add -s option to vm to display one vma at a time
 

Hello Dave,

When I am using "vm -p" command, I feel it is chaotic when too much data
is printed. I think it is clear to display one vma each time.


In the patch, I compare all vmas with the argument of -s option. If an
equal vma is found, it will be printed like below.


crash> vm -ps ffff88028ff7d3a0
VMA START END FLAGS FILE
ffff88028ff7d3a0 7fff29b71000 7fff29b87000 100173
VIRTUAL PHYSICAL
7fff29b71000 (not mapped)
7fff29b72000 (not mapped)
7fff29b73000 (not mapped)
7fff29b74000 (not mapped)
7fff29b75000 (not mapped)
7fff29b76000 (not mapped)
7fff29b77000 27faad000
7fff29b78000 2807aa000
7fff29b79000 280781000
7fff29b7a000 280787000
7fff29b7b000 280776000
7fff29b7c000 280786000
7fff29b7d000 27f2df000
7fff29b7e000 27f2e0000
7fff29b7f000 27f2e1000
7fff29b80000 27f2d7000
7fff29b81000 28b1ac000
7fff29b82000 28ecc1000
7fff29b83000 28c5c2000
7fff29b84000 28aaf4000
7fff29b85000 28aaf9000
7fff29b86000 289566000
crash>

--
--
Regards
Qiao Nuohan


diff --git a/defs.h b/defs.h
index a942dbb..f3ca47b 100755
--- a/defs.h
+++ b/defs.h
@@ -2241,6 +2241,7 @@ struct load_module {
#define PRINT_INODES (0x10) /* KVADDR, UVADDR, and PHYSADDR */
#define PRINT_MM_STRUCT (0x20)
#define PRINT_VMA_STRUCTS (0x40)
+#define PRINT_SINGLE_VMA (0x80)

#define MIN_PAGE_SIZE (4096)

diff --git a/memory.c b/memory.c
index 55a184b..d3ac2dc 100755
--- a/memory.c
+++ b/memory.c
@@ -3045,7 +3045,7 @@ cmd_vm(void)
ref = NULL;
BZERO(&reference, sizeof(struct reference));

- while ((c = getopt(argcnt, args, "f:pmvR:")) != EOF) {
+ while ((c = getopt(argcnt, args, "f:pmvR:s:")) != EOF) {
switch(c)
{
case 'f':
@@ -3059,13 +3059,13 @@ cmd_vm(void)
break;

case 'p':
- if (flag)
+ if (flag & ~PRINT_SINGLE_VMA)
argerrs++;
else
flag |= PHYSADDR;
break;
case 'm':
- if (flag)
+ if (flag & ~PRINT_SINGLE_VMA)
argerrs++;
else
flag |= PRINT_MM_STRUCT;
@@ -3090,6 +3090,17 @@ cmd_vm(void)
}
break;

+ case 's':
+ if ((flag & PRINT_MM_STRUCT) || ref) {
+ error(INFO, "-s option is only valid with -p/-v");
+ argerrs++;
+ } else {
+ flag |= PRINT_SINGLE_VMA;
+ ref = &reference;
+ ref->hexval = htol(optarg, FAULT_ON_ERROR, NULL);
+ }
+ break;
+
default:
argerrs++;
break;
@@ -3388,6 +3399,8 @@ vm_area_dump(ulong task, ulong flag, ulong vaddr, struct reference *ref)
ulonglong vm_flags;
ulong vm_file, inode;
ulong dentry, vfsmnt;
+ ulong single_vma;
+ int single_vma_header;
int found;
struct task_mem_usage task_mem_usage, *tm;
char buf1[BUFSIZE];
@@ -3401,6 +3414,12 @@ vm_area_dump(ulong task, ulong flag, ulong vaddr, struct reference *ref)
tm = &task_mem_usage;
get_task_mem_usage(task, tm);

+ single_vma_header = 0;
+ if (flag & PRINT_SINGLE_VMA) {
+ single_vma = ref->hexval;
+ ref = NULL;
+ }
+
if (ref) {
ref->cmdflags = VM_REF_SEARCH;
if (IS_A_NUMBER(ref->str)) {
@@ -3420,7 +3439,7 @@ vm_area_dump(ulong task, ulong flag, ulong vaddr, struct reference *ref)
return (ulong)NULL;
}

- if (!(flag & (UVADDR|PRINT_MM_STRUCT|PRINT_VMA_STRUCTS)) &&
+ if (!(flag & (UVADDR|PRINT_MM_STRUCT|PRINT_VMA_STRUCTS|PRINT_SI NGLE_VMA)) &&
!DO_REF_SEARCH(ref))
PRINT_VM_DATA();

