linux/kernel
Alexei Starovoitov 8d3b7dce86 bpf: add support for %s specifier to bpf_trace_printk()
%s specifier makes bpf program and kernel debugging easier.
To make sure that trace_printk won't crash the unsafe string
is copied into stack and unsafe pointer is substituted.

The following C program:
 #include <linux/fs.h>
int foo(struct pt_regs *ctx, struct filename *filename)
{
  void *name = 0;

  bpf_probe_read(&name, sizeof(name), &filename->name);
  bpf_trace_printk("executed %s\n", name);
  return 0;
}

when attached to kprobe do_execve()
will produce output in /sys/kernel/debug/tracing/trace_pipe :
    make-13492 [002] d..1  3250.997277: : executed /bin/sh
      sh-13493 [004] d..1  3250.998716: : executed /usr/bin/gcc
     gcc-13494 [002] d..1  3250.999822: : executed /usr/lib/gcc/x86_64-linux-gnu/4.7/cc1
     gcc-13495 [002] d..1  3251.006731: : executed /usr/bin/as
     gcc-13496 [002] d..1  3251.011831: : executed /usr/lib/gcc/x86_64-linux-gnu/4.7/collect2
collect2-13497 [000] d..1  3251.012941: : executed /usr/bin/ld

Suggested-by: Brendan Gregg <brendan.d.gregg@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-08-28 16:27:27 -07:00
..
bpf bpf: fix bpf_perf_event_read() loop upper bound 2015-08-12 16:42:50 -07:00
configs kconfig: add xenconfig defconfig helper 2015-06-16 11:04:29 +01:00
debug debug: prevent entering debug mode on panic/exception. 2015-02-19 12:39:03 -06:00
events Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2015-08-21 11:44:04 -07:00
gcov gcov: add support for GCC 5.1 2015-06-30 19:44:57 -07:00
irq genirq: Introduce irq_chip_set_type_parent() helper 2015-08-20 00:25:25 +02:00
livepatch Merge branches 'for-4.1/upstream-fixes', 'for-4.2/kaslr' and 'for-4.2/upstream' into for-linus 2015-06-22 16:26:56 +02:00
locking locking/pvqspinlock: Fix kernel panic in locking-selftest 2015-07-21 10:18:07 +02:00
power Power management and ACPI fixes for v4.2-rc1 2015-07-01 14:17:44 -07:00
printk printk: improve the description of /dev/kmsg line format 2015-06-30 19:44:59 -07:00
rcu This patch series contains several clean ups and even a new trace clock 2015-06-26 14:02:43 -07:00
sched sched/fair: Test list head instead of list entry in throttle_cfs_rq() 2015-07-06 14:15:08 +02:00
time timer: Write timer->flags atomically 2015-08-18 15:31:16 +02:00
trace bpf: add support for %s specifier to bpf_trace_printk() 2015-08-28 16:27:27 -07:00
.gitignore
acct.c acct: check FMODE_CAN_WRITE 2015-04-11 22:27:55 -04:00
async.c
audit_tree.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-04-26 17:22:07 -07:00
audit_watch.c VFS: audit: d_backing_inode() annotations 2015-04-15 15:06:55 -04:00
audit.c Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit 2015-06-27 13:53:16 -07:00
audit.h Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit 2015-04-22 14:49:23 -07:00
auditfilter.c Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/audit 2015-02-11 20:07:47 -08:00
auditsc.c Fix broken audit tests for exec arg len 2015-07-08 09:33:38 -07:00
backtracetest.c
bounds.c
capability.c kernel: conditionally support non-root users, groups and capabilities 2015-04-15 16:35:22 -07:00
cgroup_freezer.c
cgroup.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2015-07-03 15:20:57 -07:00
compat.c compat: cleanup coding in compat_get_bitmap() and compat_put_bitmap() 2015-06-04 23:57:18 +02:00
configs.c
context_tracking.c context_tracking: Inherit TIF_NOHZ through forks instead of context switches 2015-05-07 12:02:51 +02:00
cpu_pm.c
cpu.c genirq: Revert sparse irq locking around __cpu_up() and move it to x86 for now 2015-07-15 10:39:17 +02:00
cpuset.c cpuset: use trialcs->mems_allowed as a temp variable 2015-08-10 11:18:41 -04:00
crash_dump.c
cred.c kernel: conditionally support non-root users, groups and capabilities 2015-04-15 16:35:22 -07:00
delayacct.c
dma.c
elfcore.c
exec_domain.c Remove rest of exec domains. 2015-04-12 21:03:31 +02:00
exit.c exit,stats: /* obey this comment */ 2015-06-25 17:00:43 -07:00
extable.c ftrace/x86/extable: Add is_ftrace_trampoline() function 2014-11-19 15:25:26 -05:00
fork.c x86/fpu, sched: Introduce CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it on x86 2015-07-18 03:42:51 +02:00
freezer.c freezer: remove obsolete comments in __thaw_task() 2014-10-21 23:44:20 +02:00
