3 patchset: Ack.
Thanks.
Lianbo
---
> defs.h | 2 ++
> gdb-10.2.patch | 35 +++++++++++++++++++++++++++++++++++
> gdb_interface.c | 12 ++++++++++++
> 3 files changed, 49 insertions(+)
>
> diff --git a/defs.h b/defs.h
> index 9d6d891..afdcf6c 100644
> --- a/defs.h
> +++ b/defs.h
> @@ -4874,6 +4874,7 @@ extern "C" int patch_kernel_symbol(struct
> gnu_request *);
> struct syment *symbol_search(char *);
> int gdb_line_number_callback(ulong, ulong, ulong);
> int gdb_print_callback(ulong);
> +char *gdb_lookup_module_symbol(ulong, ulong *);
> extern "C" int same_file(char *, char *);
> #endif
>
> @@ -7284,6 +7285,7 @@ int gdb_pass_through(char *, FILE *, ulong);
> int gdb_readmem_callback(ulong, void *, int, int);
> int gdb_line_number_callback(ulong, ulong, ulong);
> int gdb_print_callback(ulong);
> +char *gdb_lookup_module_symbol(ulong, ulong *);
> void gdb_error_hook(void);
> void restore_gdb_sanity(void);
> int is_gdb_command(int, ulong);
> diff --git a/gdb-10.2.patch b/gdb-10.2.patch
> index f0034ed..642cd6a 100644
> --- a/gdb-10.2.patch
> +++ b/gdb-10.2.patch
> @@ -9,6 +9,7 @@
> # to all subsequent patch applications.
>
> tar xvzmf gdb-10.2.tar.gz \
> + gdb-10.2/gdb/printcmd.c \
> gdb-10.2/gdb/symfile.c \
> gdb-10.2/gdb/Makefile.in
>
> @@ -1661,3 +1662,37 @@ exit 0
> + return name_copy ? std::string (name_copy) : std::string ();
> }
> #endif
> +
> +--- gdb-10.2/gdb/printcmd.c.orig
> ++++ gdb-10.2/gdb/printcmd.c
> +@@ -576,6 +576,10 @@ print_address_symbolic (struct gdbarch *gdbarch,
> CORE_ADDR addr,
> +
> + /* See valprint.h. */
> +
> ++#ifdef CRASH_MERGE
> ++extern "C" char *gdb_lookup_module_symbol(unsigned long, unsigned long
> *);
> ++#endif
> ++
> + int
> + build_address_symbolic (struct gdbarch *gdbarch,
> + CORE_ADDR addr, /* IN */
> +@@ -682,7 +686,19 @@ build_address_symbolic (struct gdbarch *gdbarch,
> + }
> + }
> + if (symbol == NULL && msymbol.minsym == NULL)
> ++#ifdef CRASH_MERGE
> ++ {
> ++ char *name_ptr = gdb_lookup_module_symbol(addr, (unsigned long
> *)offset);
> ++ if (name_ptr) {
> ++ *name = name_ptr;
> ++ return 0;
> ++ } else {
> ++ return 1;
> ++ }
> ++ }
> ++#else
> + return 1;
> ++#endif
> +
> + /* If the nearest symbol is too far away, don't print anything
> symbolic. */
> +
> diff --git a/gdb_interface.c b/gdb_interface.c
> index 3a7fcc9..b14319c 100644
> --- a/gdb_interface.c
> +++ b/gdb_interface.c
> @@ -935,6 +935,18 @@ gdb_print_callback(ulong addr)
> return IS_KVADDR(addr);
> }
>
> +char *
> +gdb_lookup_module_symbol(ulong addr, ulong *offset)
> +{
> + struct syment *sp;
> +
> + if ((sp = value_search_module(addr, offset))) {
> + return sp->name;
> + } else {
> + return NULL;
> + }
> +}
> +
> /*
> * Used by gdb_interface() to catch gdb-related errors, if desired.
