linux/tools/perf/util
He Kuang bfc077b4cf perf bpf: Add prologue for BPF programs for fetching arguments
This patch generates a prologue for a BPF program which fetches arguments for
it.  With this patch, the program can have arguments as follow:

  SEC("lock_page=__lock_page page->flags")
  int lock_page(struct pt_regs *ctx, int err, unsigned long flags)
  {
 	 return 1;
  }

This patch passes at most 3 arguments from r3, r4 and r5. r1 is still the ctx
pointer. r2 is used to indicate if dereferencing was done successfully.

This patch uses r6 to hold ctx (struct pt_regs) and r7 to hold stack pointer
for result. Result of each arguments first store on stack:

 low address
 BPF_REG_FP - 24  ARG3
 BPF_REG_FP - 16  ARG2
 BPF_REG_FP - 8   ARG1
 BPF_REG_FP
 high address

Then loaded into r3, r4 and r5.

The output prologue for offn(...off2(off1(reg)))) should be:

     r6 <- r1			// save ctx into a callee saved register
     r7 <- fp
     r7 <- r7 - stack_offset	// pointer to result slot
     /* load r3 with the offset in pt_regs of 'reg' */
     (r7) <- r3			// make slot valid
     r3 <- r3 + off1		// prepare to read unsafe pointer
     r2 <- 8
     r1 <- r7			// result put onto stack
     call probe_read		// read unsafe pointer
     jnei r0, 0, err		// error checking
     r3 <- (r7)			// read result
     r3 <- r3 + off2		// prepare to read unsafe pointer
     r2 <- 8
     r1 <- r7
     call probe_read
     jnei r0, 0, err
     ...
     /* load r2, r3, r4 from stack */
     goto success
err:
     r2 <- 1
     /* load r3, r4, r5 with 0 */
     goto usercode
success:
     r2 <- 0
usercode:
     r1 <- r6	// restore ctx
     // original user code

If all of arguments reside in register (dereferencing is not
required), gen_prologue_fastpath() will be used to create
fast prologue:

     r3 <- (r1 + offset of reg1)
     r4 <- (r1 + offset of reg2)
     r5 <- (r1 + offset of reg3)
     r2 <- 0

P.S.

eBPF calling convention is defined as:

* r0		- return value from in-kernel function, and exit value
                  for eBPF program
* r1 - r5	- arguments from eBPF program to in-kernel function
* r6 - r9	- callee saved registers that in-kernel function will
                  preserve
* r10		- read-only frame pointer to access stack

Committer note:

At least testing if it builds and loads:

  # cat test_probe_arg.c
  struct pt_regs;

  __attribute__((section("lock_page=__lock_page page->flags"), used))
  int func(struct pt_regs *ctx, int err, unsigned long flags)
  {
  	return 1;
  }

  char _license[] __attribute__((section("license"), used)) = "GPL";
  int _version __attribute__((section("version"), used)) = 0x40300;
  # perf record -e ./test_probe_arg.c usleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.016 MB perf.data ]
  # perf evlist
  perf_bpf_probe:lock_page
  #

