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Oops, the last minute reduction in the clobber list for i386 MCOUNT_OVERHEAD() in r334522 was too agressive. Only mcount exit preserves %eax and %edx.
Fix high resolution kernel profiling just enough to not crash at boot time, especially for SMP. If configured, it turns itself on at boot time for calibration, so is fragile even if never otherwise used. Both types of kernel profiling were supposed to use a global spinlock in the SMP case. If hi-res profiling is configured (but not necessarily used), this was supposed to be optimized by only using it when necessary, and slightly more efficiently, in asm. But it was not done at all for mcount entry where it is necessary. This caused crashes in the SMP case when either type of profiling was enabled. For mcount exit, it only caused wrong times. The times were wrongest with an i8254 timer since using that requires exclusive access to the hardware. The i8254 timer was too slow to use here 20 years ago and is much less usable now, but it is the default for the SMP case since TSCs weren't invariant when SMP was new. Do the locking in all hi-res SMP cases for simplicity. Calibration uses special asms, and the clobber lists in these were sort of inverted. They contained the arg and return registers which are not clobbered, but on amd64 they didn't contain the residue of the call-used registers which may be clobbered (%r10 and %r11). This usually caused hangs at boot time. This usually affected even the UP case.
Fix recent breakages of kernel profiling, mostly on i386 (high resolution kernel profiling remains broken). memmove() was broken using ALTENTRY(). ALTENTRY() is only different from ENTRY() in the profiling case, and its use in that case was sort of backwards. The backwardness magically turned memmove() into memcpy() instead of completely breaking it. Only the high resolution parts of profiling itself were broken. Use ordinary ENTRY() for memmove(). Turn bcopy() into a tail call to memmove() to reduce complications. This gives slightly different pessimizations and profiling lossage. The pessimizations are minimized by not using a frame pointer() for bcopy(). Calls to profiling functions from exception trampolines were not relocated. This caused crashes on the first exception. Fix this using function pointers. Addresses of exception handlers in trampolines were not relocated. This caused unknown offsets in the profiling data. Relocate by abusing setidt_disp as for pmc although this is slower than necessary and requires namespace pollution. pmc seems to be missing some relocations. Stack traces and lots of other things in debuggers need similar relocations. Most user addresses were misclassified as unknown kernel addresses and then ignored. Treat all unknown addresses as user. Now only user addresses in the kernel text range are significantly misclassified (as known kernel addresses). The ibrs functions didn't preserve enough registers. This is the only recent breakage on amd64. Although these functions are written in asm, in the profiling case they call profiling functions which are mostly for the C ABI, so they only have to save call-used registers. They also have to save arg and return registers in some cases and actually save them in all cases to reduce complications. They end up saving all registers except %ecx on i386 and %r10 and %r11 on amd64. Saving these is only needed for 1 caller on each of amd64 and i386. Save them there. This is slightly simpler. Remove saving %ecx in handle_ibrs_exit on i386. Both handle_ibrs_entry and handle_ibrs_exit use %ecx, but only the latter needed to or did save it. But saving it there doesn't work for the profiling case. amd64 has more automatic saving of the most common scratch registers %rax, %rcx and %rdx (its complications for %r10 are from unusual use of %r10 by SYSCALL). Thus profiling of handle_ibrs_exit_rs() was not broken, and I didn't simplify the saving by moving the saving of these registers from it to the caller.
Remove lint support from system headers and MD x86 headers. Reviewed by: dim, jhb Discussed with: imp Sponsored by: The FreeBSD Foundation Differential revision: https://reviews.freebsd.org/D13156
sys: further adoption of SPDX licensing ID tags. Mainly focus on files that use BSD 3-Clause license. The Software Package Data Exchange (SPDX) group provides a specification to make it easier for automated tools to detect and summarize well known opensource licenses. We are gradually adopting the specification, noting that the tags are considered only advisory and do not, in any way, superceed or replace the license texts. Special thanks to Wind River for providing access to "The Duke of Highlander" tool: an older (2014) run over FreeBSD tree was useful as a starting point.
