Re: [PATCH v2] tracing/x86: Update syscall trace events to handle new x86 syscall func names

From: Arnaldo Carvalho de Melo
Date: Wed Apr 18 2018 - 11:02:29 EST

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Em Wed, Apr 18, 2018 at 10:36:06AM -0400, Steven Rostedt escreveu:
> On Wed, 18 Apr 2018 09:53:22 -0300
> Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> wrote:
> > Em Tue, Apr 17, 2018 at 05:41:28PM -0400, Steven Rostedt escreveu:
> > > On Tue, 17 Apr 2018 15:13:04 -0300 Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> wrote:
> > > > Yeah, failing:

> > > > [root@jouet ~]# strace -e openat -e file perf test -F -v "mmap interface" |& grep syscalls
> > > > openat(AT_FDCWD, "/sys/kernel/debug/tracing/events/syscalls/sys_enter_getsid/format", O_RDONLY) = 3
> > > > openat(AT_FDCWD, "/sys/kernel/debug/tracing/events/syscalls/sys_enter_getppid/format", O_RDONLY) = -1 ENOENT (No such file or directory)
> >
> > > It doesn't have to do with the number of parameters, not everything
> > > has "__x64" on it.

> > > Try this patch:

> > Trying...

> You're keeping me in suspense!

I switched locations, had trouble reconnecting, those tests are ok now,
there is just one case left, related to the syscall routines renames,
but not related to the syscalls:sys_{enter,exit}_NAME tracepoints:

[root@jouet ~]# perf test
1: vmlinux symtab matches kallsyms : Ok
2: Detect openat syscall event : Ok
3: Detect openat syscall event on all cpus : Ok
4: Read samples using the mmap interface : Ok
5: Test data source output : Ok
6: Parse event definition strings : Ok
7: Simple expression parser : Ok
8: PERF_RECORD_* events & perf_sample fields : Ok
9: Parse perf pmu format : Ok
10: DSO data read : Ok
11: DSO data cache : Ok
12: DSO data reopen : Ok
13: Roundtrip evsel->name : Ok
14: Parse sched tracepoints fields : Ok
15: syscalls:sys_enter_openat event fields : Ok
16: Setup struct perf_event_attr : Ok
17: Match and link multiple hists : Ok
18: 'import perf' in python : Ok
19: Breakpoint overflow signal handler : Ok
20: Breakpoint overflow sampling : Ok
21: Breakpoint accounting : Ok
22: Number of exit events of a simple workload : Ok
23: Software clock events period values : Ok
24: Object code reading : Ok
25: Sample parsing : Ok
26: Use a dummy software event to keep tracking : Ok
27: Parse with no sample_id_all bit set : Ok
28: Filter hist entries : Ok
29: Lookup mmap thread : Ok
30: Share thread mg : Ok
31: Sort output of hist entries : Ok
32: Cumulate child hist entries : Ok
33: Track with sched_switch : Ok
34: Filter fds with revents mask in a fdarray : Ok
35: Add fd to a fdarray, making it autogrow : Ok
36: kmod_path__parse : Ok
37: Thread map : Ok
38: LLVM search and compile :
38.1: Basic BPF llvm compile : Ok
38.2: kbuild searching : Ok
38.3: Compile source for BPF prologue generation : Ok
38.4: Compile source for BPF relocation : Ok
39: Session topology : Ok
40: BPF filter :
40.1: Basic BPF filtering : FAILED!
40.2: BPF pinning : Skip
40.3: BPF prologue generation : Skip
40.4: BPF relocation checker : Skip
41: Synthesize thread map : Ok
42: Remove thread map : Ok
43: Synthesize cpu map : Ok
44: Synthesize stat config : Ok
45: Synthesize stat : Ok
46: Synthesize stat round : Ok
47: Synthesize attr update : Ok
48: Event times : Ok
49: Read backward ring buffer : Ok
50: Print cpu map : Ok
51: Probe SDT events : Ok
52: is_printable_array : Ok
53: Print bitmap : Ok
54: perf hooks : Ok
55: builtin clang support : Skip (not compiled in)
56: unit_number__scnprintf : Ok
57: mem2node : Ok
58: x86 rdpmc : Ok
59: Convert perf time to TSC : Ok
60: DWARF unwind : Ok
61: x86 instruction decoder - new instructions : Ok
62: Use vfs_getname probe to get syscall args filenames : Ok
63: probe libc's inet_pton & backtrace it with ping : Ok
64: Check open filename arg using perf trace + vfs_getname: Ok
65: probe libc's inet_pton & backtrace it with ping : Ok
66: Add vfs_getname probe to get syscall args filenames : Ok
[root@jouet ~]#

If we use -v for that test we see the problem:

To the point:

Probe point 'SyS_epoll_pwait' not found.

