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* dyndbg: refine verbosity 1-4 summary-detailJim Cromie2021-10-211-11/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | adjust current v*pr_info() calls to fit an overview..detail scheme: 1- module level activity: add/remove, etc 2- command ingest, splitting, summary of effects. per >control write 3- command parsing: op, flags, search terms 4- per-site change msg can yield ~3k x 2 logs per echo "+p;-p" > command. Summarize these 4 levels in MODULE_PARM_DESC, and update verbose=3 in Doc. 2- is new, to isolate a problem where a stress-test script (which feeds ~4kb multi-command strings) would produce short writes, truncating last command and causing parsing errors, which confused test results. The script fix was to use syswrite, to deliver full proper commands. 4- gets per-callsite "changed:" pr-infos, which are very noisy during stress tests, and formerly obscured v1-3 messages, and overwhelmed the static-key workload being tested. The verbose parameter has previously seen adjustment: commit 481c0e33f1e7 ("dyndbg: refine debug verbosity; 1 is basic, 2 more chatty") The script driving these adjustments is: !/usr/bin/perl -w =for Doc 1st purpose was to benchmark the effect of wildcard queries on query performance; if wildcards are risk free cheap enough, we can deploy them in the (floating) format search. 1st finding: wildcards take 2x as long to process. 2nd purpose was to benchmark real static-key changes VS simple flag changes. Found ~100x decrease for the hard work. The script maximizes workload per >control by packing it a ~4kb string of "+p; -p;" commands; this uncovered some broken stuff. The 85th query failed, and appears to be truncated, so is gramatically incorrect. Its either an error here, or in the kernel. Its not happening atm, retest. Plot thickens: fail only happens doing +-p, not +-mf, likely load dependent. Error remains consistent. Looks like a short write, longer on writer than kernel-reader. Try syswrite on handle to control this. That fixed short write. =cut use Getopt::Std; getopts('vN:k:', \my %opts) or die <<EOH; $0 options: -v verbose -k=n kernel dyndbg verbosity -N=n number of loops.. tbrc EOH $opts{N} //= 10; # !undef, 0 tests too long. my $ctrl = '/proc/dynamic_debug/control'; vx($opts{k}) if defined $opts{k}; # works on -k0 open(my $CTL, '>', $ctrl) or die "cant open $ctrl for writing: $!\n"; sub vx { my $arg = shift; my $cmd = "echo $arg > /sys/module/dynamic_debug/parameters/verbose"; system($cmd); warn("vx problem: rc:$? err:$! qry: $cmd\n") if ($?); } sub qryOK { my $qry = shift; print "syntax test: <\n$qry>\n" if $opts{v}; my $bytes = syswrite $CTL, $qry; printf "short read: $bytes / %d\n", length $qry if $bytes < length $qry; if ($?) { warn "rc:$? err:$! qry: $qry\n"; return 0; } return 1; } sub build_queries { my ($cmd, $flags, $ct) = @_; # build experiment and reference queries my $cycle = " $cmd +$flags # on ; $cmd -$flags # off \n"; my $ref = " +$flags ; -$flags \n"; my $len = length $cycle; my $max = int(4096 / $len); # break/fit to buffer size $ct |= $max; print "qry: ct:$max x << \n$cycle >>\n"; return unless qryOK($ref); return unless qryOK($cycle); my $wild = $cycle x $ct; my $empty = $ref x $ct; printf "len: %d, %d\n", length $wild, length $empty; return { trial => $wild, ref => $empty, probe => $cycle, zero => $ref, count => $ct, max => $max }; } my $query_set = build_queries(' file "*" module "*" func "*" ', "mf"); qryOK($query_set->{zero}); qryOK($query_set->{probe}); qryOK($query_set->{ref}); qryOK($query_set->{trial}); use Benchmark; sub dobatch { my ($cmd, $flags, $reps, $ct) = @_; $reps ||= $opts{N}; my $qs = build_queries($cmd, $flags, $ct); timethese($reps, { wildcards => sub { syswrite $CTL, $qs->{trial}; }, no_search => sub { syswrite $CTL, $qs->{ref}; } } ); } sub bench_static_key_toggle { vx 0; dobatch(' file "*" module "*" func "*" ', "mf"); dobatch(' file "*" module "*" func "*" ', "p"); } sub bench_verbose_levels { for my $i (0..4) { vx $i; dobatch(' file "*" module "*" func "*" ', "mf"); } } bench_static_key_toggle(); __END__ Heres how the test-script runs: :: verbose=3 parsing info [ 48.401646] dyndbg: query 95: "file "*" module "*" func "*" -mf # off " mod:* [ 48.402040] dyndbg: split into words: "file" "*" "module" "*" "func" "*" "-mf" [ 48.402456] dyndbg: op='-' [ 48.402615] dyndbg: flags=0x6 [ 48.402779] dyndbg: *flagsp=0x0 *maskp=0xfffffff9 [ 48.403033] dyndbg: parsed: func="*" file="*" module="*" format="" lineno=0-0 [ 48.403674] dyndbg: applied: func="*" file="*" module="*" format="" lineno=0-0 :: verbose=2 >control summary. ~300k site matches/changes per 4kb command [ 48.404063] dyndbg: processed 96 queries, with 296160 matches, 0 errs :: 2 queries against each other, no-search vs all-wildcard-search qry: ct:48 x << file "*" module "*" func "*" +mf # on ; file "*" module "*" func "*" -mf # off >> len: 4080, 576 Benchmark: timing 10 iterations of no_search, wildcards... no_search: 0 wallclock secs ( 0.00 usr + 0.03 sys = 0.03 CPU) @ 333.33/s (n=10) (warning: too few iterations for a reliable count) wildcards: 0 wallclock secs ( 0.00 usr + 0.09 sys = 0.09 CPU) @ 111.11/s (n=10) (warning: too few iterations for a reliable count) :: 2 queries, both doing real work / changing stati-key states. qry: ct:49 x << file "*" module "*" func "*" +p # on ; file "*" module "*" func "*" -p # off >> len: 4067, 490 Benchmark: timing 10 iterations of no_search, wildcards... no_search: 20 wallclock secs ( 0.00 usr + 20.36 sys = 20.36 CPU) @ 0.49/s (n=10) wildcards: 21 wallclock secs ( 0.00 usr + 21.08 sys = 21.08 CPU) @ 0.47/s (n=10) bash-5.1# Thats 150k static-key-toggles / sec ~600x slower than simple flags on qemu --smp 3 run Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20211019210746.185307-1-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: fix spurious vNpr_info changeJim Cromie2021-10-151-1/+1
