core dump — linux
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I'm trying to understand the core dump generation. Is the core dump generated separately for a user space application process crash and the kernel level crash? Is the ulimit -c for both kinds?
linux linux-kernel core-dump
edited Nov 25 at 23:43
Rui F Ribeiro
38.3k1477127
asked Mar 1 '13 at 6:32
foo_l
12514
add a comment |
up vote
3
down vote
favorite
I'm trying to understand the core dump generation. Is the core dump generated separately for a user space application process crash and the kernel level crash? Is the ulimit -c for both kinds?
linux linux-kernel core-dump
edited Nov 25 at 23:43
Rui F Ribeiro
38.3k1477127
asked Mar 1 '13 at 6:32
foo_l
12514
add a comment |
up vote
3
down vote
favorite
up vote
3
down vote
favorite
I'm trying to understand the core dump generation. Is the core dump generated separately for a user space application process crash and the kernel level crash? Is the ulimit -c for both kinds?
linux linux-kernel core-dump
edited Nov 25 at 23:43
Rui F Ribeiro
38.3k1477127
asked Mar 1 '13 at 6:32
foo_l
12514
I'm trying to understand the core dump generation. Is the core dump generated separately for a user space application process crash and the kernel level crash? Is the ulimit -c for both kinds?
linux linux-kernel core-dump
linux linux-kernel core-dump
edited Nov 25 at 23:43
Rui F Ribeiro
38.3k1477127
asked Mar 1 '13 at 6:32
foo_l
12514
edited Nov 25 at 23:43
Rui F Ribeiro
38.3k1477127
asked Mar 1 '13 at 6:32
foo_l
12514
edited Nov 25 at 23:43
Rui F Ribeiro
38.3k1477127
edited Nov 25 at 23:43
Rui F Ribeiro
38.3k1477127
edited Nov 25 at 23:43
Rui F Ribeiro
38.3k1477127
38.3k1477127
asked Mar 1 '13 at 6:32
foo_l
12514
asked Mar 1 '13 at 6:32
foo_l
12514
asked Mar 1 '13 at 6:32
foo_l
12514
12514
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
up vote
5
down vote
accepted
When a userland program crashes, it can leave a core file behind, containig a copy of the contents of the memory when it went down (the core name comes from the prehistory of computing, when memory was core). This is controlled by the ulimit(1) command, it is normally disabled as the core files are large and tend to confuse newbies. A core file can be analyzed by e.g. a debugger, together with the executable and symbol table, to find out what happened.
When the kernel crashes, it normally triggers a kernel panic. If the kernel has found some critical inconsistency, it really isn't wise to count on it bahaving sanely to write out anything. So no core gets generated, and the system goes down. Contents of registers and code surrounding the address where the problem happened is written to the console. It is a good idea to save this (e.g. take a picture) for possible later analysis.
A similar situation is the kernel Oops, when the kernel detects an inconsistency that isn't considered fatal. In that case (as in a kernel panic) contents of registers and code surrounding the address where the problem happened is written to the console, and also logged.
answered Mar 1 '13 at 13:26
vonbrand
14.1k22444
In my case the kernel version is2.4.20and it does not have theproc/sys/kernel/core_patternfile to specify my own path to dump the core file. Whenever I build the kernel(along with the application) and load the bin in my embedded system the current directory is always/and hence it is not able to generate the core dump when my application crashes,maybe due to the permissions issue. Is there any way that I can change the location of the core dump file or change the permissions of the/dir or change the current dir/to other dir say/tmp. Also there is nosysctl.conffile.
– foo_l
Mar 11 '13 at 6:37
The simplest may be to move the current working directory of the bin. If you can control how it starts, then firstcdto a directory other than/and start it from there. Otherwise, have the bin callchdir("/tmp")(or other dir) if you can. Changing permissions on/is possible, but may be unwise for security reasons.
– ash
Aug 28 '13 at 13:02
add a comment |
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
up vote
5
down vote
accepted
When a userland program crashes, it can leave a core file behind, containig a copy of the contents of the memory when it went down (the core name comes from the prehistory of computing, when memory was core). This is controlled by the ulimit(1) command, it is normally disabled as the core files are large and tend to confuse newbies. A core file can be analyzed by e.g. a debugger, together with the executable and symbol table, to find out what happened.
