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freebsd-nq/share/man/man4/ksyms.4

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mdoc: consistently spell our email addresses <foo@FreeBSD.org> Reviewed by: ru
2010-05-19 08:57:53 +00:00
.\" Copyright (c) 2008-2009 Stacey Son <sson@FreeBSD.org>
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
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.Dd April 5, 2009
.Dt KSYMS 4
.Os
.Sh NAME
.Nm ksyms
.Nd kernel symbol table interface
.Sh SYNOPSIS
.Cd "device ksyms"
.Sh DESCRIPTION
The
.Pa /dev/ksyms
Remove trailing whitespace per mdoc lint warning Disussed with: gavin No objection from: doc Approved by: joel MFC after: 3 days
2012-03-29 05:02:12 +00:00
character device provides a read-only interface to a snapshot of the kernel
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
symbol table. The in-kernel symbol manager is designed to be able to handle
Remove trailing whitespace per mdoc lint warning Disussed with: gavin No objection from: doc Approved by: joel MFC after: 3 days
2012-03-29 05:02:12 +00:00
many types of symbols tables, however, only
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
.Xr elf 5
symbol tables are supported by this device. The ELF format image contains two
Remove trailing whitespace per mdoc lint warning Disussed with: gavin No objection from: doc Approved by: joel MFC after: 3 days
2012-03-29 05:02:12 +00:00
sections: a symbol table and a corresponding string table.
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
.Bl -tag -width indent -offset indent
.It Dv Symbol Table
Remove trailing whitespace per mdoc lint warning Disussed with: gavin No objection from: doc Approved by: joel MFC after: 3 days
2012-03-29 05:02:12 +00:00
The SYMTAB section contains the symbol table entries present in the current
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
running kernel, including the symbol table entries of any loaded modules. The
symbols are ordered by the kernel module load time starting with kernel file
symbols first, followed by the first loaded module's symbols and so on.
.It Dv String Table
The STRTAB section contains the symbol name strings from the kernel and any
loaded modules that the symbol table entries reference.
.El
.Pp
Fix a bunch of typos and spelling mistakes.
2010-07-31 12:14:28 +00:00
Elf formatted symbol table data read from the
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
.Pa /dev/ksyms
file represents the state of the kernel at the time when the device is opened.
Since
.Pa /dev/ksyms
has no text or data, most of the fields are initialized to NULL.
Remove trailing whitespace per mdoc lint warning Disussed with: gavin No objection from: doc Approved by: joel MFC after: 3 days
2012-03-29 05:02:12 +00:00
The
.Nm
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
driver does not block the loading or unloading of modules into the kernel
Remove trailing whitespace per mdoc lint warning Disussed with: gavin No objection from: doc Approved by: joel MFC after: 3 days
2012-03-29 05:02:12 +00:00
while the
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
.Pa /dev/ksyms
file is open but may contain stale data.
.Sh IOCTLS
The
.Xr ioctl 2
command codes below are defined in
.Aq Pa sys/ksyms.h .
.Pp
The (third) argument to the
.Xr ioctl 2
should be a pointer to the type indicated.
.Bl -tag -width indent -offset indent
.It Dv KIOCGSIZE (size_t)
Returns the total size of the current symbol table.
This can be used when allocating a buffer to make a copy of
the kernel symbol table.
.It Dv KIOCGADDR (void *)
Returns the address of the kernel symbol table mapped in
Remove trailing whitespace per mdoc lint warning Disussed with: gavin No objection from: doc Approved by: joel MFC after: 3 days
2012-03-29 05:02:12 +00:00
the process memory.
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
.El
.Sh FILES
.Bl -tag -width /dev/ksymsX
.It Pa /dev/ksyms
.El
.Sh ERRORS
Remove trailing whitespace per mdoc lint warning Disussed with: gavin No objection from: doc Approved by: joel MFC after: 3 days
2012-03-29 05:02:12 +00:00
An
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
.Xr open 2
of
.Pa /dev/ksyms
Remove trailing whitespace per mdoc lint warning Disussed with: gavin No objection from: doc Approved by: joel MFC after: 3 days
2012-03-29 05:02:12 +00:00
will fail if:
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
.Bl -tag -width Er
.It Bq Er EBUSY
Remove trailing whitespace per mdoc lint warning Disussed with: gavin No objection from: doc Approved by: joel MFC after: 3 days
2012-03-29 05:02:12 +00:00
The device is already open. A process must close
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
.Pa /dev/ksyms
Remove trailing whitespace per mdoc lint warning Disussed with: gavin No objection from: doc Approved by: joel MFC after: 3 days
2012-03-29 05:02:12 +00:00
before it can be opened again.
