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EXPERT Kconfig menu: fix broken EXPERT menu
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Clean up the EXPERT menu (yet again).

Move FHANDLE and CHECKPOINT_RESTORE into the primary EXPERT menu since
they already depend on EXPERT.

Move BPF_SYSCALL and USERFAULTFD out of the EXPERT Kconfig symbols menu
list since they do not depend on EXPERT and were breaking the continuity
of that menu list.

Move all of the KALLSYMS Kconfig symbols to the end of the EXPERT menu.
This separates the kernel services from the build options.

This patch depends on [PATCH] pci: move PCI_QUIRKS to the PCI bus menu
(https://lkml.org/lkml/2017/11/2/907).

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Randy Dunlap <[email protected]>
Acked-by: Daniel Borkmann <[email protected]>	[BPF]
Cc: Andrea Arcangeli <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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@rddunlap @torvalds
rddunlap authored and torvalds committed Nov 18, 2017
1 parent 7016383 commit d1b069f
Showing 1 changed file with 93 additions and 91 deletions.
184 changes: 93 additions & 91 deletions init/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -283,19 +283,6 @@ config CROSS_MEMORY_ATTACH
to directly read from or write to another process' address space.
See the man page for more details.

config FHANDLE
bool "open by fhandle syscalls" if EXPERT
select EXPORTFS
default y
help
If you say Y here, a user level program will be able to map
file names to handle and then later use the handle for
different file system operations. This is useful in implementing
userspace file servers, which now track files using handles instead
of names. The handle would remain the same even if file names
get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
syscalls.

config USELIB
bool "uselib syscall"
def_bool ALPHA || M68K || SPARC || X86_32 || IA32_EMULATION
Expand Down Expand Up @@ -883,18 +870,6 @@ config SOCK_CGROUP_DATA

endif # CGROUPS

config CHECKPOINT_RESTORE
bool "Checkpoint/restore support" if EXPERT
select PROC_CHILDREN
default n
help
Enables additional kernel features in a sake of checkpoint/restore.
In particular it adds auxiliary prctl codes to setup process text,
data and heap segment sizes, and a few additional /proc filesystem
entries.

If unsure, say N here.

menuconfig NAMESPACES
bool "Namespaces support" if EXPERT
depends on MULTIUSER
Expand Down Expand Up @@ -1163,6 +1138,19 @@ config SYSCTL_SYSCALL

If unsure say N here.

config FHANDLE
bool "open by fhandle syscalls" if EXPERT
select EXPORTFS
default y
help
If you say Y here, a user level program will be able to map
file names to handle and then later use the handle for
different file system operations. This is useful in implementing
userspace file servers, which now track files using handles instead
of names. The handle would remain the same even if file names
get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
syscalls.

config POSIX_TIMERS
bool "Posix Clocks & timers" if EXPERT
default y
Expand All @@ -1180,54 +1168,6 @@ config POSIX_TIMERS

If unsure say y.

config KALLSYMS
bool "Load all symbols for debugging/ksymoops" if EXPERT
default y
help
Say Y here to let the kernel print out symbolic crash information and
symbolic stack backtraces. This increases the size of the kernel
somewhat, as all symbols have to be loaded into the kernel image.

config KALLSYMS_ALL
bool "Include all symbols in kallsyms"
depends on DEBUG_KERNEL && KALLSYMS
help
Normally kallsyms only contains the symbols of functions for nicer
OOPS messages and backtraces (i.e., symbols from the text and inittext
sections). This is sufficient for most cases. And only in very rare
cases (e.g., when a debugger is used) all symbols are required (e.g.,
names of variables from the data sections, etc).

This option makes sure that all symbols are loaded into the kernel
image (i.e., symbols from all sections) in cost of increased kernel
size (depending on the kernel configuration, it may be 300KiB or
something like this).

Say N unless you really need all symbols.

config KALLSYMS_ABSOLUTE_PERCPU
bool
depends on KALLSYMS
default X86_64 && SMP

config KALLSYMS_BASE_RELATIVE
bool
depends on KALLSYMS
default !IA64 && !(TILE && 64BIT)
help
Instead of emitting them as absolute values in the native word size,
emit the symbol references in the kallsyms table as 32-bit entries,
each containing a relative value in the range [base, base + U32_MAX]
or, when KALLSYMS_ABSOLUTE_PERCPU is in effect, each containing either
an absolute value in the range [0, S32_MAX] or a relative value in the
range [base, base + S32_MAX], where base is the lowest relative symbol
address encountered in the image.