| | | | | | | | | | The cited commit inadvertently altered the verbose level of a vpr_info, restore it to original. Fixes: 216a0fc40897 ("dyndbg: show module in vpr-info in dd-exec-queries") Signed-off-By: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20211014223614.1952171-1-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: no vpr-info on empty queriesJim Cromie2021-10-141-2/+4
| | | | | | | | | | when `echo $cmd > control` contains multiple queries, extra query separators (;\n) can parse as empty statements. This is normal, and a vpr-info on an empty command is just noise. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20211013220726.1280565-4-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: vpr-info on remove-module complete, not startingJim Cromie2021-10-141-2/+2
| | | | | | | | | | On qemu --smp 3 runs, remove-module can get called 3 times. So don't print on entry; instead print "removed" after entry is found and removed, so just once. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20211013220726.1280565-3-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: Remove support for ddebug_query paramAndrew Halaney2021-10-141-25/+0
| | | | | | | | | | This param has been deprecated for a very long time now, let's rip it out. Signed-off-by: Andrew Halaney <ahalaney@redhat.com> Signed-off-by: Jason Baron <jbaron@akamai.com> Link: https://lore.kernel.org/r/1634139622-20667-3-git-send-email-jbaron@akamai.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: make dyndbg a known cli paramAndrew Halaney2021-10-141-0/+12
| | | | | | | | | | | | | | | | | | | | | Right now dyndbg shows up as an unknown parameter if used on boot: Unknown command line parameters: dyndbg=+p That's because it is unknown, it doesn't sit in the __param section, so the processing done to warn users supplying an unknown parameter doesn't think it is legitimate. Install a dummy handler to register it. dynamic debug needs to search the whole command line for modules listed that are currently builtin, so there's no real work to be done in this callback. Fixes: 86d1919a4fb0 ("init: print out unknown kernel parameters") Tested-by: Jim Cromie <jim.cromie@gmail.com> Signed-off-by: Andrew Halaney <ahalaney@redhat.com> Signed-off-by: Jason Baron <jbaron@akamai.com> Link: https://lore.kernel.org/r/1634139622-20667-2-git-send-email-jbaron@akamai.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: show module in vpr-info in dd-exec-queriesJim Cromie2021-10-131-1/+1
| | | | | | | | | | dynamic_debug_exec_queries() accepts a separate module arg (so it can support $module.dyndbg boot arg), display that in the vpr-info for a more useful user-debug context. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20211012183310.1016678-2-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* lib: fix spelling mistakesZhen Lei2021-07-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix some spelling mistakes in comments: permanentely ==> permanently wont ==> won't remaning ==> remaining succed ==> succeed shouldnt ==> shouldn't alpha-numeric ==> alphanumeric storeing ==> storing funtion ==> function documenation ==> documentation Determin ==> Determine intepreted ==> interpreted ammount ==> amount obious ==> obvious interupts ==> interrupts occured ==> occurred asssociated ==> associated taking into acount ==> taking into account squence ==> sequence stil ==> still contiguos ==> contiguous matchs ==> matches Link: https://lkml.kernel.org/r/20210607072555.12416-1-thunder.leizhen@huawei.com Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dyndbg: display KiB of data memory used.Jim Cromie2021-05-271-3/+3
| | | | | | | | | | | If booted with verbose>=1, dyndbg prints the memory usage in bytes, of builtin modules' prdebugs. KiB reads better. no functional changes. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20210525033240.35260-1-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: drop uninformative vpr_infoJim Cromie2021-05-131-1/+0
| | | | | | | | | | | Remove a vpr_info which I added in 2012, when I knew even less than now. In 2020, a simpler pr_fmt stripped it of context, and any remaining value. no functional change. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20210504222235.1033685-3-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: avoid calling dyndbg_emit_prefix when it has no workJim Cromie2021-05-131-7/+12
| | | | | | | | | | | | | Wrap function in a static-inline one, which checks flags to avoid calling the function unnecessarily. And hoist its output-buffer initialization to the grand-caller, which is already allocating the buffer on the stack, and can trivially initialize it too. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20210504222235.1033685-2-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: fix parsing file query without a line-range suffixShuo Chen2021-04-301-1/+1