When the kernel crashes, it normally triggers a kernel panic. If the kernel has found some critical inconsistency, it really isn't wise to count on it bahaving sanely to write out anything. So no core gets generated, and the system goes down. Contents of registers and code surrounding the address where the problem happened is written to the console. It is a good idea to save this (e.g. take a picture) for possible later analysis.
A similar situation is the kernel Oops, when the kernel detects an inconsistency that isn't considered fatal. In that case (as in a kernel panic) contents of registers and code surrounding the address where the problem happened is written to the console, and also logged.
answered Mar 1 '13 at 13:26
vonbrand
14.1k22444
In my case the kernel version is2.4.20and it does not have theproc/sys/kernel/core_patternfile to specify my own path to dump the core file. Whenever I build the kernel(along with the application) and load the bin in my embedded system the current directory is always/and hence it is not able to generate the core dump when my application crashes,maybe due to the permissions issue. Is there any way that I can change the location of the core dump file or change the permissions of the/dir or change the current dir/to other dir say/tmp. Also there is nosysctl.conffile.
– foo_l
Mar 11 '13 at 6:37
The simplest may be to move the current working directory of the bin. If you can control how it starts, then firstcdto a directory other than/and start it from there. Otherwise, have the bin callchdir("/tmp")(or other dir) if you can. Changing permissions on/is possible, but may be unwise for security reasons.
– ash
Aug 28 '13 at 13:02
add a comment |
up vote
5
down vote
accepted
When a userland program crashes, it can leave a core file behind, containig a copy of the contents of the memory when it went down (the core name comes from the prehistory of computing, when memory was core). This is controlled by the ulimit(1) command, it is normally disabled as the core files are large and tend to confuse newbies. A core file can be analyzed by e.g. a debugger, together with the executable and symbol table, to find out what happened.
When the kernel crashes, it normally triggers a kernel panic. If the kernel has found some critical inconsistency, it really isn't wise to count on it bahaving sanely to write out anything. So no core gets generated, and the system goes down. Contents of registers and code surrounding the address where the problem happened is written to the console. It is a good idea to save this (e.g. take a picture) for possible later analysis.
A similar situation is the kernel Oops, when the kernel detects an inconsistency that isn't considered fatal. In that case (as in a kernel panic) contents of registers and code surrounding the address where the problem happened is written to the console, and also logged.
answered Mar 1 '13 at 13:26
vonbrand
14.1k22444
In my case the kernel version is2.4.20and it does not have theproc/sys/kernel/core_patternfile to specify my own path to dump the core file. Whenever I build the kernel(along with the application) and load the bin in my embedded system the current directory is always/and hence it is not able to generate the core dump when my application crashes,maybe due to the permissions issue. Is there any way that I can change the location of the core dump file or change the permissions of the/dir or change the current dir/to other dir say/tmp. Also there is nosysctl.conffile.
– foo_l
Mar 11 '13 at 6:37
The simplest may be to move the current working directory of the bin. If you can control how it starts, then firstcdto a directory other than/and start it from there. Otherwise, have the bin callchdir("/tmp")(or other dir) if you can. Changing permissions on/is possible, but may be unwise for security reasons.
– ash
Aug 28 '13 at 13:02
add a comment |
up vote
5
down vote
accepted
up vote
5
down vote
accepted
When a userland program crashes, it can leave a core file behind, containig a copy of the contents of the memory when it went down (the core name comes from the prehistory of computing, when memory was core). This is controlled by the ulimit(1) command, it is normally disabled as the core files are large and tend to confuse newbies. A core file can be analyzed by e.g. a debugger, together with the executable and symbol table, to find out what happened.
When the kernel crashes, it normally triggers a kernel panic. If the kernel has found some critical inconsistency, it really isn't wise to count on it bahaving sanely to write out anything. So no core gets generated, and the system goes down. Contents of registers and code surrounding the address where the problem happened is written to the console. It is a good idea to save this (e.g. take a picture) for possible later analysis.
A similar situation is the kernel Oops, when the kernel detects an inconsistency that isn't considered fatal. In that case (as in a kernel panic) contents of registers and code surrounding the address where the problem happened is written to the console, and also logged.
answered Mar 1 '13 at 13:26
vonbrand
14.1k22444
When a userland program crashes, it can leave a core file behind, containig a copy of the contents of the memory when it went down (the core name comes from the prehistory of computing, when memory was core). This is controlled by the ulimit(1) command, it is normally disabled as the core files are large and tend to confuse newbies. A core file can be analyzed by e.g. a debugger, together with the executable and symbol table, to find out what happened.