> */
> --
> 2.33.1
>
>
>
> ------------------------------
>
> Subject: Digest Footer
>
> --
> Crash-utility mailing list
> Crash-utility(a)redhat.com
> https://listman.redhat.com/mailman/listinfo/crash-utility
>
>
> ------------------------------
>
> End of Crash-utility Digest, Vol 203, Issue 48
> **********************************************
>
>
2 years
[PATCH v2 1/2] Let gdb get kernel module symbols info from crash
by Tao Liu
Gdb will try to resolve an address to its corresponding symbol name such as
when printing a structure. It works fine for kernel symbols, because gdb can
find them through vmlinux. However as for kernel modules symbols, crash
resolves them by dig into "struct module", which gdb don't know. As a
results, gdb fails to translate an kernel modules address to it's symbolic
name. For example we can reproduce the issue as follows.
crash> timer
....
4331308176 336 ffff94ea24240860 ffffffffc03762c0 <estimation_timer>
....
crash> sym 0xffffffffc03762c0
ffffffffc03762c0 (t) estimation_timer [ip_vs]
Before patch:
crash> timer_list ffff94ea24240860
struct timer_list {
....
function = 0xffffffffc03762c0,
....
}
After patch:
crash> timer_list ffff94ea24240860
struct timer_list {
....
function = 0xffffffffc03762c0 <estimation_timer>,
....
}
In this patch, we add an interface for gdb, when gdb trying to build kernel
module's address symbolic, the info can be get from crash.
Signed-off-by: Tao Liu <ltao(a)redhat.com>
---
v1 -> v2: Append the modification hunk at the end of gdb-10.2.patch
---
defs.h | 2 ++
gdb-10.2.patch | 34 ++++++++++++++++++++++++++++++++++
gdb_interface.c | 12 ++++++++++++
3 files changed, 48 insertions(+)
diff --git a/defs.h b/defs.h
index 9d6d891..afdcf6c 100644
--- a/defs.h
+++ b/defs.h
@@ -4874,6 +4874,7 @@ extern "C" int patch_kernel_symbol(struct gnu_request *);
struct syment *symbol_search(char *);
int gdb_line_number_callback(ulong, ulong, ulong);
int gdb_print_callback(ulong);
+char *gdb_lookup_module_symbol(ulong, ulong *);
extern "C" int same_file(char *, char *);
#endif
@@ -7284,6 +7285,7 @@ int gdb_pass_through(char *, FILE *, ulong);
int gdb_readmem_callback(ulong, void *, int, int);
int gdb_line_number_callback(ulong, ulong, ulong);
int gdb_print_callback(ulong);
+char *gdb_lookup_module_symbol(ulong, ulong *);
void gdb_error_hook(void);
void restore_gdb_sanity(void);
int is_gdb_command(int, ulong);
diff --git a/gdb-10.2.patch b/gdb-10.2.patch
index f0034ed..4fe16b0 100644
--- a/gdb-10.2.patch
+++ b/gdb-10.2.patch
@@ -1661,3 +1661,37 @@ exit 0
+ return name_copy ? std::string (name_copy) : std::string ();
}
#endif
+
+--- gdb-10.2/gdb/printcmd.c.orig
++++ gdb-10.2/gdb/printcmd.c
+@@ -576,6 +576,10 @@ print_address_symbolic (struct gdbarch *gdbarch, CORE_ADDR addr,
+
+ /* See valprint.h. */
+
++#ifdef CRASH_MERGE
++extern "C" char *gdb_lookup_module_symbol(unsigned long, unsigned long *);
++#endif
++
+ int
+ build_address_symbolic (struct gdbarch *gdbarch,
+ CORE_ADDR addr, /* IN */
+@@ -682,7 +686,19 @@ build_address_symbolic (struct gdbarch *gdbarch,
+ }
+ }
+ if (symbol == NULL && msymbol.minsym == NULL)
++#ifdef CRASH_MERGE
++ {
++ char *name_ptr = gdb_lookup_module_symbol(addr, (unsigned long *)offset);
++ if (name_ptr) {
++ *name = name_ptr;
++ return 0;
++ } else {
++ return 1;
++ }
++ }
++#else
+ return 1;
++#endif
+
+ /* If the nearest symbol is too far away, don't print anything symbolic. */
+
diff --git a/gdb_interface.c b/gdb_interface.c
index 3a7fcc9..b14319c 100644
--- a/gdb_interface.c
+++ b/gdb_interface.c
@@ -935,6 +935,18 @@ gdb_print_callback(ulong addr)
return IS_KVADDR(addr);
}
+char *
+gdb_lookup_module_symbol(ulong addr, ulong *offset)
+{
+ struct syment *sp;
+
+ if ((sp = value_search_module(addr, offset))) {
+ return sp->name;
+ } else {
+ return NULL;
+ }
+}
+
/*
* Used by gdb_interface() to catch gdb-related errors, if desired.