| | | | | | | | | | | | | | | | | Query like 'file tcp_input.c line 1234 +p' was broken by commit aaebe329bff0 ("dyndbg: accept 'file foo.c:func1' and 'file foo.c:10-100'") because a file name without a ':' now makes the loop in ddebug_parse_query() exits early before parsing the 'line 1234' part. As a result, all pr_debug() in tcp_input.c will be enabled, instead of only the one on line 1234. Changing 'break' to 'continue' fixes this. Fixes: aaebe329bff0 ("dyndbg: accept 'file foo.c:func1' and 'file foo.c:10-100'") Cc: stable <stable@vger.kernel.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Shuo Chen <shuochen@google.com> Acked-by: Jason Baron <jbaron@akamai.com> Link: https://lore.kernel.org/r/20210414212400.2927281-1-giantchen@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: fix use before null checkJim Cromie2020-12-091-2/+7
| | | | | | | | | | | | | | | | In commit a2d375eda771 ("dyndbg: refine export, rename to dynamic_debug_exec_queries()"), a string is copied before checking it isn't NULL. Fix this, report a usage/interface error, and return the proper error code. Fixes: a2d375eda771 ("dyndbg: refine export, rename to dynamic_debug_exec_queries()") Cc: stable@vger.kernel.org -- -v2 drop comment tweak, improve commit message Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20201209183625.2432329-1-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: use keyword, arg varnames for query term pairsJim Cromie2020-09-271-12/+15
| | | | | | | | | optimize for clarity by replacing word[i,i+1] refs with temps. no functional changes. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200921190433.1149521-3-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Revert "dyndbg: accept query terms like file=bar and module=foo"Greg Kroah-Hartman2020-09-101-33/+20
| | | | | | | | | | | | | | | This reverts commit 14775b04964264189caa4a0862eac05dab8c0502 as there were still some parsing problems with it, and the follow-on patch for it. Let's revisit it later, just drop it for now. Cc: <jbaron@akamai.com> Cc: Jim Cromie <jim.cromie@gmail.com> Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Fixes: 14775b049642 ("dyndbg: accept query terms like file=bar and module=foo") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Revert "dyndbg: fix problem parsing format="foo bar""Greg Kroah-Hartman2020-09-101-17/+21
| | | | | | | | | | | | This reverts commit 42f07816ac0cc797928119cc039c414ae2b95d34 as it still causes problems. It will be resolved later, let's revert it so we can also revert the original patch this was supposed to be helping with. Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Fixes: 42f07816ac0c ("dyndbg: fix problem parsing format="foo bar"") Cc: Jim Cromie <jim.cromie@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: fix problem parsing format="foo bar"Jim Cromie2020-09-041-21/+17
| | | | | | | | | | | | | | | | | | commit 14775b049642 ("dyndbg: accept query terms like file=bar and module=foo") added the combined keyword=value parsing poorly; revert most of it, keeping the keyword & arg change. Instead, fix the tokenizer for the new input, by terminating the keyword (an unquoted word) on '=' as well as space, thus letting the tokenizer work on the quoted argument, like it would have previously. Also add a few debug-prints to show more parsing context, into tokenizer and parse-query, and use "keyword, value" in others. Fixes: 14775b049642 ("dyndbg: accept query terms like file=bar and module=foo") Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200831182210.850852-4-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: refine export, rename to dynamic_debug_exec_queries()Jim Cromie2020-09-041-2/+25
| | | | | | | | | | | | | | | | | | | | | | commit 4c0d77828d4f ("dyndbg: export ddebug_exec_queries") had a few problems: - broken non DYNAMIC_DEBUG_CORE configs, sparse warning - the exported function modifies query string, breaks on RO strings. - func name follows internal convention, shouldn't be exposed as is. 1st is fixed in header with ifdefd function prototype or stub defn. Also remove an obsolete HAVE-symbol ifdef-comment, and add others. Fix others by wrapping existing internal function with a new one, named in accordance with module-prefix naming convention, before export hits v5.9.0. In new function, copy query string to a local buffer, so users can pass hard-coded/RO queries, and internal function can be used unchanged. Fixes: 4c0d77828d4f ("dyndbg: export ddebug_exec_queries") Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200831182210.850852-3-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: give %3u width in pr-format, cosmetic onlyJim Cromie2020-09-041-1/+1
| | | | | | | | | | Specify the print-width so log entries line up nicely. no functional changes. Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200831182210.850852-2-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: export ddebug_exec_queriesJim Cromie2020-07-241-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Export ddebug_exec_queries() for use by modules. This will allow module authors to control all their *pr_debug*s dynamically. And since ddebug_exec_queries() is what implements "echo $query >control", it gives the same per-callsite control. Virtues of this: - simplicity. just an export. - full control over any/all subsets of callsites. - same "query/command-string" in code and console - full callsite selectivity with module file line format Format in particular deserves special attention; it is where low-hanging fruit will be found. Consider: drivers/gpu/drm/amd/display/include/logger_types.h: #define DC_LOG_SURFACE(...) pr_debug("[SURFACE]:"__VA_ARGS__) #define DC_LOG_HW_LINK_TRAINING(...) pr_debug("[HW_LINK_TRAINING]:"__VA_ARGS__) .. 