futex_compat.c
futex.c Merge branch 'sched-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-06-24 14:46:01 -07:00
groups.c kernel: conditionally support non-root users, groups and capabilities 2015-04-15 16:35:22 -07:00
hung_task.c kernel/hung_task.c: change hung_task.c to use for_each_process_thread() 2015-04-15 16:35:22 -07:00
irq_work.c percpu: Convert remaining __get_cpu_var uses in 3.18-rcX 2014-10-29 11:18:18 -04:00
jump_label.c module, jump_label: Fix module locking 2015-05-27 11:09:50 +09:30
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks locking/qrwlock: Rename QUEUE_RWLOCK to QUEUED_RWLOCKS 2015-05-12 09:46:00 +02:00
Kconfig.preempt
kexec.c kernel/panic/kexec: fix "crash_kexec_post_notifiers" option issue in oops path 2015-06-30 19:44:57 -07:00
kmod.c usermodehelper: kill the kmod_thread_locker logic 2014-12-10 17:41:17 -08:00
kprobes.c kprobes: makes kprobes/enabled works correctly for optimized kprobes. 2015-02-13 21:21:42 -08:00
ksysfs.c
kthread.c kthread: export kthread functions 2015-08-07 04:39:41 +03:00
latencytop.c
Makefile make certificate list change message more useful 2015-07-02 16:42:13 -07:00
module_signing.c
module-internal.h
module.c module: weaken locking assertion for oops path. 2015-07-29 06:13:22 +09:30
notifier.c rcu: Make SRCU optional by using CONFIG_SRCU 2015-01-06 11:04:29 -08:00
nsproxy.c bury struct proc_ns in fs/proc 2014-12-04 14:34:54 -05:00
padata.c padata: use %*pb[l] to print bitmaps including cpumasks and nodemasks 2015-02-13 21:21:38 -08:00
panic.c kernel/panic/kexec: fix "crash_kexec_post_notifiers" option issue in oops path 2015-06-30 19:44:57 -07:00
params.c Minor merge needed, due to function move. 2015-07-01 10:49:25 -07:00
pid_namespace.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-12-16 15:53:03 -08:00
pid.c fork: report pid reservation failure properly 2015-04-17 09:04:06 -04:00
profile.c profile: use %*pb[l] to print bitmaps including cpumasks and nodemasks 2015-02-13 21:21:38 -08:00
ptrace.c ptrace: ptrace_detach() can no longer race with SIGKILL 2015-04-17 09:04:06 -04:00
range.c kernel: avoid overflow in cmp_range 2015-01-17 10:02:23 +13:00
reboot.c kernel/reboot.c: add orderly_reboot for graceful reboot 2015-04-15 16:35:23 -07:00
relay.c kernel/relay.c: use kvfree() in relay_free_page_array() 2015-06-30 19:44:59 -07:00
resource.c mm: Fix bugs in region_is_ram() 2015-07-22 17:20:34 +02:00
seccomp.c seccomp, filter: add and use bpf_prog_create_from_user from seccomp 2015-05-09 17:35:05 -04:00
signal.c signal: fix information leak in copy_siginfo_to_user 2015-08-07 04:39:40 +03:00
smp.c smp: Fix error case handling in smp_call_function_*() 2015-04-19 13:19:23 -07:00
smpboot.c watchdog: add watchdog_cpumask sysctl to assist nohz 2015-06-24 17:49:40 -07:00
smpboot.h
softirq.c Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-02-09 15:24:03 -08:00
stacktrace.c stacktrace: introduce snprint_stack_trace for buffer output 2014-12-13 12:42:48 -08:00
stop_machine.c sched/stop_machine: Fix deadlock between multiple stop_two_cpus() 2015-06-19 10:03:12 +02:00
sys_ni.c kernel: conditionally support non-root users, groups and capabilities 2015-04-15 16:35:22 -07:00
sys.c prctl: more prctl(PR_SET_MM_*) checks 2015-06-25 17:00:37 -07:00
sysctl_binary.c kernel: add panic_on_warn 2014-12-10 17:41:10 -08:00
sysctl.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2015-07-03 15:20:57 -07:00
system_certificates.S
system_keyring.c
task_work.c
taskstats.c netlink: make nlmsg_end() and genlmsg_end() void 2015-01-18 01:03:45 -05:00
test_kprobes.c
torture.c rcu: Convert ACCESS_ONCE() to READ_ONCE() and WRITE_ONCE() 2015-05-27 12:56:15 -07:00
tracepoint.c
tsacct.c
uid16.c groups: Consolidate the setgroups permission checks 2014-12-05 17:19:27 -06:00
up.c
user_namespace.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2014-12-17 12:31:40 -08:00
user-return-notifier.c
user.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2014-12-17 12:31:40 -08:00
utsname_sysctl.c
utsname.c copy address of proc_ns_ops into ns_common 2014-12-04 14:34:47 -05:00
watchdog.c watchdog: add watchdog_cpumask sysctl to assist nohz 2015-06-24 17:49:40 -07:00
workqueue_internal.h
workqueue.c Minor merge needed, due to function move. 2015-07-01 10:49:25 -07:00