On 64-bit builds, this reduces the size of the address table by 50%,
but more importantly, it results in entries whose values are build
time constants, and no relocation pass is required at runtime to fix
up the entries based on the runtime load address of the kernel.

config PRINTK
default y
bool "Enable support for printk" if EXPERT
Expand Down Expand Up @@ -1339,16 +1279,6 @@ config EVENTFD

If unsure, say Y.

# syscall, maps, verifier
config BPF_SYSCALL
bool "Enable bpf() system call"
select ANON_INODES
select BPF
default n
help
Enable the bpf() system call that allows to manipulate eBPF
programs and maps via file descriptors.

config SHMEM
bool "Use full shmem filesystem" if EXPERT
default y
Expand Down Expand Up @@ -1378,14 +1308,6 @@ config ADVISE_SYSCALLS
applications use these syscalls, you can disable this option to save
space.

config USERFAULTFD
bool "Enable userfaultfd() system call"
select ANON_INODES
depends on MMU
help
Enable the userfaultfd() system call that allows to intercept and
handle page faults in userland.

config MEMBARRIER
bool "Enable membarrier() system call" if EXPERT
default y
Expand All @@ -1398,6 +1320,86 @@ config MEMBARRIER

If unsure, say Y.

config CHECKPOINT_RESTORE
bool "Checkpoint/restore support" if EXPERT
select PROC_CHILDREN
default n
help
Enables additional kernel features in a sake of checkpoint/restore.
In particular it adds auxiliary prctl codes to setup process text,
data and heap segment sizes, and a few additional /proc filesystem
entries.

If unsure, say N here.

config KALLSYMS
bool "Load all symbols for debugging/ksymoops" if EXPERT
default y
help
Say Y here to let the kernel print out symbolic crash information and
symbolic stack backtraces. This increases the size of the kernel
somewhat, as all symbols have to be loaded into the kernel image.

config KALLSYMS_ALL
bool "Include all symbols in kallsyms"
depends on DEBUG_KERNEL && KALLSYMS
help
Normally kallsyms only contains the symbols of functions for nicer
OOPS messages and backtraces (i.e., symbols from the text and inittext
sections). This is sufficient for most cases. And only in very rare
cases (e.g., when a debugger is used) all symbols are required (e.g.,
names of variables from the data sections, etc).

This option makes sure that all symbols are loaded into the kernel
image (i.e., symbols from all sections) in cost of increased kernel
size (depending on the kernel configuration, it may be 300KiB or
something like this).

Say N unless you really need all symbols.

config KALLSYMS_ABSOLUTE_PERCPU
bool
depends on KALLSYMS
default X86_64 && SMP

config KALLSYMS_BASE_RELATIVE
bool
depends on KALLSYMS
default !IA64 && !(TILE && 64BIT)
help
Instead of emitting them as absolute values in the native word size,
emit the symbol references in the kallsyms table as 32-bit entries,
each containing a relative value in the range [base, base + U32_MAX]
or, when KALLSYMS_ABSOLUTE_PERCPU is in effect, each containing either
an absolute value in the range [0, S32_MAX] or a relative value in the
range [base, base + S32_MAX], where base is the lowest relative symbol
address encountered in the image.

On 64-bit builds, this reduces the size of the address table by 50%,
but more importantly, it results in entries whose values are build
time constants, and no relocation pass is required at runtime to fix
up the entries based on the runtime load address of the kernel.

# end of the "standard kernel features (expert users)" menu

# syscall, maps, verifier
config BPF_SYSCALL
bool "Enable bpf() system call"
select ANON_INODES
select BPF
default n
help
Enable the bpf() system call that allows to manipulate eBPF
programs and maps via file descriptors.

config USERFAULTFD
bool "Enable userfaultfd() system call"
select ANON_INODES
depends on MMU
help
Enable the userfaultfd() system call that allows to intercept and
handle page faults in userland.

config EMBEDDED
bool "Embedded system"
option allnoconfig_y
Expand Down

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