9 more .. Thats 11 string prefixes, used in 804 places in drivers/gpu/** Clearly this is a systematized classification of those callsites. And one I'd expect to see repeated often. Using ddebug_exec_queries(), authors can select on those prefixes as a unitary set, equivalent to: echo "module=MODULE_NAME format=^[SURFACE]: +p" >control Trivially, those sets can be subsected with the other query terms too, say file=foo, should the author see fit. Perhaps as important, users can modify the set of enabled callsites, presumably to aid debugging by enabling helpful debug callsites, and disabling those that just clutter the info. Authors could even alter [fmlt] flags, though I dont see a good reason why they would. Perhaps harnessed by bug-logging automation to get fuller, or more minimal bug-reports. DRM drm has both drm.debug, which defines 32 categories of drm_printk logging, and entirely separate uses of pr_debug, which are dynamic on this i915 laptop, running mainline. So I can observe and report on both. The i915 driver has 118 dyndbg callsites, with following "classifications" defined in drivers/gpu/drm/i915/gvt/** $ grep 915 /proc/dynamic_debug/control | cut -d= -f2 | cut -d: -f1,2 | sort -u _ "gvt: cmd _ "gvt: core _ "gvt: dpy _ "gvt: el _ "gvt: irq _ "gvt: mm _ "gvt: mmio _ "gvt: render _ "gvt: sched _ "%s for root hub!\012" _ "Vendor defined info completion code %u\012" This classification is entirely out-of-band for control by drm.debug, and is only available to root user at the console. But module authors can activate them with ddebug_exec_queries(sprintf("format=^%s +p")), and then decide how to expose the groups to the user for max utility. drm.debug drm.debug has 32 bit-flags, and matching enum drm_debug_category values to classify the ~2943 DRM_DEBUG*() callsites in drivers/gpu The drm.debug callback could invoke ddebug_exec_queries() with 32 different hardcoded query strings, needing only (bit) ? " +p" : " -p" added. I briefly enabled drm.debug=0xff on my i915 laptop, which yielded these unique prefixes: (dmesg | cut -c17- | cut -d\] -f1 | sort -u) [drm:drm_atomic_check_only [drm [drm:drm_atomic_get_crtc_state [drm [drm:drm_atomic_get_plane_state [drm [drm:drm_atomic_nonblocking_commit [drm [drm:drm_atomic_set_fb_for_plane [drm [drm:drm_atomic_state_default_clear [drm [drm:__drm_atomic_state_free [drm [drm:drm_atomic_state_init [drm [drm:drm_crtc_vblank_helper_get_vblank_timestamp_internal [drm [drm:drm_handle_vblank [drm [drm:drm_ioctl [drm [drm:drm_mode_addfb2 [drm [drm:drm_mode_object_get [drm [drm:drm_mode_object_put.part.0 [drm [drm:drm_update_vblank_count [drm [drm:drm_vblank_enable [drm [drm:drm_vblank_restore [drm [drm:vblank_disable_fn [drm i915 0000:00:02.0: [drm:gen9_set_dc_state [i915 i915 0000:00:02.0: [drm:intel_atomic_get_global_obj_state [i915 i915 0000:00:02.0: [drm:__intel_display_power_get_domain.part.0 [i915 i915 0000:00:02.0: [drm:__intel_display_power_put_domain [i915 i915 0000:00:02.0: [drm:intel_plane_atomic_calc_changes [i915 i915 0000:00:02.0: [drm:skl_enable_dc6 [i915 Several good format=^prefixes are apparent there, and some misses. ^[drm:drm_atomic_ # misses: [drm:__drm_atomic_state_free [drm ^[drm:drm_ioctl ^[drm:drm_mode ^[drm:drm_vblank_ # misses: [drm:drm_update_vblank_count & [drm:vblank_disable_fn Its not a perfect 1:1 single format-match per class, but the misses above can be covered with 1 & 2 additional queries, which can be concatenated together with ";" separators and submitted with 1 call. Benefits: For drm, adapting DRM_DEBUG to use dynamic-debug inside could replicate (and thereby obsolete) lots of bit-checking in current DRM_DEBUG callsites, at least with JUMP_LABEL optimized code. ddebug_exec_queries() and a handful of fixed query-strings can select and thereby control the already classified callsites. With the classes mapped to queries, the enum type and parameter can be eliminated (folded away with macro magic), at least for DYNAMIC_DEBUG & JUMP_LABEL builds. Is it safe ? ddebug_exec_queries() is currently exposed to user space in several limited ways; 1 it is called from module-load callback, where it implements the $modname.dyndbg=+p "fake" parameter provided to all modules. 2 it handles query input via >control directly IOW, it is "fully" exposed to local root user; exposing the same functionality to other kernel modules is no additional risk. The other standard issue to check is locking: dyndbg has a single mutex, taken by ddebug_change to handle >control, and by ddebug_proc_(start|stop) to span `cat control`. Queries submitted via export will typically have module specified, which dramatically cuts the scan by ddebug_change vs "module=* +p". ISTM this proposed export presents no locking problems. TLDR; It would be interesting to see how drm.dyndbg=$QUERY and drm.debug=$HEXY would interact; it might be order dependent, as if given as modprobe args or in /etc/modprobe.d/ Acked-by: <jbaron@akamai.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200719231058.1586423-19-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: shorten our logging prefix, drop __func__Jim Cromie2020-07-241-1/+1
