Kernel: fix operator priority warning

Pointed by clang.

Change-Id: I16aa242c94abdf1fa22c4651e63c8c236e6c1a82
Reviewed-on: https://review.haiku-os.org/c/haiku/+/2393
Reviewed-by: John Scipione <jscipione@gmail.com>

Change instances of wether in comments to whether. No functional change intended.

Check if the name is already used in add_debugger_command*() and reject
duplicate attempt(s).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40611 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Fixed the semantics of [v]snprintf(): If the buffer is not large enough,
the function shall nevertheless return the length of the string that would
be written, if the buffer were large enough.
Added a touch of C++ while doing that. :-)
* Fixed the instances in boot loader, kernel, and kernel modules where the
wrong semantics were expected. The majority of uses actually.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34826 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Renamed the ROUNDOWN macro to ROUNDDOWN. Also changed the implementation of
ROUNDUP to use '*' and '/' -- the compiler will optimize that for powers of
two anyway and this implementation works for other numbers as well.
* The thread::fault_handler use in C[++] code was broken with gcc 4. At least
when other functions were invoked. Trying to trick the compiler wasn't a
particularly good idea anyway, since the next compiler version could break
the trick again. So the general policy is to use the fault handlers only in
assembly code where we have full control. Changed that for x86 (save for the
vm86 mode, which has a similar mechanism), but not for the other
architectures.
* Introduced fault_handler, fault_handler_stack_pointer, and fault_jump_buffer
fields in the cpu_ent structure, which must be used instead of
thread::fault_handler in the kernel debugger. Consequently user_memcpy() must
not be used in the kernel debugger either. Introduced a debug_memcpy()
instead.
* Introduced debug_call_with_fault_handler() function which calls a function
in a setjmp() and fault handler context. The architecture specific backend
arch_debug_call_with_fault_handler() has only been implemented for x86 yet.
* Introduced debug_is_kernel_memory_accessible() for use in the kernel
debugger. It determines whether a range of memory can be accessed in the
way specified. The architecture specific back end
arch_vm_translation_map_is_kernel_page_accessible() has only been implemented
for x86 yet.
* Added arch_debug_unset_current_thread() (only implemented for x86) to unset
the current thread pointer in the kernel debugger. When entering the kernel
debugger we do some basic sanity checks of the currently set thread structure
and unset it, if they fail. This allows certain commands (most importantly
the stack trace command) to avoid accessing the thread structure.
* x86: When handling a double fault, we do now install a special handler for
page faults. This allows us to gracefully catch faulting commands, even if
e.g. the thread structure is toast.

We are now in much better shape to deal with double faults. Hopefully avoiding
the triple faults that some people have been experiencing on their hardware
and ideally even allowing to use the kernel debugger normally.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32073 a95241bf-73f2-0310-859d-f6bbb57e9c96

Replaced the temporary storage used in the kernel debug command parser. We now
have a simple dedicated heap for the kernel debugger with stacked allocation
pools (deleting a pool frees all memory allocated in it). The heap should
eventually be used for all commands that need temporary storage too large for
the stack instead of each using its own static buffer.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30949 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Add has_debugger_command() so whether or not a debugger command is available
can be checked.
* Make the usb_keyboard module check the presence of the needed debugger
commands to avoid the error messages in case of them being unavailable.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29472 a95241bf-73f2-0310-859d-f6bbb57e9c96

Remove separate GCC4 versions of add_debug_command()/remove_debug_command() and
add the const in any case. As Axel points out these are C functions and we do
not affect binary compatibility by changing their signature.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29124 a95241bf-73f2-0310-859d-f6bbb57e9c96

Fixing warnings under GCC4 in preparation to enable -Werror there as well:
* Replaced the use of offsetof() for structs that aren't PODs. Add a
offset_of_member() macro to util/khash.h because that's what it's used for
in our cases.
* Change the signature of add_debugger_command()/remove_debugger_command() on
GCC > 2 to avoid the depricated conversion from string constants to char *.
* Adding some "suggested" parenthesis. I know that not everyone likes that, but
it pointed out at least one bug that is fixed here as well.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29113 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Removed the DEBUG_DEBUGGER_COMMANDS define again, and followed Ingo's
suggestion by adding a "faults" command that now sets the
gInvokeCommandDirectly variable as wished.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28382 a95241bf-73f2-0310-859d-f6bbb57e9c96