*/
--
2.33.1
2 years
[PATCH] filesys.c: add debian vmlinux loc to default search dirs
by brookxu
From: "Chunguang.Xu" <chunguang.xu(a)shopee.com>
Now crash cannnot found debian/ubuntu kernel vmlinux, we need
to explicitly specify the path to vmlinux. Try to add the debian
vmlinux location to default search dirs.
Signed-off-by: Chunguang Xu <chunguang.xu(a)shopee.com>
---
filesys.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/filesys.c b/filesys.c
index a863f04..c2ea78d 100644
--- a/filesys.c
+++ b/filesys.c
@@ -319,7 +319,7 @@ match_proc_version(void)
#define CREATE 1
#define DESTROY 0
-#define DEFAULT_SEARCHDIRS 5
+#define DEFAULT_SEARCHDIRS 6
#define EXTRA_SEARCHDIRS 5
static char **
@@ -336,6 +336,7 @@ build_searchdirs(int create, int *preferred)
"/boot/",
"/boot/efi/redhat",
"/boot/efi/EFI/redhat",
+ "/usr/lib/debug/boot/",
"/",
NULL
};
--
2.25.1
2 years
Re: [Crash-utility] [PATCH 2/2] x86_64: Correct the identifier when locating the call instruction
by lijiang
On Wed, Aug 24, 2022 at 3:54 PM <crash-utility-request(a)redhat.com> wrote:
> Date: Wed, 24 Aug 2022 12:10:35 +0800
> From: Tao Liu <ltao(a)redhat.com>
> To: crash-utility(a)redhat.com
> Subject: [Crash-utility] [PATCH 2/2] x86_64: Correct the identifier
> when locating the call instruction
> Message-ID: <20220824041033.40559-2-ltao(a)redhat.com>
> Content-Type: text/plain; charset="US-ASCII"; x-default=true
>
> The previous implementation to locate the call instruction is
> to strstr "call", then check whether the previous char is ' '
> or '\t'. The implementation is problematic. For example it
> cannot resolve the following disassembly string:
>
> "0xffffffffc06e6399 <nfs_callback_up+118>:\tcall 0xffffffff9ac8792f
> <printk>"
>
> strstr will locate the "_call" and char check fails,
> as a result, extract_hex fail to get the calling address.
>
>
This looks like a potential corner bug. Did you see if it can be reproduced
without the [PATCH 1/2]?
Thanks.
Lianbo
This patch fix the issue by strstr "\tcall" and " call", to
> locate the correct call instruction.
>
> Signed-off-by: Tao Liu <ltao(a)redhat.com>
> ---
> x86_64.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/x86_64.c b/x86_64.c
> index dfada48..74bd1bb 100644
> --- a/x86_64.c
> +++ b/x86_64.c
> @@ -4432,8 +4432,7 @@ x86_64_function_called_by(ulong rip)
> if (gdb_pass_through(buf, pc->tmpfile2, GNU_RETURN_ON_ERROR)) {
> rewind(pc->tmpfile2);
> while (fgets(buf, BUFSIZE, pc->tmpfile2)) {
> - if ((p1 = strstr(buf, "call")) &&
> - whitespace(*(p1-1))) {
> + if ((p1 = strstr(buf, " call")) || (p1 =
> strstr(buf, "\tcall"))) {
if (extract_hex(p1, &value, NULLCHAR,
> TRUE))
> break;
> }
> --
> 2.33.1
>
2 years
Re: [Crash-utility] [PATCH 1/2] Let gdb get kernel module symbols info from crash
by lijiang
Hi, Tao
Thank you for the patch.