| | | | | | | | | | | | For log-message output, reduce column space consumed by current pr_fmt by dropping __func__ and shortening "dynamic_debug" to "dyndbg". This improves readability on narrow consoles, and better matches other kernel boot info messages. Acked-by: <jbaron@akamai.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200719231058.1586423-18-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: allow anchored match on format query termJim Cromie2020-07-241-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This should work: echo module=amd* format=^[IF_TRACE]: +p >/proc/dynamic_debug/control consider drivers/gpu/drm/amd/display/include/logger_types.h: It has 11 defines like: #define DC_LOG_IF_TRACE(...) pr_debug("[IF_TRACE]:"__VA_ARGS__) These defines are used 804 times at recent count; they are a good use case to evaluate existing format-message based classifications of *pr_debug*. Those macros prefix the supplied format with a fixed string, I'd expect most existing message classification schemes to do something similar. Hence we want to be able to anchor our match to the beginning of the format string, allowing easy construction of clear and precise queries, leveraging the existing classification scheme to enable and disable those callsites. Note that unlike other search terms, formats are implicitly floating substring matches, without the need for explicit wildcards. This makes no attempt at wider regex features, just the one we need. TLDR: Using the anchor also means the []s are less helpful for disamiguating the prefix from a random in-message occurrence, allowing shorter prefixes. Acked-by: <jbaron@akamai.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200719231058.1586423-17-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: combine flags & mask into a struct, simplify with itJim Cromie2020-07-241-21/+24
| | | | | | | | | | | | | | | | | | | | | | | | | flags & mask are used together everywhere, and are passed around together between multiple functions; they belong together in a struct, call that struct flag_settings. Use struct flag_settings to rework 3 functions: - ddebug_exec_query - declares query and flag-settings, calls other 2, passing flags - ddebug_parse_flags - fills flag_settings and returns - ddebug_change - test all callsites against query, modify passing sites. benefits: - bit-banging always needs flags & mask, best together. - simpler function signatures - 1 less parameter, less stack overhead no functional changes Acked-by: <jbaron@akamai.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200719231058.1586423-16-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: accept query terms like file=bar and module=fooJim Cromie2020-07-241-20/+33
| | | | | | | | | | | | Current code expects "keyword" "arg" as 2 words, space separated. Change to also accept "keyword=arg" form as well, and drop !(nwords%2) requirement. Then in rest of function, use new keyword, arg variables instead of word[i], word[i+1] Acked-by: <jbaron@akamai.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200719231058.1586423-15-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: accept 'file foo.c:func1' and 'file foo.c:10-100'Jim Cromie2020-07-241-1/+17
| | | | | | | | | | | | | | | | | | | | | | Accept these additional query forms: echo "file $filestr +_" > control path/to/file.c:100 # as from control, column 1 path/to/file.c:1-100 # or any legal line-range path/to/file.c:func_A # as from an editor/browser path/to/file.c:drm_* # wildcards still work path/to/file.c:*_foo # lead wildcard too 1st 2 examples are treated as line-ranges, 3-5 are treated as func's Doc these changes, and sprinkle in a few extra wild-card examples and trailing # explanation texts. Acked-by: <jbaron@akamai.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200719231058.1586423-14-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: refactor parse_linerange out of ddebug_parse_queryJim Cromie2020-07-241-27/+36
| | | | | | | | | | | | Make the code-block reusable to later handle "file foo.c:101-200" etc. This is a 99% code move, with reindent, function wrap&call, +pr_debug. no functional changes. Acked-by: <jbaron@akamai.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200719231058.1586423-13-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: use gcc ?: to reduce word countJim Cromie2020-07-241-4/+4
| | | | | | | | | reduce word count via gcc ?: extension, no actual code change. Acked-by: <jbaron@akamai.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200719231058.1586423-12-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: make ddebug_tables list LIFO for add/remove_moduleJim Cromie2020-07-241-1/+1
| | | | | | | | | | | | loadable modules are the last in on this list, and are the only modules that could be removed. ddebug_remove_module() searches from head, but ddebug_add_module() uses list_add_tail(). Change it to list_add() for a micro-optimization. Acked-by: <jbaron@akamai.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200719231058.1586423-11-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: prefer declarative init in caller, to memset in calleeJim Cromie2020-07-241-2/+1
| | | | | | | | | | | | ddebug_exec_query declares an auto var, and passes it to ddebug_parse_query, which memsets it before using it. Drop that memset, instead initialize the variable in the caller; let the compiler decide how to do it. Acked-by: <jbaron@akamai.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200719231058.1586423-10-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: fix pr_err with empty stringJim Cromie2020-07-241-1/+1