Renumber copyright clause 4 Renumber cluase 4 to 3, per what everybody else did when BSD granted them permission to remove clause 3. My insistance on keeping the same numbering for legal reasons is too pedantic, so give up on that point. Submitted by: Jan Schaumann <jschauma@stevens.edu> Pull Request: https://github.com/freebsd/freebsd/pull/96
Use intr_disable() and intr_restore() instead of frobbing the flags register directly to disable interrupts. Reviewed by: bde (earlier version) MFC after: 2 weeks
Unbreak cc -pg support on i386. In gcc 4.2, %ecx is used as the arg pointer when stack realignment is turned on (it is ALWAYS on for main), however in a profiling build %ecx would be clobbered by mcount(), this would lead to a segmentation fault when the code tries to reference any argument. This fix changes mcount() to preserve %ecx. PR: bin/119709 Reviewed by: bde MFC after: 1 week
i386/include/profile.h:
Fixed a syntax error for the (!__KERNEL && !__GNUCLIKE_ASM) case in
rev.1.36. Apparently, this case has never been reached even by lint.
Submitted by: stefanf
{amd64,i386}/include/profile.h:
In case the above case is actually reached, break it properly by
providing null support that will fail at link time instead of a stub
that gives wrong (null) profiling at runtime.
In MCOUNT_OVERHEAD(label), actually use the `label' parameter. We were still using the global label named "profil", and this worked accidentally because all callers use the same name.
netchild's mega-patch to isolate compiler dependencies into a central place. This moves the dependency on GCC's and other compiler's features into the central sys/cdefs.h file, while the individual source files can then refer to #ifdef __COMPILER_FEATURE_FOO where they by now used to refer to #if __GNUC__ > 3.1415 && __BARC__ <= 42. By now, GCC and ICC (the Intel compiler) have been actively tested on IA32 platforms by netchild. Extension to other compilers is supposed to be possible, of course. Submitted by: netchild Reviewed by: various developers on arch@, some time ago
/* -> /*- for copyright notices, minor format tweaks as necessary
Move the kernel-specific logic to adjust frompc from MI to MD. For these two reasons: 1. On ia64 a function pointer does not hold the address of the first instruction of a functions implementation. It holds the address of a function descriptor. Hence the user(), btrap(), eintr() and bintr() prototypes are wrong for getting the actual code address. 2. The logic forces interrupt, trap and exception entry points to be layed-out contiguously. This can not be achieved on ia64 and is generally just bad programming. The MCOUNT_FROMPC_USER macro is used to set the frompc argument to some kernel address which represents any frompc that falls outside the kernel text range. The macro can expand to ~0U to bail out in that case. The MCOUNT_FROMPC_INTR macro is used to set the frompc argument to some kernel address to represent a call to a trap or interrupt handler. This to avoid that the trap or interrupt handler appear to be called from everywhere in the call graph. The macro can expand to ~0U to prevent adjusting frompc. Note that the argument is selfpc, not frompc. This commit defines the macros on all architectures equivalently to the original code in sys/libkern/mcount.c. People can take it from here... Compile-tested on: alpha, amd64, i386, ia64 and sparc64 Boot-tested on: i386
Moved i386 asms to an i386 header. The asms are for calibration of high resolution kernel profiling (options GUPROF. "U" in GUPROF stands for microseconds resolution, but the resolution is now smaller than 1 nanosecond on multi-GHz machines and the accuracy is heading towards 1 nanosecond too). Arches that support GUPROF must now provide certain macros for the calibration. GUPROF is now only supported for i386's, so the absence of the new macros for other arches doesn't break anything that wasn't already broken. amd64's have uncommitted support for GUPROF, and sparc64's have support that seems to be complete except here (there was an #error for non-i386 cases; now there are undefined macros). Changed the asms a little: - declare them as __volatile. They must not be moved, and exporting a label across asms is technically incorrect, so try harder to stop gcc moving them. - don't put the non-clobbered register "bx" in the clobber list. The clobber lists are still more conservative than necessary. - drop the non-support for gcc-1. It just gave a better error message, and this is not useful since compiling with gcc-1 would cause thousands of worse error messages. - drop the support for aout.
Fixed some style bugs (mainly misalignment of backslashes).
Moved most of the "MI" definitions and declarations from <machine/profile.h> to <sys/gmon.h>. Cleaned them up a little by not attempting to ifdef for incomplete and out of date support for GUPROF in userland, as in the sparc64 version.
Remove advertising clause from University of California Regent's license, per letter dated July 22, 1999 and email from Peter Wemm, Alan Cox and Robert Watson. Approved by: core, peter, alc, rwatson
These are changes to allow to use the Intel C/C++ compiler (lang/icc)
to build the kernel. It doesn't affect the operation if gcc.