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
.It Bq Er ENOMEM
There is a resource shortage in the kernel.
.It Bq Er ENXIO
The driver was unsuccessful in creating a snapshot of the kernel symbol
table. This may occur if the kernel was in the process of loading or
Remove trailing whitespace per mdoc lint warning Disussed with: gavin No objection from: doc Approved by: joel MFC after: 3 days
2012-03-29 05:02:12 +00:00
unloading a module.
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
.El
.Sh SEE ALSO
.Xr ioctl 2 ,
.Xr nlist 3 ,
.Xr elf 5 ,
.Xr kldload 8
.Sh HISTORY
A
.Nm
device exists in many different operating systems.
This implementation is similar in function to the Solaris and NetBSD
.Nm
driver.
.Pp
The
.Nm
driver first appeared in
.Fx 8.0
Remove trailing whitespace per mdoc lint warning Disussed with: gavin No objection from: doc Approved by: joel MFC after: 3 days
2012-03-29 05:02:12 +00:00
to support
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
.Xr lockstat 1 .
mdoc: move CAVEATS, BUGS and SECURITY CONSIDERATIONS sections to the bottom of the manpages and order them consistently. GNU groff doesn't care about the ordering, and doesn't even mention CAVEATS and SECURITY CONSIDERATIONS as common sections and where to put them. Found by: mdocml lint run Reviewed by: ru
2010-05-13 12:07:55 +00:00
.Sh AUTHORS
The
.Nm
driver was written by
.An Stacey Son
mdoc: consistently spell our email addresses <foo@FreeBSD.org> Reviewed by: ru
2010-05-19 08:57:53 +00:00
.Aq sson@FreeBSD.org .
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
.Sh BUGS
Remove trailing whitespace per mdoc lint warning Disussed with: gavin No objection from: doc Approved by: joel MFC after: 3 days
2012-03-29 05:02:12 +00:00
Because files can be dynamically linked into the kernel at any time the symbol
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
information can vary. When you open the
.Pa /dev/ksyms
file, you have access to an ELF image which represents a snapshot of the state of the kernel symbol information at that instant in time. Keeping the device open does not block the loading or unloading of kernel modules. To get a new snapshot you must close and re-open the device.
.Pp
A process is only allowed to open the
.Pa /dev/ksyms
file once at a time. The process must close the
.Pa /dev/ksyms
before it is allowed to open it again.
Remove trailing whitespace per mdoc lint warning Disussed with: gavin No objection from: doc Approved by: joel MFC after: 3 days
2012-03-29 05:02:12 +00:00
.Pp
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
The
.Nm
Remove trailing whitespace per mdoc lint warning Disussed with: gavin No objection from: doc Approved by: joel MFC after: 3 days
2012-03-29 05:02:12 +00:00
driver uses the calling process' memory address space to store the snapshot.
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
.Xr ioctl 2
can be used to get the memory address where the symbol table is stored to
Remove trailing whitespace per mdoc lint warning Disussed with: gavin No objection from: doc Approved by: joel MFC after: 3 days
2012-03-29 05:02:12 +00:00
save kernel memory.
Add the ksyms(4) pseudo driver. The ksyms driver allows a process to get a quick snapshot of the kernel's symbol table including the symbols from any loaded modules (the symbols are all merged into one symbol table). Unlike like other implementations, this ksyms driver maps memory in the process memory space to store the snapshot at the time /dev/ksyms is opened. It also checks to see if the process has already a snapshot open and won't allow it to open /dev/ksyms it again until it closes first. This prevents kernel and process memory from being exhausted. Note that /dev/ksyms is used by the lockstat(1) command. Reviewed by: gallatin kib (freebsd-arch) Approved by: gnn (mentor)
2009-05-26 21:39:09 +00:00
.Xr mmap 2
Remove trailing whitespace per mdoc lint warning Disussed with: gavin No objection from: doc Approved by: joel MFC after: 3 days
2012-03-29 05:02:12 +00:00
may also be used but it will map it to another address.
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