| | | | | | | | | | this pr_err attempts to print the string after the OP, but the string has been parsed and chopped up, so looks empty. Acked-by: <jbaron@akamai.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200719231058.1586423-9-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: fix a BUG_ON in ddebug_describe_flagsJim Cromie2020-07-241-12/+11
| | | | | | | | | | | | | | | | ddebug_describe_flags() currently fills a caller provided string buffer, after testing its size (also passed) in a BUG_ON. Fix this by replacing them with a known-big-enough string buffer wrapped in a struct, and passing that instead. Also simplify ddebug_describe_flags() flags parameter from a struct to a member in that struct, and hoist the member deref up to the caller. This makes the function reusable (soon) where flags are unpacked. Acked-by: <jbaron@akamai.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200719231058.1586423-8-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: fix overcounting of ram used by dyndbgJim Cromie2020-07-241-6/+2
| | | | | | | | | | | | | | | | | | | | | | | | during dyndbg init, verbose logging prints its ram overhead. It counted strlens of struct _ddebug's 4 string members, in all callsite entries, which would be approximately correct if each had been mallocd. But they are pointers into shared .rodata; for example, all 10 kobject callsites have identical filename, module values. Its best not to count that memory at all, since we cannot know they were linked in because of CONFIG_DYNAMIC_DEBUG=y, and we want to report a number that reflects what ram is saved by deconfiguring it. Also fix wording and size under-reporting of the __dyndbg section. Heres my overhead, on a virtme-run VM on a fedora-31 laptop: dynamic_debug:dynamic_debug_init: 260 modules, 2479 entries \ and 10400 bytes in ddebug tables, 138824 bytes in __dyndbg section Acked-by: <jbaron@akamai.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200719231058.1586423-7-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: rename __verbose section to __dyndbgJim Cromie2020-07-241-6/+6
| | | | | | | | | | | | | | | dyndbg populates its callsite info into __verbose section, change that to a more specific and descriptive name, __dyndbg. Also, per checkpatch: simplify __attribute(..) to __section(__dyndbg) declaration. and 1 spelling fix, decriptor Acked-by: <jbaron@akamai.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200719231058.1586423-6-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: refine debug verbosity; 1 is basic, 2 more chattyJim Cromie2020-07-241-13/+8
| | | | | | | | | | | | | | | | | | | | | | | | | The verbose/debug logging done for `cat $MNT/dynamic_debug/control` is voluminous (2 per control file entry + 2 per PAGE). Moreover, it just prints pointer and sequence, which is not useful to a dyndbg user. So just drop them. Also require verbose>=2 for several other debug printks that are a bit too chatty for typical needs; ddebug_change() prints changes, once per modified callsite. Since queries like "+p" will enable ~2300 callsites in a typical laptop, a user probably doesn't need to see them often. ddebug_exec_queries() still summarizes with verbose=1. ddebug_(add|remove)_module() also print 1 line per action on a module, not needed by typical modprobe user. This leaves verbose=1 better focussed on the >control parsing process. Acked-by: <jbaron@akamai.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200719231058.1586423-5-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dyndbg: drop obsolete comment on ddebug_proc_openJim Cromie2020-07-241-7/+0
| | | | | | | | | | | | | commit 4bad78c55002 ("lib/dynamic_debug.c: use seq_open_private() instead of seq_open()")' The commit was one of a tree-wide set which replaced open-coded boilerplate with a single tail-call. It therefore obsoleted the comment about that boilerplate, clean that up now. Acked-by: <jbaron@akamai.com> Signed-off-by: Jim Cromie <jim.cromie@gmail.com> Link: https://lore.kernel.org/r/20200719231058.1586423-4-jim.cromie@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* dynamic_debug: add an option to enable dynamic debug for modules onlyOrson Zhai2020-06-081-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | Instead of enabling dynamic debug globally with CONFIG_DYNAMIC_DEBUG, CONFIG_DYNAMIC_DEBUG_CORE will only enable core function of dynamic debug. With the DYNAMIC_DEBUG_MODULE defined for any modules, dynamic debug will be tied to them. This is useful for people who only want to enable dynamic debug for kernel modules without worrying about kernel image size and memory consumption is increasing too much. [orson.zhai@unisoc.com: v2] Link: http://lkml.kernel.org/r/1587408228-10861-1-git-send-email-orson.unisoc@gmail.com Signed-off-by: Orson Zhai <orson.zhai@unisoc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Petr Mladek <pmladek@suse.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Jason Baron <jbaron@akamai.com> Cc: Randy Dunlap <rdunlap@infradead.org> Link: http://lkml.kernel.org/r/1586521984-5890-1-git-send-email-orson.unisoc@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* lib/dynamic_debug.c: use address-of operator on section symbolsNathan Chancellor2020-04-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | Clang warns: ../lib/dynamic_debug.c:1034:24: warning: array comparison always evaluates to false [-Wtautological-compare] if (__start___verbose == __stop___verbose) { ^ 1 warning generated. These are not true arrays, they are linker defined symbols, which are just addresses. Using the address of operator silences the warning and does not change the resulting assembly with either clang/ld.lld or gcc/ld (tested with diff + objdump -Dr). Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Jason Baron <jbaron@akamai.com> Link: https://github.com/ClangBuiltLinux/linux/issues/894 Link: http://lkml.kernel.org/r/20200220051320.10739-1-natechancellor@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dynamic_debug: allow to work if debugfs is disabledGreg Kroah-Hartman2020-02-121-5/+23