* If DEBUG_DEBUGGER_COMMANDS is 1, invoke_debugger_command() will no longer
install a fault handler, allowing to debug KDL commands better.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28376 a95241bf-73f2-0310-859d-f6bbb57e9c96

bonefish + mmlr:
* Add possibility to restart a complete pipe through B_KDEBUG_RESTART_PIPE.
* Implement tail in the kernel debugger making use of the former.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28154 a95241bf-73f2-0310-859d-f6bbb57e9c96

When in the kernel debugger we do now record the relevant information
(fault address, pc, read/write) when a page fault occurs, and print them
in case this caused the termination of a debugger command.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26949 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Removed -Wno-unused from all KernelMergeObjects in kernel Jamfiles.
* Fixed most of the warnings resulting from that by removing actually not used
variables or moving declaration into the #IF. Left unused functions there
though, as I wouldn't know if they are supposed to be used again.
* Fixed two statements with no effect (clamping to MAX_ANCILLARY_DATA_LEN in
socket.cpp and unsetting fCounterSem in MessagingService.cpp).
* Some style cleanups.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26253 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added optional spinlock contention measurement feature. Enabled when
B_DEBUG_SPINLOCK_CONTENTION is defined to 1. It typedefs spinlock to a
structure (thus breaking BeOS binary compatibility), containing a
counter which is incremented whenever a thread has to wait for the
spinlock.
* Added macros for spinlock initialization and access and changed
code using spinlocks accordingly. This breaks compilation for BeOS --
the macros should be defined in the respective compatibility wrappers.
* Added generic syscall to get the spinlock counters for the thread and
the team spinlocks.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25752 a95241bf-73f2-0310-859d-f6bbb57e9c96

Enforce 80 columns maximum line length.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25746 a95241bf-73f2-0310-859d-f6bbb57e9c96

gcc4 build fix.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25745 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Introduced pipes in the kernel debugger. The syntax is similar to
pipes in the shell, though the semantics is a little different: The
second command is invoked whenever the first command has written a
complete line. The line is passed as last argument to the second
command. The new command flag B_KDEBUG_PIPE_FINAL_RERUN causes the
second command to be invoked again (with NULL argument) after the
first command is done.
* Added kprintf_unfiltered() and kputs_unfiltered() which bypass the
pipe mechanism and directly print to the bluescreen/serial output.
* Moved most commands from debug.cpp to the new
debug_builtin_commands.cpp.
* B_KDEBUG_DONT_PARSE_ARGUMENTS commands don't get an argument anymore,
if it would consist of white space only.
* Added new debugger command return value B_KDEBUG_ERROR, which
indicates that executing the command failed. This return code will
abort a complete pipe.
* Since debugger commands can nest (i.e. one command can invoke another
one) the setjmp()/longjmp() mechanism to restore the stack after a
page fault in a command needs more than one jump buffer.
* Added abort_debugger_command(), which longjmp()s out of the currently
executed command. This will also abort the current pipe.
* When pagination is enabled pressing "a" will abort the running command
(as opposed to "q" which only disables the blue screen output, but
lets the command continue).
* Added debugger commands:
- "grep" which can be used to filter output by pattern. Removed the
"filter" command and the underlying mechanism that did that before.
- "head" which prints only the first lines of output of another
command.
- "wc" counts lines, words, and characters of another command's
output.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25744 a95241bf-73f2-0310-859d-f6bbb57e9c96

Made kputs() available in the kernel and used it for printing debugger
command usage texts, which can be too long for kprintf().