Signed-off-by: He Kuang <hekuang@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1447675815-166222-11-git-send-email-wangnan0@huawei.com
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-11-18 17:51:04 -03:00
..
include tools: Adopt memdup() from tools/perf, moving it to tools/lib/string.c 2015-11-18 17:51:02 -03:00
intel-pt-decoder perf intel-pt: Make logging slightly more efficient 2015-09-28 16:45:26 -03:00
scripting-engines perf scripting python: Allow for max_stack greater than PERF_MAX_STACK_DEPTH 2015-09-28 17:09:12 -03:00
abspath.c
alias.c perf tools: Introduce zfree 2013-12-27 15:17:00 -03:00
annotate.c perf annotate: Support full source file paths for srcline fix 2015-11-11 18:41:30 -03:00
annotate.h perf annotate: Fix sizeof_sym_hist overflow issue 2015-10-05 16:15:38 -03:00
auxtrace.c perf auxtrace: Add option to synthesize branch stacks on samples 2015-09-28 16:53:44 -03:00
auxtrace.h perf auxtrace: Add option to synthesize branch stacks on samples 2015-09-28 16:53:44 -03:00
bitmap.c
bpf-loader.c perf bpf: Add prologue for BPF programs for fetching arguments 2015-11-18 17:51:04 -03:00
bpf-loader.h perf bpf: Add prologue for BPF programs for fetching arguments 2015-11-18 17:51:04 -03:00
bpf-prologue.c perf bpf: Add prologue for BPF programs for fetching arguments 2015-11-18 17:51:04 -03:00
bpf-prologue.h perf bpf: Add prologue for BPF programs for fetching arguments 2015-11-18 17:51:04 -03:00
Build perf bpf: Add prologue for BPF programs for fetching arguments 2015-11-18 17:51:04 -03:00
build-id.c perf buildid-list: Requires ordered events 2015-11-13 12:22:04 -03:00
build-id.h perf buildid: Introduce sysfs/filename__sprintf_build_id 2015-08-28 14:53:50 -03:00
cache.h perf report: Fix some option handling on --stdio 2015-05-14 10:05:22 -03:00
callchain.c perf tools: Defaults to 'caller' callchain order only if --children is enabled 2015-10-22 15:40:11 -03:00
callchain.h perf tools: Improve call graph documents and help messages 2015-10-22 16:23:19 -03:00
cgroup.c perf cgroup: Use atomic.h for refcounting 2015-05-15 16:12:20 -03:00
cgroup.h perf cgroup: Use atomic.h for refcounting 2015-05-15 16:12:20 -03:00
cloexec.c perf bench numa: Fix to show proper convergence stats 2015-06-25 12:28:35 -03:00
cloexec.h perf tools: Fix build errors with mipsel-linux-uclibc compiler 2015-08-05 16:56:16 -03:00
color.c perf tools: Do not include escape sequences in color_vfprintf return 2015-08-05 16:46:06 -03:00
color.h perf tools: Remove trail argument to color vsprintf 2015-08-05 16:44:02 -03:00
comm.c perf comm: Use atomic.h for refcounting 2015-05-27 12:21:43 -03:00
comm.h perf tools: Add facility to export data in database-friendly way 2014-10-29 10:32:49 -02:00
config.c perf tools: Introduce llvm config options 2015-08-07 10:16:59 -03:00
counts.c perf stat: Move perf_counts struct and functions into separate object 2015-08-08 14:16:49 -03:00
counts.h perf stat: Move perf_counts struct and functions into separate object 2015-08-08 14:16:49 -03:00
cpumap.c perf cpu_map: Add cpu_map__empty_new function 2015-10-27 15:05:36 -03:00
cpumap.h perf cpu_map: Add cpu_map__empty_new function 2015-10-27 15:05:36 -03:00
ctype.c
data-convert-bt.c perf data: Fix signedness of value 2015-04-29 10:37:49 -03:00
data-convert-bt.h perf data: Support using -f to override perf.data file ownership for 'convert' 2015-04-02 13:18:52 -03:00
data.c perf util: Replace strerror with strerror_r for thread-safety 2014-08-15 10:58:35 -03:00
data.h perf tools: Add perf_data_file__write interface 2013-12-02 09:22:46 -03:00
db-export.c perf db-export: Fix thread ref-counting 2015-05-29 12:43:39 -03:00
db-export.h perf db-export: No need to have ->thread twice in struct export_sample 2015-04-02 13:18:43 -03:00
debug.c perf tools: Introduce veprintf 2015-08-06 15:30:38 -03:00