When the kernel crashes, it normally triggers a kernel panic. If the kernel has found some critical inconsistency, it really isn't wise to count on it bahaving sanely to write out anything. So no core gets generated, and the system goes down. Contents of registers and code surrounding the address where the problem happened is written to the console. It is a good idea to save this (e.g. take a picture) for possible later analysis.
A similar situation is the kernel Oops, when the kernel detects an inconsistency that isn't considered fatal. In that case (as in a kernel panic) contents of registers and code surrounding the address where the problem happened is written to the console, and also logged.
answered Mar 1 '13 at 13:26
vonbrand
14.1k22444
answered Mar 1 '13 at 13:26
vonbrand
14.1k22444
answered Mar 1 '13 at 13:26
vonbrand
14.1k22444
answered Mar 1 '13 at 13:26
vonbrand
14.1k22444
14.1k22444
In my case the kernel version is2.4.20and it does not have theproc/sys/kernel/core_patternfile to specify my own path to dump the core file. Whenever I build the kernel(along with the application) and load the bin in my embedded system the current directory is always/and hence it is not able to generate the core dump when my application crashes,maybe due to the permissions issue. Is there any way that I can change the location of the core dump file or change the permissions of the/dir or change the current dir/to other dir say/tmp. Also there is nosysctl.conffile.
– foo_l
Mar 11 '13 at 6:37
The simplest may be to move the current working directory of the bin. If you can control how it starts, then firstcdto a directory other than/and start it from there. Otherwise, have the bin callchdir("/tmp")(or other dir) if you can. Changing permissions on/is possible, but may be unwise for security reasons.
– ash
Aug 28 '13 at 13:02
add a comment |
In my case the kernel version is2.4.20and it does not have theproc/sys/kernel/core_patternfile to specify my own path to dump the core file. Whenever I build the kernel(along with the application) and load the bin in my embedded system the current directory is always/and hence it is not able to generate the core dump when my application crashes,maybe due to the permissions issue. Is there any way that I can change the location of the core dump file or change the permissions of the/dir or change the current dir/to other dir say/tmp. Also there is nosysctl.conffile.
– foo_l
Mar 11 '13 at 6:37
The simplest may be to move the current working directory of the bin. If you can control how it starts, then firstcdto a directory other than/and start it from there. Otherwise, have the bin callchdir("/tmp")(or other dir) if you can. Changing permissions on/is possible, but may be unwise for security reasons.
– ash
Aug 28 '13 at 13:02
In my case the kernel version is
2.4.20 and it does not have the proc/sys/kernel/core_pattern file to specify my own path to dump the core file. Whenever I build the kernel(along with the application) and load the bin in my embedded system the current directory is always / and hence it is not able to generate the core dump when my application crashes,maybe due to the permissions issue. Is there any way that I can change the location of the core dump file or change the permissions of the / dir or change the current dir / to other dir say /tmp. Also there is no sysctl.conf file.– foo_l
Mar 11 '13 at 6:37
In my case the kernel version is
2.4.20 and it does not have the proc/sys/kernel/core_pattern file to specify my own path to dump the core file. Whenever I build the kernel(along with the application) and load the bin in my embedded system the current directory is always / and hence it is not able to generate the core dump when my application crashes,maybe due to the permissions issue. Is there any way that I can change the location of the core dump file or change the permissions of the / dir or change the current dir / to other dir say /tmp. Also there is no sysctl.conf file.– foo_l
Mar 11 '13 at 6:37
The simplest may be to move the current working directory of the bin. If you can control how it starts, then first
cd to a directory other than / and start it from there. Otherwise, have the bin call chdir("/tmp") (or other dir) if you can. Changing permissions on / is possible, but may be unwise for security reasons.– ash
Aug 28 '13 at 13:02
The simplest may be to move the current working directory of the bin. If you can control how it starts, then first
cd to a directory other than / and start it from there. Otherwise, have the bin call chdir("/tmp") (or other dir) if you can. Changing permissions on / is possible, but may be unwise for security reasons.– ash
Aug 28 '13 at 13:02
add a comment |
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