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23677 a95241bf-73f2-0310-859d-f6bbb57e9c96

The usage string directly printed by print_debugger_command() and
invoke_debugger_command() is now automatically preceded by
"usage: <command name>", so the string passed to
add_debugger_command_etc() shouldn't contain it anymore.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23584 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added add_debugger_command_etc() which is similar to
add_debugger_command(), but additionally takes parameters "usage"
and "flags".
* Added add_debugger_command_alias() which creates another name for an
existing command.
* Added print_debugger_command_usage() to print a command's usage.
* invoke_debugger_command() intercepts invocations with "--help" and
prints the command's usage text, if it is known. If unknown, the
command will be called normally.
* Made use of the new functions in debug.cpp.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23573 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Changed the way temporary variables work. They won't be unset before
a command is executed anymore. Instead the least recently used
temporary variable is overwritten, if there's no free slot for a new
temporary variable.
* Removed the special handling for the command result variable ("_"). It
just works like any other temporary variable, now.
* Individual temporary variables can be removed (e.g. using the "unset"
command).
* Added unset_all_debug_variables() and "unset_all" command to unset
all persistent and temporary variables.
* Removed remove_all_temporary_debug_variables and renamed
remove_debug_variable() to unset_debug_variable().


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23568 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Based on ahwayakchih's blue screen paging code (see bug #1444), I added
paging support to KDL (but not the on-screen debug output for now).
* Defaults to "on", use the new "paging" KDL command to turn it off (or on
again).
* When pressing 'q' while it is waiting for a key, it will now eat the rest
of the commands output (helpful for slow screen output of a large data set).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23566 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Implemented parse_expression(). The back-end is an expression parser
that is a little more powerful than BeOS'. It features:
- Persistent and temporary uint64 variables. The former kind is set
only by the user. The latter (those prefixed "_") can be set
automatically by commands, thus e.g. making it easier to access
members of a dumped structure. They are unset when the next command
is invoked. The special temporary variable "_" is defined as a
command's return value.
- Expressions can contain nested command invocations using brackets
("[ ... ]").
- Command lines are parsed by the expression parser, too. They can
contain command invocations (in brackets) and expressions (in
parentheses).
* Added debugger commands:
- expr: Evaluates the given expression and prints the result.
- unset: Undefines a variable.
- vars: Prints the values of all defined variables.
* Moved debugger command code into its own source file.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23546 a95241bf-73f2-0310-859d-f6bbb57e9c96

Change instances of wether in comments to whether. No functional change intended.

Check if the name is already used in add_debugger_command*() and reject
duplicate attempt(s).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@40611 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Fixed the semantics of [v]snprintf(): If the buffer is not large enough,
the function shall nevertheless return the length of the string that would
be written, if the buffer were large enough.
Added a touch of C++ while doing that. :-)
* Fixed the instances in boot loader, kernel, and kernel modules where the
wrong semantics were expected. The majority of uses actually.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34826 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Renamed the ROUNDOWN macro to ROUNDDOWN. Also changed the implementation of
ROUNDUP to use '*' and '/' -- the compiler will optimize that for powers of
two anyway and this implementation works for other numbers as well.
* The thread::fault_handler use in C[++] code was broken with gcc 4. At least
when other functions were invoked. Trying to trick the compiler wasn't a
particularly good idea anyway, since the next compiler version could break
the trick again. So the general policy is to use the fault handlers only in
assembly code where we have full control. Changed that for x86 (save for the
vm86 mode, which has a similar mechanism), but not for the other
architectures.
* Introduced fault_handler, fault_handler_stack_pointer, and fault_jump_buffer
fields in the cpu_ent structure, which must be used instead of
thread::fault_handler in the kernel debugger. Consequently user_memcpy() must
not be used in the kernel debugger either. Introduced a debug_memcpy()
instead.
* Introduced debug_call_with_fault_handler() function which calls a function
in a setjmp() and fault handler context. The architecture specific backend
arch_debug_call_with_fault_handler() has only been implemented for x86 yet.
* Introduced debug_is_kernel_memory_accessible() for use in the kernel
debugger. It determines whether a range of memory can be accessed in the
way specified. The architecture specific back end
arch_vm_translation_map_is_kernel_page_accessible() has only been implemented
for x86 yet.
* Added arch_debug_unset_current_thread() (only implemented for x86) to unset
the current thread pointer in the kernel debugger. When entering the kernel
debugger we do some basic sanity checks of the currently set thread structure
and unset it, if they fail. This allows certain commands (most importantly
the stack trace command) to avoid accessing the thread structure.
* x86: When handling a double fault, we do now install a special handler for
page faults. This allows us to gracefully catch faulting commands, even if
e.g. the thread structure is toast.