debug.h perf tools: Introduce veprintf 2015-08-06 15:30:38 -03:00
dso.c perf symbols: Fix dso lookup by long name and missing buildids 2015-11-13 11:14:36 -03:00
dso.h perf symbols: Fix dso lookup by long name and missing buildids 2015-11-13 11:14:36 -03:00
dwarf-aux.c perf probe: Fix to add missed brace around if block 2015-08-13 14:51:26 -03:00
dwarf-aux.h perf probe: Ignore tail calls to probed functions 2015-05-14 10:05:09 -03:00
env.c perf env: Introduce read_cpu_topology_map() method 2015-09-14 12:50:28 -03:00
env.h perf env: Introduce read_cpu_topology_map() method 2015-09-14 12:50:28 -03:00
environment.c perf report: Fix some option handling on --stdio 2015-05-14 10:05:22 -03:00
event.c perf tools: Fix handling read result using a signed variable 2015-10-06 18:04:59 -03:00
event.h perf session: Warn when AUX data has been lost 2015-09-28 16:51:33 -03:00
evlist.c perf tools: Export perf_event_attr__set_max_precise_ip() 2015-10-05 16:16:20 -03:00
evlist.h perf tools: Export perf_event_attr__set_max_precise_ip() 2015-10-05 16:16:20 -03:00
evsel.c perf bpf: Attach eBPF filter to perf event 2015-10-29 17:16:22 -03:00
evsel.h perf bpf: Attach eBPF filter to perf event 2015-10-29 17:16:22 -03:00
exec_cmd.c
exec_cmd.h
find-vdso-map.c perf tools: Build programs to copy 32-bit compatibility 2014-10-29 10:32:48 -02:00
generate-cmdlist.sh tools/perf: Standardize feature support define names to: HAVE_{FEATURE}_SUPPORT 2013-10-09 08:48:28 +02:00
header.c Merge branch 'perf/urgent' into perf/core, to resolve a conflict 2015-09-16 09:19:56 +02:00
header.h perf env: Move perf_env out of header.h and session.c into separate object 2015-09-14 12:50:19 -03:00
help.c perf tools: Use zfree to help detect use after free bugs 2013-12-27 17:08:19 -03:00
help.h
hist.c perf tools: Setup proper width for symbol_iaddr field 2015-10-05 16:33:41 -03:00
hist.h perf tools: Add support for sorting on the iaddr 2015-10-05 16:32:00 -03:00
intel-bts.c perf tools: Fix use of wrong event when processing exit events 2015-09-02 17:46:26 -03:00
intel-bts.h perf tools: Add Intel BTS support 2015-08-21 11:34:10 -03:00
intel-pt.c perf machine: Add method for common kernel_map(FUNCTION) operation 2015-09-30 18:34:29 -03:00
intel-pt.h perf tools: Pass Intel PT information for decoding MTC and CYC 2015-08-24 17:46:43 -03:00
intlist.c perf util: Add findnew method to intlist 2013-10-14 10:28:48 -03:00
intlist.h perf util: Add findnew method to intlist 2013-10-14 10:28:48 -03:00
kvm-stat.h perf kvm: Support using -f to override perf.data.guest file ownership 2015-04-02 13:18:47 -03:00
levenshtein.c
levenshtein.h
llvm-utils.c perf tools: Make fetch_kernel_version() publicly available 2015-11-06 15:57:18 -03:00
llvm-utils.h perf tests: Add LLVM test for eBPF on-the-fly compiling 2015-08-07 10:57:24 -03:00
lzma.c perf tools: Add lzma decompression support for kernel module 2015-03-21 14:53:40 -03:00
machine.c perf symbols: Fix dso lookup by long name and missing buildids 2015-11-13 11:14:36 -03:00
machine.h perf machine: Add method for common kernel_map(FUNCTION) operation 2015-09-30 18:34:29 -03:00
map.c perf tools: Insert split maps correctly into origin group 2015-11-05 11:39:38 -03:00
map.h perf maps: Introduce maps__find_symbol_by_name() 2015-09-30 18:34:25 -03:00
ordered-events.c perf ordered_events: Clear the progress bar at the end of a flush 2015-08-24 17:16:22 -03:00
ordered-events.h perf ordered_samples: Remove references to perf_{evlist,tool} and machines 2015-03-31 17:52:32 -03:00
pager.c perf report: Fix some option handling on --stdio 2015-05-14 10:05:22 -03:00
parse-branch-options.c perf record: Add ability to sample call branches 2015-10-20 10:30:55 +02:00
parse-branch-options.h perf tools: Move branch option parsing to own file 2015-05-27 21:02:17 -03:00