@@ -3449,7 +3468,7 @@ vm_area_dump(ulong task, ulong flag, ulong vaddr, struct reference *ref)

for (found = FALSE; vma; vma = vm_next) {

- if ((flag & PHYSADDR) && !DO_REF_SEARCH(ref))
+ if ((flag & PHYSADDR) && !DO_REF_SEARCH(ref) && !single_vma_header)
fprintf(fp, "%s", vma_header);

inode = 0;
@@ -3462,6 +3481,12 @@ vm_area_dump(ulong task, ulong flag, ulong vaddr, struct reference *ref)
vm_start = ULONG(vma_buf + OFFSET(vm_area_struct_vm_start));
vm_flags = get_vm_flags(vma_buf);
vm_file = ULONG(vma_buf + OFFSET(vm_area_struct_vm_file));
+
+ if (flag & PRINT_SINGLE_VMA) {
+ single_vma_header++;
+ if (vma != single_vma)
+ continue;
+ }

if (flag & PRINT_VMA_STRUCTS) {
dump_struct("vm_area_struct", vma, 0);
--
Crash-utility mailing list
Crash-utility@redhat.com
https://www.redhat.com/mailman/listinfo/crash-utility

add -s option to vm to display one vma at a time
 

At 2012-3-14 4:45, Dave Anderson wrote:



----- Original Message -----

At 2012-3-13 17:56, qiaonuohan wrote:

Hello Dave,

When I am using "vm -p" command, I feel it is chaotic when too
much data is printed. I think it is clear to display one vma
each time.

In the patch, I compare all vmas with the argument of -s option.
If an equal vma is found, it will be printed like below.

crash> vm -ps ffff88028ff7d3a0
VMA START END FLAGS FILE
ffff88028ff7d3a0 7fff29b71000 7fff29b87000 100173
VIRTUAL PHYSICAL
7fff29b71000 (not mapped)
7fff29b72000 (not mapped)
7fff29b73000 (not mapped)
7fff29b74000 (not mapped)
7fff29b75000 (not mapped)
7fff29b76000 (not mapped)
7fff29b77000 27faad000
7fff29b78000 2807aa000
7fff29b79000 280781000
7fff29b7a000 280787000
7fff29b7b000 280776000
7fff29b7c000 280786000
7fff29b7d000 27f2df000
7fff29b7e000 27f2e0000
7fff29b7f000 27f2e1000
7fff29b80000 27f2d7000
7fff29b81000 28b1ac000
7fff29b82000 28ecc1000
7fff29b83000 28c5c2000
7fff29b84000 28aaf4000
7fff29b85000 28aaf9000
7fff29b86000 289566000
crash>


Seems like a reasonable request.

However, I don't like your mixing it with the "-R reference" usage,
because it confuses things like this simple example:

crash> vm -p -s ffff810ec9f57818
VMA START END FLAGS FILE
ffff810ec9f57818 4010d000 40110000 101877 /usr/local/java/jdk1.5.0_19/bin/java
VIRTUAL PHYSICAL
4010d000 ec89b1000
4010e000 FILE: /usr/local/java/jdk1.5.0_19/bin/java OFFSET: e000
4010f000 e99803000
crash>

If the command above were to be qualified with a "-R 4010e000" reference
check, it results in a nonsensical error message:

crash> vm -p -s ffff810ec9f57818 -R 4010e000
vm: only one -R option allowed
Usage:
vm [-p | -v | -m | [-R reference] | [-f vm_flags]] [pid | taskp] ...
Enter "help vm" for details.
crash>

A few suggestions:

(1) Don't even bother to tie it in with the "vm -v" option, because if
you already know the vm_area_struct address, then just print it with
"vm_area_struct<address>".

(2) Then, since it *only* applies with the -p functionality, make it
a new "-P<vmaddr>" option, where the help page explains that the
<vmaddr> argument must be a vm_area_struct of the current context:

Usage:
vm [-p | -P vmaddr | -v | -m | [-R reference] | [-f vm_flags]] [pid | taskp] ...

(3) Make -P mutually exclusive with all of the other options.

(4) Do not use the reference structure for this feature. Just use your new
flag, and pass the vma address in the 3rd "vaddr" argument to vm_area_dump(),
since it's not even being used by cmd_vm().


I have modified the patch, please check.

I need to refer one more think. Yesterday, I sent the modified patch
used to fix the problem of "swap/mount/file/...", please check it.