We are now in much better shape to deal with double faults. Hopefully avoiding
the triple faults that some people have been experiencing on their hardware
and ideally even allowing to use the kernel debugger normally.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32073 a95241bf-73f2-0310-859d-f6bbb57e9c96

Replaced the temporary storage used in the kernel debug command parser. We now
have a simple dedicated heap for the kernel debugger with stacked allocation
pools (deleting a pool frees all memory allocated in it). The heap should
eventually be used for all commands that need temporary storage too large for
the stack instead of each using its own static buffer.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30949 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Add has_debugger_command() so whether or not a debugger command is available
can be checked.
* Make the usb_keyboard module check the presence of the needed debugger
commands to avoid the error messages in case of them being unavailable.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29472 a95241bf-73f2-0310-859d-f6bbb57e9c96

Remove separate GCC4 versions of add_debug_command()/remove_debug_command() and
add the const in any case. As Axel points out these are C functions and we do
not affect binary compatibility by changing their signature.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29124 a95241bf-73f2-0310-859d-f6bbb57e9c96

Fixing warnings under GCC4 in preparation to enable -Werror there as well:
* Replaced the use of offsetof() for structs that aren't PODs. Add a
offset_of_member() macro to util/khash.h because that's what it's used for
in our cases.
* Change the signature of add_debugger_command()/remove_debugger_command() on
GCC > 2 to avoid the depricated conversion from string constants to char *.
* Adding some "suggested" parenthesis. I know that not everyone likes that, but
it pointed out at least one bug that is fixed here as well.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29113 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Removed the DEBUG_DEBUGGER_COMMANDS define again, and followed Ingo's
suggestion by adding a "faults" command that now sets the
gInvokeCommandDirectly variable as wished.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28382 a95241bf-73f2-0310-859d-f6bbb57e9c96

* If DEBUG_DEBUGGER_COMMANDS is 1, invoke_debugger_command() will no longer
install a fault handler, allowing to debug KDL commands better.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28376 a95241bf-73f2-0310-859d-f6bbb57e9c96

bonefish + mmlr:
* Add possibility to restart a complete pipe through B_KDEBUG_RESTART_PIPE.
* Implement tail in the kernel debugger making use of the former.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@28154 a95241bf-73f2-0310-859d-f6bbb57e9c96

When in the kernel debugger we do now record the relevant information
(fault address, pc, read/write) when a page fault occurs, and print them
in case this caused the termination of a debugger command.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26949 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Removed -Wno-unused from all KernelMergeObjects in kernel Jamfiles.
* Fixed most of the warnings resulting from that by removing actually not used
variables or moving declaration into the #IF. Left unused functions there
though, as I wouldn't know if they are supposed to be used again.
* Fixed two statements with no effect (clamping to MAX_ANCILLARY_DATA_LEN in
socket.cpp and unsetting fCounterSem in MessagingService.cpp).
* Some style cleanups.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26253 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added optional spinlock contention measurement feature. Enabled when
B_DEBUG_SPINLOCK_CONTENTION is defined to 1. It typedefs spinlock to a
structure (thus breaking BeOS binary compatibility), containing a
counter which is incremented whenever a thread has to wait for the
spinlock.
* Added macros for spinlock initialization and access and changed
code using spinlocks accordingly. This breaks compilation for BeOS --
the macros should be defined in the respective compatibility wrappers.
* Added generic syscall to get the spinlock counters for the thread and
the team spinlocks.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25752 a95241bf-73f2-0310-859d-f6bbb57e9c96