On Wed, Aug 24, 2022 at 12:12 PM <crash-utility-request(a)redhat.com> wrote:
>
> Date: Wed, 24 Aug 2022 12:10:33 +0800
> From: Tao Liu <ltao(a)redhat.com>
> To: crash-utility(a)redhat.com
> Subject: [Crash-utility] [PATCH 1/2] Let gdb get kernel module symbols
> info from crash
> Message-ID: <20220824041033.40559-1-ltao(a)redhat.com>
> Content-Type: text/plain; charset="US-ASCII"; x-default=true
>
> Gdb will try to resolve an address to its corresponding symbol name such as
> when printing a structure. It works fine for kernel symbols, because gdb
> can
> find them through vmlinux. However as for kernel modules symbols, crash
> resolves them by dig into "struct module", which gdb don't know. As a
> results, gdb fails to translate an kernel modules address to it's symbolic
> name. For example we can reproduce the issue as follows.
>
> crash> timer
> ....
> 4331308176 336 ffff94ea24240860 ffffffffc03762c0
> <estimation_timer>
> ....
> crash> sym 0xffffffffc03762c0
> ffffffffc03762c0 (t) estimation_timer [ip_vs]
>
> Before patch:
> crash> timer_list ffff94ea24240860
> struct timer_list {
> ....
> function = 0xffffffffc03762c0,
> ....
> }
>
> After patch:
> crash> timer_list ffff94ea24240860
> struct timer_list {
> ....
> function = 0xffffffffc03762c0 <estimation_timer>,
> ....
> }
>
> In this patch, we add an interface for gdb, when gdb trying to build kernel
> module's address symbolic, the info can be get from crash.
>
> Signed-off-by: Tao Liu <ltao(a)redhat.com>
> ---
> defs.h | 2 ++
> gdb-10.2.patch | 35 +++++++++++++++++++++++++++++++++--
> gdb_interface.c | 12 ++++++++++++
> 3 files changed, 47 insertions(+), 2 deletions(-)
>
> diff --git a/defs.h b/defs.h
> index 9d6d891..afdcf6c 100644
> --- a/defs.h
> +++ b/defs.h
> @@ -4874,6 +4874,7 @@ extern "C" int patch_kernel_symbol(struct
> gnu_request *);
> struct syment *symbol_search(char *);
> int gdb_line_number_callback(ulong, ulong, ulong);
> int gdb_print_callback(ulong);
> +char *gdb_lookup_module_symbol(ulong, ulong *);
> extern "C" int same_file(char *, char *);
> #endif
>
> @@ -7284,6 +7285,7 @@ int gdb_pass_through(char *, FILE *, ulong);
> int gdb_readmem_callback(ulong, void *, int, int);
> int gdb_line_number_callback(ulong, ulong, ulong);
> int gdb_print_callback(ulong);
> +char *gdb_lookup_module_symbol(ulong, ulong *);
> void gdb_error_hook(void);
> void restore_gdb_sanity(void);
> int is_gdb_command(int, ulong);
> diff --git a/gdb-10.2.patch b/gdb-10.2.patch
> index f0034ed..d08e9ab 100644
> --- a/gdb-10.2.patch
> +++ b/gdb-10.2.patch
> @@ -399,7 +399,38 @@ exit 0
> if (build_address_symbolic (gdbarch, addr, do_demangle, false, &name,
> &offset, &filename, &line, &unmapped))
> return 0;
> -@@ -1221,6 +1230,43 @@ print_command_1 (const char *args, int voidprint)
> +@@ -567,6 +576,10 @@ print_address_symbolic (struct gdbarch *gdbarch,
> CORE_ADDR addr,
> +
> + /* See valprint.h. */
> +
> ++#ifdef CRASH_MERGE
> ++extern "C" char *gdb_lookup_module_symbol(unsigned long, unsigned long
> *);
> ++#endif
> ++
> + int
> + build_address_symbolic (struct gdbarch *gdbarch,
> + CORE_ADDR addr, /* IN */
> +@@ -673,7 +686,19 @@ build_address_symbolic (struct gdbarch *gdbarch,
> + }
> + }
> + if (symbol == NULL && msymbol.minsym == NULL)
> ++#ifdef CRASH_MERGE
> ++ {
> ++ char *name_ptr = gdb_lookup_module_symbol(addr, (unsigned long
> *)offset);
> ++ if (name_ptr) {
> ++ *name = name_ptr;
> ++ return 0;
> ++ } else {
> ++ return 1;
> ++ }
> ++ }
> ++#else
> + return 1;
> ++#endif
> +
> + /* If the nearest symbol is too far away, don't print anything
> symbolic. */
> +
> +@@ -1221,6 +1246,43 @@ print_command_1 (const char *args, int voidprint)
> print_value (val, print_opts);
> }
>
>
Usually, the gdb patch needs to be put at the end of gdb-10.2.patch, which
can help to
apply your patch correctly. Could you please refer to the following commit?
