4:49 a.m.
This patchset deals with a few kmem failing to output task context
issues.
For CONFIG_VMAP_STACK enabled:
patch 1 deals with "kmem <virtual_address>" when vaddr is
vmalloced stack.
patch 3 deals with "kmem <physical_address>" when vaddr is
vmalloced stack and paddr is converted from the vaddr.
patch 2 is needed by patch 3, it will convert the correct
physical address to virtual address.
For CONFIG_VMAP_STACK not enabled:
patch 4 deals with "kmem <physical_address>", letting it have
the same output as "kmem <virtual_address>", when paddr
is converted from vaddr.
v2 -> v3: Add the kmem <physical_address> case.
v3 -> v4: Add patch 4 case.
v1: https://listman.redhat.com/archives/crash-utility/2022-August/010061.html
v2: https://listman.redhat.com/archives/crash-utility/2022-August/010074.html
v3: https://listman.redhat.com/archives/crash-utility/2022-September/010114.html
Tao Liu (4):
Fix kmem failing to print task context when address is vmalloced stack
Fix page offset issue when converting physical to virtual address
Let kmem print task context when physical address is vmalloced stack
Let kmem print task context with physical address
memory.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
--
2.33.1
4:49 a.m.
New subject: [PATCH v4 1/4] Fix kmem failing to print task context when address is vmalloced stack
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>
---
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
4:49 a.m.
New subject: [PATCH v4 2/4] Fix page offset issue when converting physical to virtual address
When trying to convert a physical address to its virtual
address in dump_vmap_area() and dump_vmlist(), the vi->retval
is added by 2 values: the page aligned address "pcheck"
and page offset address "PAGEOFFSET(paddr)".
However "paddr" is given by "pcheck", is also page aligned,
so "PAGEOFFSET(paddr)" is always 0.
In this patch, we will use PAGEOFFSET(vi->spec_addr) to give the
page offset, vi->spec_addr is the physical address we'd like
to convert, which contains the correct page offset.
Signed-off-by: Tao Liu <ltao(a)redhat.com>
---
memory.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/memory.c b/memory.c
index 9ab5781..1b6f9ba 100644
--- a/memory.c
+++ b/memory.c
@@ -8861,7 +8861,7 @@ dump_vmlist(struct meminfo *vi)
(vi->spec_addr < (paddr+PAGESIZE()))) {
if (vi->flags & GET_PHYS_TO_VMALLOC) {
vi->retval = pcheck +
- PAGEOFFSET(paddr);
+ PAGEOFFSET(vi->spec_addr);
return;
} else
fprintf(fp,
@@ -9010,7 +9010,7 @@ dump_vmap_area(struct meminfo *vi)
(vi->spec_addr < (paddr+PAGESIZE()))) {
if (vi->flags & GET_PHYS_TO_VMALLOC) {
vi->retval = pcheck +
- PAGEOFFSET(paddr);
+ PAGEOFFSET(vi->spec_addr);
FREEBUF(ld->list_ptr);
return;
} else
--
2.33.1
4:49 a.m.
New subject: [PATCH v4 3/4] Let kmem print task context when physical address is vmalloced stack
Patch [1] enables kmem to print task context if the given virtual
address is a vmalloced stack.
This patch handles the same issue except the given address is
physical address.
Before:
crash> kmem 1883700e28
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 1883700e28
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
[1]: https://listman.redhat.com/archives/crash-utility/2022-September/010115.html
Signed-off-by: Tao Liu <ltao(a)redhat.com>
---
memory.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/memory.c b/memory.c
index 1b6f9ba..eac8262 100644
--- a/memory.c
+++ b/memory.c
@@ -13506,6 +13506,10 @@ kmem_search(struct meminfo *mi)
mi->flags &= ~GET_PHYS_TO_VMALLOC;
if (mi->retval) {
+ if ((task = stkptr_to_task(mi->retval)) && (tc = task_to_context(task))) {
+ show_context(tc);
+ fprintf(fp, "\n");
+ }
if ((sp = value_search(mi->retval, &offset))) {
show_symbol(sp, offset,
SHOW_LINENUM | SHOW_RADIX());
--
2.33.1
4:49 a.m.
New subject: [PATCH v4 4/4] Let kmem print task context with physical address
With patch [1], kmem <phyaddr> will print task context when
CONFIG_VMAP_STACK enabled. However when CONFIG_VMAP_STACK disabled,
kmem <phyaddr> will never print task context, so the behaviour is
inconsistent.
This patch addresses the issue, to let kmem <phyaddr> can output
task context when CONFIG_VMAP_STACK disabled.
Before:
crash> kmem 16663edfda0
PAGE PHYSICAL MAPPING INDEX CNT FLAGS
ffffee33998fb7c0 16663edf000 0 0 0 6fffff00000000
After:
crash> kmem 16663edfda0
PID: 19007
COMMAND: "bash"
TASK: ffff8bb405d320e0 [THREAD_INFO: ffff8bb463edc000]
CPU: 59
STATE: TASK_RUNNING (SYSRQ)
PAGE PHYSICAL MAPPING INDEX CNT FLAGS
ffffee33998fb7c0 16663edf000 0 0 0 6fffff00000000
[1]: https://listman.redhat.com/archives/crash-utility/2022-September/010117.html
Signed-off-by: Tao Liu <ltao(a)redhat.com>
---
memory.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/memory.c b/memory.c
index eac8262..d0daa58 100644
--- a/memory.c
+++ b/memory.c
@@ -13566,11 +13566,13 @@ kmem_search(struct meminfo *mi)
/*
* Check whether it's a current task or stack address.
*/
- if ((mi->memtype == KVADDR) && (task = vaddr_in_task_struct(vaddr))
&&
+ if (((mi->memtype == KVADDR) || (mi->memtype == PHYSADDR)) &&
+ (task = vaddr_in_task_struct(vaddr)) &&
(tc = task_to_context(task))) {
show_context(tc);
fprintf(fp, "\n");
- } else if ((mi->memtype == KVADDR) && (task = stkptr_to_task(vaddr))
&&
+ } else if (((mi->memtype == KVADDR) || (mi->memtype == PHYSADDR)) &&
+ (task = stkptr_to_task(vaddr)) &&
(tc = task_to_context(task))) {
show_context(tc);
fprintf(fp, "\n");
--
2.33.1
952
days inactive
952
days old
devel@lists.crash-utility.osci.io
4 comments
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Tao Liu