This is not there anymore, I'll change this test to first figure out
what is the syscall routine for the epoll_pwait syscall so that it works
with pre-syscall-routines-rename and after that.

- Arnaldo

all details:

[root@jouet ~]# perf test -v BPF
40: BPF filter :
40.1: Basic BPF filtering :
--- start ---
test child forked, pid 13225
Kernel build dir is set to /lib/modules/4.17.0-rc1-00024-g7e4e440a91c8-dirty/build
set env: KBUILD_DIR=/lib/modules/4.17.0-rc1-00024-g7e4e440a91c8-dirty/build
unset env: KBUILD_OPTS
include option is set to -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/7/include -I/home/acme/git/linux/arch/x86/include -I./arch/x86/include/generated -I/home/acme/git/linux/include -I./include -I/home/acme/git/linux/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/home/acme/git/linux/include/uapi -I./include/generated/uapi -include /home/acme/git/linux/include/linux/kconfig.h
set env: NR_CPUS=4
set env: LINUX_VERSION_CODE=0x41100
set env: CLANG_EXEC=/usr/lib64/ccache/clang
set env: CLANG_OPTIONS=-xc
set env: KERNEL_INC_OPTIONS= -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/7/include -I/home/acme/git/linux/arch/x86/include -I./arch/x86/include/generated -I/home/acme/git/linux/include -I./include -I/home/acme/git/linux/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/home/acme/git/linux/include/uapi -I./include/generated/uapi -include /home/acme/git/linux/include/linux/kconfig.h
set env: WORKING_DIR=/lib/modules/4.17.0-rc1-00024-g7e4e440a91c8-dirty/build
set env: CLANG_SOURCE=-
llvm compiling command template: echo '/*
* bpf-script-example.c
* Test basic LLVM building
*/
#ifndef LINUX_VERSION_CODE
# error Need LINUX_VERSION_CODE
# error Example: for 4.2 kernel, put 'clang-opt="-DLINUX_VERSION_CODE=0x40200" into llvm section of ~/.perfconfig'
#endif
#define BPF_ANY 0
#define BPF_MAP_TYPE_ARRAY 2
#define BPF_FUNC_map_lookup_elem 1
#define BPF_FUNC_map_update_elem 2

static void *(*bpf_map_lookup_elem)(void *map, void *key) =
(void *) BPF_FUNC_map_lookup_elem;
static void *(*bpf_map_update_elem)(void *map, void *key, void *value, int flags) =
(void *) BPF_FUNC_map_update_elem;

struct bpf_map_def {
unsigned int type;
unsigned int key_size;
unsigned int value_size;
unsigned int max_entries;
};

#define SEC(NAME) __attribute__((section(NAME), used))
struct bpf_map_def SEC("maps") flip_table = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(int),
.max_entries = 1,
};

SEC("func=SyS_epoll_pwait")
int bpf_func__SyS_epoll_pwait(void *ctx)
{
int ind =0;
int *flag = bpf_map_lookup_elem(&flip_table, &ind);
int new_flag;
if (!flag)
return 0;
/* flip flag and store back */
new_flag = !*flag;
bpf_map_update_elem(&flip_table, &ind, &new_flag, BPF_ANY);
return new_flag;
}
char _license[] SEC("license") = "GPL";
int _version SEC("version") = LINUX_VERSION_CODE;
' | $CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS -DLINUX_VERSION_CODE=$LINUX_VERSION_CODE $CLANG_OPTIONS $KERNEL_INC_OPTIONS -Wno-unused-value -Wno-pointer-sign -working-directory $WORKING_DIR -c "$CLANG_SOURCE" -target bpf -O2 -o -
llvm compiling command : echo '/*
* bpf-script-example.c
* Test basic LLVM building
*/
#ifndef LINUX_VERSION_CODE
# error Need LINUX_VERSION_CODE
# error Example: for 4.2 kernel, put 'clang-opt=-DLINUX_VERSION_CODE=0x40200 into llvm section of ~/.perfconfig'
#endif
#define BPF_ANY 0
#define BPF_MAP_TYPE_ARRAY 2
#define BPF_FUNC_map_lookup_elem 1
#define BPF_FUNC_map_update_elem 2

static void *(*bpf_map_lookup_elem)(void *map, void *key) =
(void *) BPF_FUNC_map_lookup_elem;
static void *(*bpf_map_update_elem)(void *map, void *key, void *value, int flags) =
(void *) BPF_FUNC_map_update_elem;

struct bpf_map_def {
unsigned int type;
unsigned int key_size;
unsigned int value_size;
unsigned int max_entries;
};