Most of the changes are just adding __INTEL_COMPILER to #ifdef's, as
icc v8 may define __GNUC__ some parts may look strange but are
necessary.
Additional changes:
- in_cksum.[ch]:
* use a generic C version instead of the assembly version in the !gcc
case (ASM code breaks with the optimizations icc does)
-> no bad checksums with an icc compiled kernel
Help from: andre, grehan, das
Stolen from: alpha version via ppc version
The entire checksum code should IMHO be replaced with the DragonFly
version (because it isn't guaranteed future revisions of gcc will
include similar optimizations) as in:
---snip---
Revision Changes Path
1.12 +1 -0 src/sys/conf/files.i386
1.4 +142 -558 src/sys/i386/i386/in_cksum.c
1.5 +33 -69 src/sys/i386/include/in_cksum.h
1.5 +2 -0 src/sys/netinet/igmp.c
1.6 +0 -1 src/sys/netinet/in.h
1.6 +2 -0 src/sys/netinet/ip_icmp.c
1.4 +3 -4 src/contrib/ipfilter/ip_compat.h
1.3 +1 -2 src/sbin/natd/icmp.c
1.4 +0 -1 src/sbin/natd/natd.c
1.48 +1 -0 src/sys/conf/files
1.2 +0 -1 src/sys/conf/files.amd64
1.13 +0 -1 src/sys/conf/files.i386
1.5 +0 -1 src/sys/conf/files.pc98
1.7 +1 -1 src/sys/contrib/ipfilter/netinet/fil.c
1.10 +2 -3 src/sys/contrib/ipfilter/netinet/ip_compat.h
1.10 +1 -1 src/sys/contrib/ipfilter/netinet/ip_fil.c
1.7 +1 -1 src/sys/dev/netif/txp/if_txp.c
1.7 +1 -1 src/sys/net/ip_mroute/ip_mroute.c
1.7 +1 -2 src/sys/net/ipfw/ip_fw2.c
1.6 +1 -2 src/sys/netinet/igmp.c
1.4 +158 -116 src/sys/netinet/in_cksum.c
1.6 +1 -1 src/sys/netinet/ip_gre.c
1.7 +1 -2 src/sys/netinet/ip_icmp.c
1.10 +1 -1 src/sys/netinet/ip_input.c
1.10 +1 -2 src/sys/netinet/ip_output.c
1.13 +1 -2 src/sys/netinet/tcp_input.c
1.9 +1 -2 src/sys/netinet/tcp_output.c
1.10 +1 -1 src/sys/netinet/tcp_subr.c
1.10 +1 -1 src/sys/netinet/tcp_syncache.c
1.9 +1 -2 src/sys/netinet/udp_usrreq.c
1.5 +1 -2 src/sys/netinet6/ipsec.c
1.5 +1 -2 src/sys/netproto/ipsec/ipsec.c
1.5 +1 -1 src/sys/netproto/ipsec/ipsec_input.c
1.4 +1 -2 src/sys/netproto/ipsec/ipsec_output.c
and finally remove
sys/i386/i386 in_cksum.c
sys/i386/include in_cksum.h
---snip---
- endian.h:
* DTRT in C++ mode
- quad.h:
* we don't use gcc v1 anymore, remove support for it
Suggested by: bde (long ago)
- assym.h:
* avoid zero-length arrays (remove dependency on a gcc specific
feature)
This change changes the contents of the object file, but as it's
only used to generate some values for a header, and the generator
knows how to handle this, there's no impact in the gcc case.
Explained by: bde
Submitted by: Marius Strobl <marius@alchemy.franken.de>
- aicasm.c:
* minor change to teach it about the way icc spells "-nostdinc"
Not approved by: gibbs (no reply to my mail)
- bump __FreeBSD_version (lang/icc needs to know about the changes)
Incarnations of this patch survive gcc compiles since a loooong time,
I use it on my desktop. An icc compiled kernel works since Nov. 2003
(exceptions: snd_* if used as modules), it survives a build of the
entire ports collection with icc.
Parts of this commit contains suggestions or submissions from
Marius Strobl <marius@alchemy.franken.de>.
Reviewed by: -arch
Submitted by: netchild
Use ANSI C function definition for `_mcount' and remove `static' prototype from header file. Discussed with: bde, maybe one year ago
Use C99 compatable asm statements.