| | | | | | | | | | | | | | | | | | | With the realization that having debugfs enabled on "production" systems is generally not a good idea, debugfs is being disabled from more and more platforms over time. However, the functionality of dynamic debugging still is needed at times, and since it relies on debugfs for its user api, having debugfs disabled also forces dynamic debug to be disabled. To get around this, also create the "control" file for dynamic_debug in procfs. This allows people turn on debugging as needed at runtime for individual driverfs and subsystems. Reported-by: many different companies Cc: Jason Baron <jbaron@akamai.com> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20200210211142.GB1373304@kroah.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* lib: dynamic_debug: no need to check return value of debugfs_create functionsGreg Kroah-Hartman2019-06-181-9/+3
| | | | | | | | | | When calling debugfs functions, there is no need to ever check the return value. The function can work or not, but the code logic should never do something different based on this. Cc: linux-kernel@vger.kernel.org Acked-by: Jason Baron <jbaron@akamai.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* RDMA/core: Introduce RDMA subsystem ibdev_* print functionsGal Pressman2019-05-011-0/+37
| | | | | | | | | | | | | | | | | | | Similarly to dev/netdev/etc printk helpers, add standard printk helpers for the RDMA subsystem. Example output: efa 0000:00:06.0 efa_0: Hello World! efa_0: Hello World! (no parent device set) (NULL ib_device): Hello World! (ibdev is NULL) Cc: Jason Baron <jbaron@akamai.com> Suggested-by: Jason Gunthorpe <jgg@ziepe.ca> Suggested-by: Leon Romanovsky <leon@kernel.org> Signed-off-by: Gal Pressman <galpress@amazon.com> Reviewed-by: Leon Romanovsky <leonro@mellanox.com> Reviewed-by: Shiraz Saleem <shiraz.saleem@intel.com> Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
* dynamic_debug: move pr_err from module.c to ddebug_add_moduleRasmus Villemoes2019-03-071-1/+3
| | | | | | | | | | | | | | | | | | | | This serves two purposes: First, we get a diagnostic if (though extremely unlikely), any of the calls of ddebug_add_module for built-in code fails, effectively disabling dynamic_debug. Second, I want to make struct _ddebug opaque, and avoid accessing any of its members outside dynamic_debug.[ch]. Link: http://lkml.kernel.org/r/20190212214150.4807-9-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Jason Baron <jbaron@akamai.com> Cc: David Sterba <dsterba@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dynamic_debug: remove unused EXPORT_SYMBOLsRasmus Villemoes2019-03-071-2/+0
| | | | | | | | | | | | | | | | | | | The only caller of ddebug_{add,remove}_module outside dynamic_debug.c is kernel/module.c, which is obviously not itself modular (though it would be an interesting exercise to make that happen...). I also fail to see how these interfaces can be used by modules, in-tree or not. Link: http://lkml.kernel.org/r/20190212214150.4807-8-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Jason Baron <jbaron@akamai.com> Cc: David Sterba <dsterba@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dynamic_debug: use pointer comparison in ddebug_remove_moduleRasmus Villemoes2019-03-071-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we store the passed-in string directly in ddebug_add_module, we can use pointer equality instead of strcmp. This is a little more efficient, but more importantly, this also makes the code somewhat more correct: Currently, if one loads and then unloads a module whose name happens to match the KBUILD_MODNAME of some built-in functionality (which need not even be modular at all), all of their dynamic debug entries vanish along with those of the actual module. For example, loading and unloading a core.ko hides all pr_debugs from drivers/base/core.c and other built-in files called core.c (incidentally, there is an in-tree module whose name is core, but I just tested this with an out-of-tree trivial one). Link: http://lkml.kernel.org/r/20190212214150.4807-7-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Jason Baron <jbaron@akamai.com> Cc: David Sterba <dsterba@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dynamic_debug: don't duplicate modname in ddebug_add_moduleRasmus Villemoes2019-03-071-8/+7