parse-events.c perf bpf: Improve BPF related error messages 2015-11-06 17:14:20 -03:00
parse-events.h perf tools: Compile scriptlets to BPF objects when passing '.c' to --event 2015-10-29 17:16:23 -03:00
parse-events.l perf tools: Compile scriptlets to BPF objects when passing '.c' to --event 2015-10-29 17:16:23 -03:00
parse-events.y perf tools: Compile scriptlets to BPF objects when passing '.c' to --event 2015-10-29 17:16:23 -03:00
parse-options.c perf tools: Search for more options when passing args to -h 2015-10-27 17:35:58 -03:00
parse-options.h perf tools: Introduce usage_with_options_msg() 2015-10-27 09:28:44 -03:00
parse-regs-options.c perf record: Add ability to name registers to record 2015-08-31 18:01:33 -03:00
parse-regs-options.h perf record: Add ability to name registers to record 2015-08-31 18:01:33 -03:00
path.c tools/perf: Turn strlcpy() into a __weak function 2013-10-09 08:48:49 +02:00
perf_regs.c perf tools: Fix build break on powerpc due to sample_reg_masks 2015-09-30 18:34:27 -03:00
perf_regs.h perf tools: Fix build break on powerpc due to sample_reg_masks 2015-09-30 18:34:27 -03:00
PERF-VERSION-GEN perf tools: Fix version when building out of tree 2013-11-07 10:40:47 -03:00
pmu.c perf list: Honour 'event_glob' whem printing selectable PMUs 2015-10-02 15:28:16 -03:00
pmu.h perf tools: Add perf_pmu__format_bits() 2015-08-06 16:49:01 -03:00
pmu.l
pmu.y
probe-event.c perf bpf: Allow BPF program config probing options 2015-11-18 17:51:04 -03:00
probe-event.h perf probe: Export init/exit_probe_symbol_maps() 2015-09-15 09:48:32 -03:00
probe-file.c perf probe: Verify parameters in two functions 2015-11-11 18:41:32 -03:00
probe-file.h perf probe: Print deleted events in cmd_probe() 2015-09-04 12:43:44 -03:00
probe-finder.c perf probe: Clear probe_trace_event when add_probe_trace_event() fails 2015-11-13 12:28:09 -03:00
probe-finder.h perf probe: Introduce probe_conf global configs 2015-05-08 16:26:26 -03:00
pstack.c perf tools: Introduce pstack_peek() 2015-05-05 18:13:22 -03:00
pstack.h perf tools: Introduce pstack_peek() 2015-05-05 18:13:22 -03:00
python-ext-sources perf stat: Move perf_counts struct and functions into separate object 2015-08-08 14:16:49 -03:00
python.c perf python: Support the PERF_RECORD_SWITCH event 2015-10-07 19:41:50 -03:00
quote.c
quote.h
rblist.c perf util: Add findnew method to intlist 2013-10-14 10:28:48 -03:00
rblist.h perf util: Add findnew method to intlist 2013-10-14 10:28:48 -03:00
record.c perf tools: Add a helper function to probe whether cpu-wide tracing is possible 2015-08-17 11:08:37 -03:00
run-command.c perf util: Replace strerror with strerror_r for thread-safety 2014-08-15 10:58:35 -03:00
run-command.h
session.c perf session: Add missing newlines to some pr_err() calls 2015-11-11 18:41:31 -03:00
session.h perf top: Register idle thread 2015-10-01 09:54:33 -03:00
setup.py tools lib api: Rename libapikfs.a to libapi.a 2015-02-12 17:55:18 -03:00
sigchain.c
sigchain.h
sort.c perf tools: Introduce hpp_dimension__add_output function 2015-10-06 18:04:59 -03:00
sort.h perf tools: Introduce hpp_dimension__add_output function 2015-10-06 18:04:59 -03:00
srcline.c perf tools: Always use non inlined file name for 'srcfile' sort key 2015-09-02 16:30:46 -03:00
stat-shadow.c perf stat: Move sw clock metrics printout to stat-shadow 2015-11-04 15:11:41 -03:00
stat.c perf cpu_map: Add data arg to cpu_map__build_map callback 2015-10-19 18:04:01 -03:00
stat.h perf stat: Add AGGR_UNSET mode 2015-10-19 18:02:07 -03:00
strbuf.c perf tools: Introduce usage_with_options_msg() 2015-10-27 09:28:44 -03:00
strbuf.h perf tools: Introduce usage_with_options_msg() 2015-10-27 09:28:44 -03:00
strfilter.c perf tools: Add strfilter__string to recover rules string 2015-05-04 12:43:54 -03:00