Fix a declaration that is actually supposed to be a macro definition. Submitted by: marius@alchemy.franken.de
Initiate deorbit burn for the i386-only a.out related support. Moves are under way to move the remnants of the a.out toolchain to ports. As the comment in src/Makefile said, this stuff is deprecated and one should not expect this to remain beyond 4.0-REL. It has already lasted WAY beyond that. Notable exceptions: gcc - I have not touched the a.out generation stuff there. ldd/ldconfig - still have some code to interface with a.out rtld. old as/ld/etc - I have not removed these yet, pending their move to ports. some includes - necessary for ldd/ldconfig for now. Tested on: i386 (extensively), alpha
Stylify (mainly line up macro EOL-continuation \'s), and add a dummy alternative for lint.
Remove __P.
Finish revs.1.23 and 1.24 so that MCOUNT_ENTER really actually compiles for SMP in the plain profiling case. It seems to work too. This error was not detected by LINT because LINT only compiles the GUPROF profiling case, which is is a superset of the plain profiling case for !SMP but which is so broken for SMP that the buggy code is not compiled.
Add kmupetext(), a function that expands the range of memory covered by the profiler on a running system. This is not done sparsely, as memory is cheaper than processor speed and each gprof mcount() and mexitcount() operation is already very expensive. Obtained from: NAI Labs CBOSS project Funded by: DARPA
Fix MCOUNT_ENTER() so it actually compiles in the profiling case. Pointy hat to: me Submitted by: Danny J. Zerkel <dzerkel@columbus.rr.com>
Get kernel profiling on SMP systems closer to working by replacing the mcount spin mutex with a very simple non-recursive spinlock implemented using atomic operations.
Change and clean the mutex lock interface.
mtx_enter(lock, type) becomes:
mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)
similarily, for releasing a lock, we now have:
mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.
The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.
Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:
MTX_QUIET and MTX_NOSWITCH
The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:
mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.
Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.
Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.
Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.
Finally, caught up to the interface changes in all sys code.
Contributors: jake, jhb, jasone (in no particular order)
Convert all simplelocks to mutexes and remove the simplelock implementations.
Change #ifdef KERNEL to #ifdef _KERNEL in the public headers. "KERNEL" is an application space macro and the applications are supposed to be free to use it as they please (but cannot). This is consistant with the other BSD's who made this change quite some time ago. More commits to come.
$Id$ -> $FreeBSD$
Make profiling work for ELF. gprof now autodetects the format of the executable file, so it will work for both a.out and ELF format files. I have split the object format specific code into separate source files. It's cleaner than it was before, but it's still pretty crufty. Don't cheat on your make world for this update. A lot of things have to be rebuilt for it to work, including the compiler and all of the profiled libraries.
Changed to the C9x draft spelling of the (unsigned) integral type suitable for holding object pointers (ptrint_t -> uintptr_t). Added corresponding signed type (intptr_t). Changed/added corresponding non-C9x types for function pointers to match. Don't use nonstandard types to implement these types, and don't comment on them in <machine/types.h>.
Oops, fptrint_t still needs to be declared in <machine/profile.h> in the !KERNEL case. The kludge to get it declared in libc/gmon/mcount.c wasn't sufficient because fptrint_t is used in <sys/gmon.h>.
Added a kernel-only typedef (ptrint_t) giving an integral type that is least unsuitable for holding an object pointer. This should have been used to fix warnings about casts between pointers and ints on alphas. Moved corresponding existing general typedef (fptrint_t) for function pointers from the i386 <machine/profile.h> to a kernel-only typedef in <machine/types.h>. Kludged libc/gmon/mcount.c so that it can still see this typedef.
Ifdefed use of a GNU feature.
Add support for low resolution SMP kernel profiling.
- A nonprofiling version of s_lock (called s_lock_np) is used
by mcount.
- When profiling is active, more registers are clobbered in
seemingly simple assembly routines. This means that some
callers needed to save/restore extra registers.
- The stack pointer must have space for a 'fake' return address
in idle, to avoid stack underflow.
Another round of lock pushdown. Add a simplelock to deal with disable_intr()/enable_intr() as used in UP kernel. UP kernel expects that this is enough to guarantee exclusive access to regions of code bracketed by these 2 functions. Add a simplelock to bracket clock accesses in clock.c: clock_lock. Help from: Bruce Evans <bde@zeta.org.au>
Back out part 1 of the MCFH that changed $Id$ to $FreeBSD$. We are not ready for it yet.