Enforce 80 columns maximum line length.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25746 a95241bf-73f2-0310-859d-f6bbb57e9c96

gcc4 build fix.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25745 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Introduced pipes in the kernel debugger. The syntax is similar to
pipes in the shell, though the semantics is a little different: The
second command is invoked whenever the first command has written a
complete line. The line is passed as last argument to the second
command. The new command flag B_KDEBUG_PIPE_FINAL_RERUN causes the
second command to be invoked again (with NULL argument) after the
first command is done.
* Added kprintf_unfiltered() and kputs_unfiltered() which bypass the
pipe mechanism and directly print to the bluescreen/serial output.
* Moved most commands from debug.cpp to the new
debug_builtin_commands.cpp.
* B_KDEBUG_DONT_PARSE_ARGUMENTS commands don't get an argument anymore,
if it would consist of white space only.
* Added new debugger command return value B_KDEBUG_ERROR, which
indicates that executing the command failed. This return code will
abort a complete pipe.
* Since debugger commands can nest (i.e. one command can invoke another
one) the setjmp()/longjmp() mechanism to restore the stack after a
page fault in a command needs more than one jump buffer.
* Added abort_debugger_command(), which longjmp()s out of the currently
executed command. This will also abort the current pipe.
* When pagination is enabled pressing "a" will abort the running command
(as opposed to "q" which only disables the blue screen output, but
lets the command continue).
* Added debugger commands:
- "grep" which can be used to filter output by pattern. Removed the
"filter" command and the underlying mechanism that did that before.
- "head" which prints only the first lines of output of another
command.
- "wc" counts lines, words, and characters of another command's
output.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25744 a95241bf-73f2-0310-859d-f6bbb57e9c96

Made kputs() available in the kernel and used it for printing debugger
command usage texts, which can be too long for kprintf().


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23677 a95241bf-73f2-0310-859d-f6bbb57e9c96

The usage string directly printed by print_debugger_command() and
invoke_debugger_command() is now automatically preceded by
"usage: <command name>", so the string passed to
add_debugger_command_etc() shouldn't contain it anymore.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23584 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added add_debugger_command_etc() which is similar to
add_debugger_command(), but additionally takes parameters "usage"
and "flags".
* Added add_debugger_command_alias() which creates another name for an
existing command.
* Added print_debugger_command_usage() to print a command's usage.
* invoke_debugger_command() intercepts invocations with "--help" and
prints the command's usage text, if it is known. If unknown, the
command will be called normally.
* Made use of the new functions in debug.cpp.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23573 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Changed the way temporary variables work. They won't be unset before
a command is executed anymore. Instead the least recently used
temporary variable is overwritten, if there's no free slot for a new
temporary variable.
* Removed the special handling for the command result variable ("_"). It
just works like any other temporary variable, now.
* Individual temporary variables can be removed (e.g. using the "unset"
command).
* Added unset_all_debug_variables() and "unset_all" command to unset
all persistent and temporary variables.
* Removed remove_all_temporary_debug_variables and renamed
remove_debug_variable() to unset_debug_variable().


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23568 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Based on ahwayakchih's blue screen paging code (see bug #1444), I added
paging support to KDL (but not the on-screen debug output for now).
* Defaults to "on", use the new "paging" KDL command to turn it off (or on
again).
* When pressing 'q' while it is waiting for a key, it will now eat the rest
of the commands output (helpful for slow screen output of a large data set).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23566 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Implemented parse_expression(). The back-end is an expression parser
that is a little more powerful than BeOS'. It features:
- Persistent and temporary uint64 variables. The former kind is set
only by the user. The latter (those prefixed "_") can be set
automatically by commands, thus e.g. making it easier to access
members of a dumped structure. They are unset when the next command
is invoked. The special temporary variable "_" is defined as a
command's return value.
- Expressions can contain nested command invocations using brackets
("[ ... ]").
- Command lines are parsed by the expression parser, too. They can
contain command invocations (in brackets) and expressions (in
parentheses).
* Added debugger commands:
- expr: Evaluates the given expression and prints the result.
- unset: Undefines a variable.
- vars: Prints the values of all defined variables.
* Moved debugger command code into its own source file.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23546 a95241bf-73f2-0310-859d-f6bbb57e9c96