Dave


--
Crash-utility mailing list
Crash-utility@redhat.com
https://www.redhat.com/mailman/listinfo/crash-utility





--
--
Regards
Qiao Nuohan
diff --git a/defs.h b/defs.h
index a942dbb..f3ca47b 100755
--- a/defs.h
+++ b/defs.h
@@ -2241,6 +2241,7 @@ struct load_module {
#define PRINT_INODES (0x10) /* KVADDR, UVADDR, and PHYSADDR */
#define PRINT_MM_STRUCT (0x20)
#define PRINT_VMA_STRUCTS (0x40)
+#define PRINT_SINGLE_VMA (0x80)

#define MIN_PAGE_SIZE (4096)

diff --git a/help.c b/help.c
index f752283..562d42b 100755
--- a/help.c
+++ b/help.c
@@ -3108,7 +3108,7 @@ NULL
char *help_vm[] = {
"vm",
"virtual memory",
-"[-p | -v | -m | [-R reference] | [-f vm_flags]] [pid | taskp] ... ",
+"[-p | -P vmaddr | -v | -m | [-R reference] | [-f vm_flags]] [pid | taskp] ... ",
" This command displays basic virtual memory information of a context,",
" consisting of a pointer to its mm_struct and page dirctory, its RSS and ",
" total virtual memory size; and a list of pointers to each vm_area_struct,",
@@ -3124,6 +3124,8 @@ char *help_vm[] = {
" -p translate each virtual page to its physical address, or if",
" the page is not mapped, its swap device and offset, or",
" filename and offset.",
+" -P vmaddr translate each virtual page of the specified VM area to its",
+" physical address, the output is like -p option.",
" -R reference search for references to this number or filename.",
" -m dump the mm_struct assocated with the task.",
" -v dump all of the vm_area_structs associated with the task.",
@@ -3302,6 +3304,18 @@ char *help_vm[] = {
" Translate a FLAGS value:
",
" %s> vm -f 3875",
" 3875: (READ|EXEC|MAYREAD|MAYWRITE|MAYEXEC|DENYWRITE|EXEC UTABLE|LOCKED)",
+" ",
+" Display the page translations of VM area ffff8802953b22d8:
",
+" %s> vm -P ffff8802953b22d8",
+" VMA START END FLAGS FILE",
+" ffff8802953b22d8 300b000000 300b015000 8000075 /lib64/libz.so.1.2.3",
+" VIRTUAL PHYSICAL ",
+" 300b000000 28778c000",
+" 300b001000 28778d000",
+" 300b002000 FILE: /lib64/libz.so.1.2.3 OFFSET: 2000",
+" 300b003000 FILE: /lib64/libz.so.1.2.3 OFFSET: 3000",
+" 300b004000 FILE: /lib64/libz.so.1.2.3 OFFSET: 4000",
+" ...",
NULL
};

diff --git a/memory.c b/memory.c
index 55a184b..27c2f4e 100755
--- a/memory.c
+++ b/memory.c
@@ -3036,16 +3036,18 @@ cmd_vm(void)
int c;
ulong flag;
ulong value;
+ ulong single_vma;
ulonglong llvalue;
struct task_context *tc;
struct reference reference, *ref;
int subsequent;

flag = 0;
+ single_vma = 0;
ref = NULL;
BZERO(&reference, sizeof(struct reference));

- while ((c = getopt(argcnt, args, "f:pmvR:")) != EOF) {
+ while ((c = getopt(argcnt, args, "f:pmvR:P:")) != EOF) {
switch(c)
{
case 'f':
@@ -3090,6 +3092,15 @@ cmd_vm(void)
}
break;

+ case 'P':
+ if (flag) {
+ argerrs++;
+ } else {
+ flag |= PRINT_SINGLE_VMA;
+ single_vma = htol(optarg, FAULT_ON_ERROR, NULL);
+ }
+ break;
+
default:
argerrs++;
break;
@@ -3100,9 +3111,9 @@ cmd_vm(void)
cmd_usage(pc->curcmd, SYNOPSIS);

if (!args[optind]) {
- if (!ref)
+ if (!(ref || (flag & PRINT_SINGLE_VMA)))
print_task_header(fp, CURRENT_CONTEXT(), 0);
- vm_area_dump(CURRENT_TASK(), flag, 0, ref);
+ vm_area_dump(CURRENT_TASK(), flag, single_vma, ref);
return;
}