4c85e982d25a ("gdb: fix for assigning NULL to std::string")
In some commands, crash will trigger symbols loading via the
value_search(), and also decide if the module symbols need to be loaded
there, but for this case, there seems to be no better solution.
Thanks.
Lianbo
@@ -443,7 +474,7 @@ exit 0
> /* See valprint.h. */
>
> void
> -@@ -2855,6 +2901,12 @@ but no count or size letter (see \"x\" command)."),
> +@@ -2855,6 +2917,12 @@ but no count or size letter (see \"x\" command)."),
> c = add_com ("print", class_vars, print_command, print_help.c_str ());
> set_cmd_completer_handle_brkchars (c, print_command_completer);
> add_com_alias ("p", "print", class_vars, 1);
> diff --git a/gdb_interface.c b/gdb_interface.c
> index 3a7fcc9..b14319c 100644
> --- a/gdb_interface.c
> +++ b/gdb_interface.c
> @@ -935,6 +935,18 @@ gdb_print_callback(ulong addr)
> return IS_KVADDR(addr);
> }
>
> +char *
> +gdb_lookup_module_symbol(ulong addr, ulong *offset)
> +{
> + struct syment *sp;
> +
> + if ((sp = value_search_module(addr, offset))) {
> + return sp->name;
> + } else {
> + return NULL;
> + }
> +}
> +
> /*
> * Used by gdb_interface() to catch gdb-related errors, if desired.
> */
> --
> 2.33.1
>
>
2 years
[PATCH v2] Add ending identifier for union when parsing task structure
by Tao Liu
Previously, the start and end identifier for union is " {\n"
and " }, \n". However the end identifier is not always as
expected. " },\n" can also be the end identifier. As a result,
variable "randomized" is in incorrect state after union, and
fails to identify the later struct members. For example, we can
reproduce the issue as follows:
crash> task
PID: 847 TASK: ffff94f8038f4000 CPU: 72 COMMAND: "khungtaskd"
struct task_struct {
thread_info = {
flags = 2148024320,
status = 0,
preempt_lazy_count = 0
},
{
<the union>
},
...
wake_entry = {
next = 0x0
},
...
Before patch:
crash> task -R wake_entry
PID: 847 TASK: ffff94f8038f4000 CPU: 72 COMMAND: "khungtaskd"
After patch:
crash> task -R wake_entry
PID: 847 TASK: ffff94f8038f4000 CPU: 72 COMMAND: "khungtaskd"
wake_entry = {
next = 0x0
},
Signed-off-by: Tao Liu <ltao(a)redhat.com>
---
v1 -> v2: Rewrite the commit log.
---
task.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/task.c b/task.c
index 071c787..db2abc8 100644
--- a/task.c
+++ b/task.c
@@ -3436,7 +3436,8 @@ parse_task_thread(int argcnt, char *arglist[], struct task_context *tc) {
while (fgets(buf, BUFSIZE, pc->tmpfile)) {
if (STREQ(buf, " {\n"))
randomized = TRUE;
- else if (randomized && STREQ(buf, " }, \n"))
+ else if (randomized &&
+ (STREQ(buf, " }, \n") || STREQ(buf, " },\n")))
randomized = FALSE;
if (strlen(lookfor2)) {
--
2.33.1
2 years