#define SEC(NAME) __attribute__((section(NAME), used))
struct bpf_map_def SEC(maps) flip_table = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(int),
.value_size = sizeof(int),
.max_entries = 1,
};

SEC(func=SyS_epoll_pwait)
int bpf_func__SyS_epoll_pwait(void *ctx)
{
int ind =0;
int *flag = bpf_map_lookup_elem(&flip_table, &ind);
int new_flag;
if (!flag)
return 0;
/* flip flag and store back */
new_flag = !*flag;
bpf_map_update_elem(&flip_table, &ind, &new_flag, BPF_ANY);
return new_flag;
}
char _license[] SEC(license) = GPL;
int _version SEC(version) = LINUX_VERSION_CODE;
' | /usr/lib64/ccache/clang -D__KERNEL__ -D__NR_CPUS__=4 -DLINUX_VERSION_CODE=0x41100 -xc -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/7/include -I/home/acme/git/linux/arch/x86/include -I./arch/x86/include/generated -I/home/acme/git/linux/include -I./include -I/home/acme/git/linux/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/home/acme/git/linux/include/uapi -I./include/generated/uapi -include /home/acme/git/linux/include/linux/kconfig.h -Wno-unused-value -Wno-pointer-sign -working-directory /lib/modules/4.17.0-rc1-00024-g7e4e440a91c8-dirty/build -c - -target bpf -O2 -o -
libbpf: loading object '[basic_bpf_test]' from buffer
libbpf: section(1) .strtab, size 122, link 0, flags 0, type=3
libbpf: skip section(1) .strtab
libbpf: section(2) .text, size 0, link 0, flags 6, type=1
libbpf: skip section(2) .text
libbpf: section(3) func=SyS_epoll_pwait, size 192, link 0, flags 6, type=1
libbpf: found program func=SyS_epoll_pwait
libbpf: section(4) .relfunc=SyS_epoll_pwait, size 32, link 8, flags 0, type=9
libbpf: section(5) maps, size 16, link 0, flags 3, type=1
libbpf: section(6) license, size 4, link 0, flags 3, type=1
libbpf: license of [basic_bpf_test] is GPL
libbpf: section(7) version, size 4, link 0, flags 3, type=1
libbpf: kernel version of [basic_bpf_test] is 41100
libbpf: section(8) .symtab, size 168, link 1, flags 0, type=2
libbpf: maps in [basic_bpf_test]: 1 maps in 16 bytes
libbpf: map 0 is "flip_table"
libbpf: collecting relocating info for: 'func=SyS_epoll_pwait'
libbpf: relo for 6 value 0 name 81
libbpf: relocation: insn_idx=4
libbpf: relocation: find map 0 (flip_table) for insn 4
libbpf: relo for 6 value 0 name 81
libbpf: relocation: insn_idx=17
libbpf: relocation: find map 0 (flip_table) for insn 17
bpf: config program 'func=SyS_epoll_pwait'
symbol:SyS_epoll_pwait file:(null) line:0 offset:0 return:0 lazy:(null)
bpf: config 'func=SyS_epoll_pwait' is ok
Looking at the vmlinux_path (8 entries long)
Using /lib/modules/4.17.0-rc1-00024-g7e4e440a91c8-dirty/build/vmlinux for symbols
Open Debuginfo file: /lib/modules/4.17.0-rc1-00024-g7e4e440a91c8-dirty/build/vmlinux
Try to find probe point from debuginfo.
Probe point 'SyS_epoll_pwait' not found.
bpf_probe: failed to convert perf probe events
Failed to add events selected by BPF
test child finished with -1
---- end ----
BPF filter subtest 0: FAILED!
40.2: BPF pinning :
--- force skipped ---
BPF filter subtest 1: Skip
40.3: BPF prologue generation :
--- force skipped ---
BPF filter subtest 2: Skip
40.4: BPF relocation checker :
--- force skipped ---
BPF filter subtest 3: Skip
[root@jouet ~]#

Next message: Kirill Tkhai: "Re: [PATCH v2 01/12] mm: Assign id to every memcg-aware shrinker"
Previous message: Petr Mladek: "Re: [PATCH 2/2] printk: wake up klogd in vprintk_emit"
In reply to: Steven Rostedt: "Re: [PATCH v2] tracing/x86: Update syscall trace events to handle new x86 syscall func names"
Next in thread: Arnaldo Carvalho de Melo: "Re: [PATCH v2] tracing/x86: Update syscall trace events to handle new x86 syscall func names"
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