@@ -3113,16 +3124,16 @@ cmd_vm(void)
{
case STR_PID:
for (tc = pid_to_context(value); tc; tc = tc->tc_next) {
- if (!ref)
+ if (!(ref || (flag & PRINT_SINGLE_VMA)))
print_task_header(fp, tc, subsequent++);
- vm_area_dump(tc->task, flag, 0, ref);
+ vm_area_dump(tc->task, flag, single_vma, ref);
}
break;

case STR_TASK:
- if (!ref)
+ if (!(ref || (flag & PRINT_SINGLE_VMA)))
print_task_header(fp, tc, subsequent++);
- vm_area_dump(tc->task, flag, 0, ref);
+ vm_area_dump(tc->task, flag, single_vma, ref);
break;

case STR_INVALID:
@@ -3388,6 +3399,8 @@ vm_area_dump(ulong task, ulong flag, ulong vaddr, struct reference *ref)
ulonglong vm_flags;
ulong vm_file, inode;
ulong dentry, vfsmnt;
+ ulong single_vma;
+ int single_vma_header;
int found;
struct task_mem_usage task_mem_usage, *tm;
char buf1[BUFSIZE];
@@ -3401,6 +3414,13 @@ vm_area_dump(ulong task, ulong flag, ulong vaddr, struct reference *ref)
tm = &task_mem_usage;
get_task_mem_usage(task, tm);

+ single_vma_header = 0;
+ if (flag & PRINT_SINGLE_VMA) {
+ flag |= PHYSADDR;
+ single_vma = vaddr;
+ vaddr = 0;
+ }
+
if (ref) {
ref->cmdflags = VM_REF_SEARCH;
if (IS_A_NUMBER(ref->str)) {
@@ -3420,7 +3440,7 @@ vm_area_dump(ulong task, ulong flag, ulong vaddr, struct reference *ref)
return (ulong)NULL;
}

- if (!(flag & (UVADDR|PRINT_MM_STRUCT|PRINT_VMA_STRUCTS)) &&
+ if (!(flag & (UVADDR|PRINT_MM_STRUCT|PRINT_VMA_STRUCTS|PRINT_SI NGLE_VMA)) &&
!DO_REF_SEARCH(ref))
PRINT_VM_DATA();

@@ -3449,7 +3469,7 @@ vm_area_dump(ulong task, ulong flag, ulong vaddr, struct reference *ref)

for (found = FALSE; vma; vma = vm_next) {

- if ((flag & PHYSADDR) && !DO_REF_SEARCH(ref))
+ if ((flag & PHYSADDR) && !DO_REF_SEARCH(ref) && !single_vma_header)
fprintf(fp, "%s", vma_header);

inode = 0;
@@ -3462,6 +3482,12 @@ vm_area_dump(ulong task, ulong flag, ulong vaddr, struct reference *ref)
vm_start = ULONG(vma_buf + OFFSET(vm_area_struct_vm_start));
vm_flags = get_vm_flags(vma_buf);
vm_file = ULONG(vma_buf + OFFSET(vm_area_struct_vm_file));
+
+ if (flag & PRINT_SINGLE_VMA) {
+ single_vma_header++;
+ if (vma != single_vma)
+ continue;
+ }

if (flag & PRINT_VMA_STRUCTS) {
dump_struct("vm_area_struct", vma, 0);
--
Crash-utility mailing list
Crash-utility@redhat.com
https://www.redhat.com/mailman/listinfo/crash-utility

add -s option to vm to display one vma at a time
 

At 2012-3-15 3:06, Dave Anderson wrote:



----- Original Message -----

At 2012-3-14 4:45, Dave Anderson wrote:



----- Original Message -----

At 2012-3-13 17:56, qiaonuohan wrote:

Hello Dave,

When I am using "vm -p" command, I feel it is chaotic when too
much data is printed. I think it is clear to display one vma
each time.

In the patch, I compare all vmas with the argument of -s option.
If an equal vma is found, it will be printed like below.

crash> vm -ps ffff88028ff7d3a0
VMA START END FLAGS FILE
ffff88028ff7d3a0 7fff29b71000 7fff29b87000 100173
VIRTUAL PHYSICAL
7fff29b71000 (not mapped)
7fff29b72000 (not mapped)
7fff29b73000 (not mapped)
7fff29b74000 (not mapped)
7fff29b75000 (not mapped)
7fff29b76000 (not mapped)
7fff29b77000 27faad000
7fff29b78000 2807aa000
7fff29b79000 280781000
7fff29b7a000 280787000
7fff29b7b000 280776000
7fff29b7c000 280786000
7fff29b7d000 27f2df000
7fff29b7e000 27f2e0000
7fff29b7f000 27f2e1000
7fff29b80000 27f2d7000
7fff29b81000 28b1ac000
7fff29b82000 28ecc1000
7fff29b83000 28c5c2000
7fff29b84000 28aaf4000
7fff29b85000 28aaf9000
7fff29b86000 289566000
crash>


Seems like a reasonable request.