| | | | | | | | | | | | | | | | | | | | | For built-in modules, we're already reusing the passed-in string via kstrdup_const(). But for actual modules (i.e. when we're called from dynamic_debug_setup in module.c), the passed-in string (which points at the name[] array inside struct module) is also guaranteed to live at least as long as the struct ddebug_table, since free_module() calls ddebug_remove_module(). Link: http://lkml.kernel.org/r/20190212214150.4807-6-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Jason Baron <jbaron@akamai.com> Cc: David Sterba <dsterba@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Petr Mladek <pmladek@suse.com> Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* jump_label: move 'asm goto' support test to KconfigMasahiro Yamada2019-01-061-1/+1
| | | | | | | | | | | | | | | | | | | | | Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label". The jump label is controlled by HAVE_JUMP_LABEL, which is defined like this: #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) # define HAVE_JUMP_LABEL #endif We can improve this by testing 'asm goto' support in Kconfig, then make JUMP_LABEL depend on CC_HAS_ASM_GOTO. Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will match to the real kernel capability. Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
* dynamic-debug-howto: fix optional/omitted ending line number to be LARGE ↵Randy Dunlap2017-11-171-0/+4
| | | | | | | | | | | | | | | | | | instead of 0 line-range is supposed to treat "1-" as "1-endoffile", so handle the special case by setting last_lineno to UINT_MAX. Fixes this error: dynamic_debug:ddebug_parse_query: last-line:0 < 1st-line:1 dynamic_debug:ddebug_exec_query: query parse failed Link: http://lkml.kernel.org/r/10a6a101-e2be-209f-1f41-54637824788e@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Jason Baron <jbaron@akamai.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dynamic_debug: add jump label supportJason Baron2016-08-041-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Although dynamic debug is often only used for debug builds, sometimes its enabled for production builds as well. Minimize its impact by using jump labels. This reduces the text section by 7000+ bytes in the kernel image below. It does increase data, but this should only be referenced when changing the direction of the branches, and hence usually not in cache. text data bss dec hex filename 8194852 4879776 925696 14000324 d5a0c4 vmlinux.pre 8187337 4960224 925696 14073257 d6bda9 vmlinux.post Link: http://lkml.kernel.org/r/d165b465e8c89bc582d973758d40be44c33f018b.1467837322.git.jbaron@akamai.com Signed-off-by: Jason Baron <jbaron@akamai.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Joe Perches <joe@perches.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* convert a bunch of open-coded instances of memdup_user_nul()Al Viro2016-01-041-8/+3
| | | | | | | A _lot_ of ->write() instances were open-coding it; some are converted to memdup_user_nul(), a lot more remain... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* lib/dynamic_debug.c: use kstrdup_constRasmus Villemoes2015-11-061-4/+4
| | | | | | | | | | Using kstrdup_const, thus reusing .rodata when possible, saves around 2 kB of runtime memory on my laptop/.config combination. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Jason Baron <jbaron@akamai.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* module: add extra argument for parse_params() callbackLuis R. Rodriguez2015-05-201-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This adds an extra argument onto parse_params() to be used as a way to make the unused callback a bit more useful and generic by allowing the caller to pass on a data structure of its choice. An example use case is to allow us to easily make module parameters for every module which we will do next. @ parse @ identifier name, args, params, num, level_min, level_max; identifier unknown, param, val, doing; type s16; @@ extern char *parse_args(const char *name, char *args, const struct kernel_param *params, unsigned num, s16 level_min, s16 level_max, + void *arg, int (*unknown)(char *param, char *val, const char *doing + , void *arg )); @ parse_mod @ identifier name, args, params, num, level_min, level_max; identifier unknown, param, val, doing; type s16; @@ char *parse_args(const char *name, char *args, const struct kernel_param *params, unsigned num, s16 level_min, s16 level_max, + void *arg, int (*unknown)(char *param, char *val, const char *doing + , void *arg )) { ... } @ parse_args_found @ expression R, E1, E2, E3, E4, E5, E6; identifier func; @@ ( R = parse_args(E1, E2, E3, E4, E5, E6, + NULL, func); | R = parse_args(E1, E2, E3, E4, E5, E6, + NULL, &func); | R = parse_args(E1, E2, E3, E4, E5, E6, + NULL, NULL); | parse_args(E1, E2, E3, E4, E5, E6, + NULL, func); | parse_args(E1, E2, E3, E4, E5, E6, + NULL, &func); | parse_args(E1, E2, E3, E4, E5, E6, + NULL, NULL); ) @ parse_args_unused depends on parse_args_found @ identifier parse_args_found.func; @@ int func(char *param, char *val, const char *unused + , void *arg ) { ... } @ mod_unused depends on parse_args_found @ identifier parse_args_found.func; expression A1, A2, A3; @@ - func(A1, A2, A3); + func(A1, A2, A3, NULL); Generated-by: Coccinelle SmPL Cc: cocci@systeme.lip6.fr Cc: Tejun Heo <tj@kernel.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Christoph Hellwig <hch@infradead.org> Cc: Felipe Contreras <felipe.contreras@gmail.com> Cc: Ewan Milne <emilne@redhat.com> Cc: Jean Delvare <jdelvare@suse.de> Cc: Hannes Reinecke <hare@suse.de> Cc: Jani Nikula <jani.nikula@intel.com> Cc: linux-kernel@vger.kernel.org Reviewed-by: Tejun Heo <tj@kernel.org> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
generated by cgit v1.2.3 (git 2.25.1) at 2024-12-01 03:55:02 +0000