strfilter.h perf tools: Add strfilter__string to recover rules string 2015-05-04 12:43:54 -03:00
string.c tools: Adopt memdup() from tools/perf, moving it to tools/lib/string.c 2015-11-18 17:51:02 -03:00
strlist.c perf strlist: Make parse_list() private 2015-07-20 14:51:07 -03:00
strlist.h perf strlist: Make parse_list() private 2015-07-20 14:51:07 -03:00
svghelper.c perf tools: Add reference counting for cpu_map object 2015-06-25 15:15:50 -03:00
svghelper.h perf timechart: Implement IO mode 2014-07-10 00:22:54 +02:00
symbol-elf.c perf tools: Fix copying of /proc/kcore 2015-09-25 10:45:50 -03:00
symbol-minimal.c perf symbols: Fix type error when reading a build-id 2015-10-28 10:02:00 -03:00
symbol.c perf symbols: Allow forcing reading of non-root owned files by root 2015-11-12 18:58:18 -03:00
symbol.h perf symbols: Allow forcing reading of non-root owned files by root 2015-11-12 18:58:18 -03:00
target.c perf target: Simplify handling of strerror_r return 2015-03-24 12:08:30 -03:00
target.h perf target: Move the checking of which map function to call into function. 2013-12-04 13:46:37 -03:00
thread_map.c perf/core improvements and fixes: 2015-07-21 07:58:06 +02:00
thread_map.h perf thrad_map: Add comm string into array 2015-06-26 11:07:01 -03:00
thread-stack.c perf tools: Ensure thread-stack is flushed 2015-06-19 16:03:33 -03:00
thread-stack.h perf tools: Ensure thread-stack is flushed 2015-06-19 16:03:33 -03:00
thread.c perf tools: Avoid deadlock when map_groups are broken 2015-08-19 14:15:09 -03:00
thread.h perf tools: Elliminate alignment holes 2015-05-18 10:17:33 -03:00
tool.h perf tools: Add new PERF_RECORD_SWITCH event 2015-07-23 22:51:13 -03:00
top.c perf tools: Rename 'perf_record_opts' to 'record_opts 2013-12-19 14:43:45 -03:00
top.h tools: Consolidate types.h 2014-05-01 21:22:39 +02:00
trace-event-info.c tools lib api fs: Move tracing_path interface into api/fs/tracing_path.c 2015-09-04 12:00:45 -03:00
trace-event-parse.c perf tools: Stop reading the kallsyms data from perf.data 2015-07-23 22:51:11 -03:00
trace-event-read.c perf tools: Stop reading the kallsyms data from perf.data 2015-07-23 22:51:11 -03:00
trace-event-scripting.c perf scripting: No need to pass thread twice to the scripting callbacks 2015-04-02 13:18:41 -03:00
trace-event.c perf evsel: Propagate error info from tp_format 2015-09-15 09:48:33 -03:00
trace-event.h perf scripting python: Allow for max_stack greater than PERF_MAX_STACK_DEPTH 2015-09-28 17:09:12 -03:00
tsc.c perf tools: Move rdtsc() function 2014-07-23 11:48:11 -03:00
tsc.h perf tools: Move rdtsc() function 2014-07-23 11:48:11 -03:00
unwind-libdw.c perf callchains: Use thread->mg->machine 2014-10-29 10:32:46 -02:00
unwind-libdw.h perf tools: Add libdw DWARF post unwind support 2014-02-24 09:29:36 -03:00
unwind-libunwind.c perf unwind: Pass symbol source to libunwind 2015-10-29 17:48:38 -03:00
unwind.h perf callchains: Use thread->mg->machine 2014-10-29 10:32:46 -02:00
usage.c perf test: Suppress libtraceevent warnings 2015-10-19 14:58:10 -03:00
util.c perf tools: Make fetch_kernel_version() publicly available 2015-11-06 15:57:18 -03:00
util.h perf bpf: Improve BPF related error messages 2015-11-06 17:14:20 -03:00
values.c perf tools: Use zfree to help detect use after free bugs 2013-12-27 17:08:19 -03:00
values.h tools: Consolidate types.h 2014-05-01 21:22:39 +02:00
vdso.c perf tools: Fix lockup using 32-bit compat vdso 2015-07-07 11:05:08 -03:00
vdso.h perf machine: Fix up vdso methods names 2015-05-29 12:43:44 -03:00
wrapper.c
xyarray.c perf tools: Introduce xyarray__reset function 2015-06-16 10:34:39 -03:00
xyarray.h perf tools: Introduce xyarray__reset function 2015-06-16 10:34:39 -03:00
zlib.c perf tools: Add gzip decompression support for kernel module 2014-11-05 10:11:26 -03:00