However, I don't like your mixing it with the "-R reference" usage,
because it confuses things like this simple example:

crash> vm -p -s ffff810ec9f57818
VMA START END FLAGS FILE
ffff810ec9f57818 4010d000 40110000 101877 /usr/local/java/jdk1.5.0_19/bin/java
VIRTUAL PHYSICAL
4010d000 ec89b1000
4010e000 FILE: /usr/local/java/jdk1.5.0_19/bin/java OFFSET: e000
4010f000 e99803000
crash>

If the command above were to be qualified with a "-R 4010e000" reference
check, it results in a nonsensical error message:

crash> vm -p -s ffff810ec9f57818 -R 4010e000
vm: only one -R option allowed
Usage:
vm [-p | -v | -m | [-R reference] | [-f vm_flags]] [pid |
taskp] ...
Enter "help vm" for details.
crash>

A few suggestions:

(1) Don't even bother to tie it in with the "vm -v" option, because if
you already know the vm_area_struct address, then just print it with
"vm_area_struct<address>".

(2) Then, since it *only* applies with the -p functionality, make it
a new "-P<vmaddr>" option, where the help page explains that the
<vmaddr> argument must be a vm_area_struct of the current context:

Usage:
vm [-p | -P vmaddr | -v | -m | [-R reference] | [-f
vm_flags]] [pid | taskp] ...

(3) Make -P mutually exclusive with all of the other options.

(4) Do not use the reference structure for this feature. Just use your new
flag, and pass the vma address in the 3rd "vaddr" argument to vm_area_dump(),
since it's not even being used by cmd_vm().


I have modified the patch, please check.


OK, these are my suggestions to finalize this patch. First, fix this:

# make warn
...
cc -c -g -DX86_64 -DGDB_7_3_1 memory.c -Wall -O2 -Wstrict-prototypes -Wmissing-prototypes -fstack-protector
memory.c: In function "vm_area_dump":
memory.c:3503:7: warning: "single_vma" may be used uninitialized in this function [-Wuninitialized]
...

Secondly, this command is no different from the other context-sensitive
"vm" command options, so please always print the task header like they
do. Just remove the three restrictions in cmd_vm() that do this:

- if (!ref)
+ if (!(ref || (flag& PRINT_SINGLE_VMA)))
print_task_header(fp, CURRENT_CONTEXT(), 0);

Third, the option is either going to work OK or fail to find the VMA.
Your patch does this if an invalid vm_area_struct address is entered:

crash> vm -P ffff880617e7af44
VMA START END FLAGS FILE
crash>

Regardless of success or failure, the print_task_header() call in cmd_vm()
should always show the task information. Then, if you actually find the VMA,
print the "VMA START ..." header along with its data:

crash> vm -P ffff880284cf87e0
PID: 13318 TASK: ffff8806294f2690 CPU: 11 COMMAND: "crash"
VMA START END FLAGS FILE
ffff880284cf87e0 400000 9fa000 8001875 /root/crash-6.0.4/crash
VIRTUAL PHYSICAL
400000 28c7fa000
401000 29470a000
402000 29470b000
403000 29470c000
404000 29470d000
405000 29470e000
406000 29470f000
...

But if the command fails to find the VMA, then indicate that under
the task header:

crash> vm -P ffff880284cf87e8
PID: 13318 TASK: ffff8806294f2690 CPU: 11 COMMAND: "crash"
(not found)
crash>

Lastly, please don't use subterfuge to accomplish the task at
hand. The setting of PHYSADDR in the vm_area_dump() function
makes no sense at all:

+ single_vma_header = 0;
+ if (flag& PRINT_SINGLE_VMA) {
+ flag |= PHYSADDR;
+ single_vma = vaddr;
+ vaddr = 0;
+ }

It may "work" by doing the above, but I'm sure you can accomplish
it just as easily using your PRINT_SINGLE_VMA flag and/or your new
local variables, making it both easier to understand and more
maintainable.


The patch is modified. I think I need to pay more attention to
maintainable and thanks for your patience.




Thanks,
Dave

--
Crash-utility mailing list
Crash-utility@redhat.com
https://www.redhat.com/mailman/listinfo/crash-utility





--
--
Regards
Qiao Nuohan
--
Crash-utility mailing list
Crash-utility@redhat.com
https://www.redhat.com/mailman/listinfo/crash-utility