Moved definition of FUNCTION_ALIGNMENT to a machine-dependent place. Changed it from 4 to 16 for i386's. It can be anything for i386's, but compiler options limit it to a power of 2, and assembler and linker deficiencies limit it to a small power of 2 (<= 16). We use 16 in the kernel to get smaller tables (see Makefile.i386 and <machine/asmacros.h>). We still use the default of 4 in user mode. Use HISTCOUNTER instead of (*kcount) in the definition of KCOUNT() for consistency with other macros.
Make the long-awaited change from $Id$ to $FreeBSD$ This will make a number of things easier in the future, as well as (finally!) avoiding the Id-smashing problem which has plagued developers for so long. Boy, I'm glad we're not using sup anymore. This update would have been insane otherwise.
Improved non-statistical (GUPROF) profiling: - use a more accurate and more efficient method of compensating for overheads. The old method counted too much time against leaf functions. - normally use the Pentium timestamp counter if available. On Pentiums, the times are now accurate to within a couple of cpu clock cycles per function call in the (unlikely) event that there are no cache misses in or caused by the profiling code. - optionally use an arbitrary Pentium event counter if available. - optionally regress to using the i8254 counter. - scaled the i8254 counter by a factor of 128. Now the i8254 counters overflow slightly faster than the TSC counters for a 150MHz Pentium :-) (after about 16 seconds). This is to avoid fractional overheads. files.i386: permon.c temporarily has to be classified as a profiling-routine because a couple of functions in it may be called from profiling code. options.i386: - I586_CTR_GUPROF is currently unused (oops). - I586_PMC_GUPROF should be something like 0x70000 to enable (but not use unless prof_machdep.c is changed) support for Pentium event counters. 7 is a control mode and the counter number 0 is somewhere in the 0000 bits (see perfmon.h for the encoding). profile.h: - added declarations. - cleaned up separation of user mode declarations. prof_machdep.c: Mostly clock-select changes. The default clock can be changed by editing kmem. There should be a sysctl for this. subr_prof.c: - added copyright. - calibrate overheads for the new method. - documented new method. - fixed races and and machine dependencies in start/stop code. mcount.c: Use the new overhead compensation method. gmon.h: - changed GPROF4 counter type from unsigned to int. Oops, this should be machine-dependent and/or int32_t. - reorganized overhead counters. Submitted by: Pentium event counter changes mostly by wollman
Cleaned up interrupt masking by declaring the state variable in a machine-dependent macro and passing it to all machine-dependent macros. Eliminated the state variable for the GUPROF case.
Fixed user-mode mcount which I broke in the previous revision. Do it the old way for now. Moved recent additions around a lot to minimise ifdefs. Added prototypes.
Implemented non-statistical kernel profiling. This is based on looking at a high resolution clock for each of the following events: function call, function return, interrupt entry, interrupt exit, and interesting branches. The differences between the times of these events are added at appropriate places in a ordinary histogram (as if very fast statistical profiling sampled the pc at those places) so that ordinary gprof can be used to analyze the times. gmon.h: Histogram counters need to be 4 bytes for microsecond resolutions. They will need to be larger for the 586 clock. The comments were vax-centric and wrong even on vaxes. Does anyone disagree? gprof4.c: The standard gprof should support counters of all integral sizes and the size of the counter should be in the gmon header. This hack will do until then. (Use gprof4 -u to examine the results of non-statistical profiling.) config/*: Non-statistical profiling is configured with `config -pp'. `config -p' still gives ordinary profiling. kgmon/*: Non-statistical profiling is enabled with `kgmon -B'. `kgmon -b' still enables ordinary profiling (and distables non-statistical profiling) if non-statistical profiling is configured.
Added MCOUNT_ENTER and MCOUNT_EXIT macros to profile.h Removed inb function since it's more correctly in pio.h Copied write_eflags and read_eflags over from npx.c (Some changes to the macros suggested by Bruce were not made at this time since his suggestions probably apply to all the macros and these inlined/macro definitions need a lot of cleaning up at some point in the future.) Reviewed by: Bruce
Made idempotent. Reviewed by: Submitted by:
Added $Id$
This commit was generated by cvs2svn to compensate for changes in r1543, which included commits to RCS files with non-trunk default branches.
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