Oleg Nesterov
ee2f6a6b39
uprobes: Change handle_swbp() to send SIGTRAP with si_code=SI_KERNEL, to fix GDB regression ...
commit fe5ed7ab99c656bd2f5b79b49df0e9ebf2cead8a upstream.
If a tracee is uprobed and it hits int3 inserted by debugger, handle_swbp()
does send_sig(SIGTRAP, current, 0) which means si_code == SI_USER. This used
to work when this code was written, but then GDB started to validate si_code
and now it simply can't use breakpoints if the tracee has an active uprobe:
# cat test.c
void unused_func(void)
{
}
int main(void)
{
return 0;
}
# gcc -g test.c -o test
# perf probe -x ./test -a unused_func
# perf record -e probe_test:unused_func gdb ./test -ex run
GNU gdb (GDB) 10.0.50.20200714-git
...
Program received signal SIGTRAP, Trace/breakpoint trap.
0x00007ffff7ddf909 in dl_main () from /lib64/ld-linux-x86-64.so.2
(gdb)
The tracee hits the internal breakpoint inserted by GDB to monitor shared
library events but GDB misinterprets this SIGTRAP and reports a signal.
Change handle_swbp() to use force_sig(SIGTRAP), this matches do_int3_user()
and fixes the problem.
This is the minimal fix for -stable, arch/x86/kernel/uprobes.c is equally
wrong; it should use send_sigtrap(TRAP_TRACE) instead of send_sig(SIGTRAP),
but this doesn't confuse GDB and needs another x86-specific patch.
Reported-by: Aaron Merey <amerey@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200723154420.GA32043@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-29 10:18:29 +02:00
bpf: Check correct cred for CAP_SYSLOG in bpf_dump_raw_ok()
2020-07-16 08:16:45 +02:00
cgroup: fix cgroup_sk_alloc() for sk_clone_lock()
2020-07-22 09:32:49 +02:00
kgdb: Avoid suspicious RCU usage warning
2020-07-09 09:37:51 +02:00
dma-direct: fix data truncation in dma_direct_get_required_mask()
2020-04-29 16:33:00 +02:00
uprobes: Change handle_swbp() to send SIGTRAP with si_code=SI_KERNEL, to fix GDB regression
2020-07-29 10:18:29 +02:00
kernel/gcov/fs.c: gcov_seq_next() should increase position index
2020-04-29 16:33:00 +02:00
genirq/affinity: Handle affinity setting on inactive interrupts correctly
2020-07-22 09:33:16 +02:00
locktorture: Print ratio of acquisitions, not failures
2020-04-23 10:36:44 +02:00
PM: hibernate: Freeze kernel threads in software_resume()
2020-05-06 08:15:09 +02:00
printk: queue wake_up_klogd irq_work only if per-CPU areas are ready
2020-05-02 08:48:42 +02:00
rcu: Allow only one expedited GP to run concurrently with wakeups
2020-03-05 16:43:50 +01:00
sched/fair: handle case of task_h_load() returning 0
2020-07-22 09:33:16 +02:00
timer: Fix wheel index calculation on last level
2020-07-22 09:33:14 +02:00
ring-buffer: Zero out time extend if it is nested and not absolute
2020-06-30 15:37:10 -04:00
audit: fix a net reference leak in audit_list_rules_send()
2020-06-22 09:30:59 +02:00
audit: fix a net reference leak in audit_list_rules_send()
2020-06-22 09:30:59 +02:00
audit_get_nd(): don't unlock parent too early
2019-11-10 11:56:55 -05:00
audit: fix a net reference leak in audit_list_rules_send()
2020-06-22 09:30:59 +02:00
sched/core: Fix illegal RCU from offline CPUs
2020-06-22 09:31:01 +02:00
kernel/cpu_pm: Fix uninitted local in cpu_pm
2020-06-22 09:31:22 +02:00
keys: Fix request_key() cache
2020-01-17 19:48:42 +01:00
kernel/elfcore.c: include proper prototypes
2019-09-25 17:51:39 -07:00
exit: Move preemption fixup up, move blocking operations down
2020-06-22 09:31:01 +02:00
fork: prevent accidental access to clone3 features
2020-05-20 08:20:22 +02:00
Revert "libata, freezer: avoid block device removal while system is frozen"
2019-10-06 09:11:37 -06:00
futex: Unbreak futex hashing
2020-03-25 08:25:58 +01:00
kheaders: substituting --sort in archive creation
2019-10-17 09:08:19 +09:00
kallsyms: Refactor kallsyms_show_value() to take cred
2020-07-16 08:16:44 +02:00
kexec: bail out upon SIGKILL when allocating memory.
2019-09-25 17:51:40 -07:00
Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
2019-09-28 08:14:15 -07:00
kmod: make request_module() return an error when autoloading is disabled
2020-04-17 10:50:22 +02:00
kprobes: Do not expose probe addresses to non-CAP_SYSLOG
2020-07-16 08:16:45 +02:00
kthread: make __kthread_queue_delayed_work static
2019-10-16 09:20:58 -07:00
Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity
2019-09-27 19:37:27 -07:00
module: Do not expose section addresses to non-CAP_SYSLOG
2020-07-16 08:16:45 +02:00
x86/mm: split vmalloc_sync_all()
2020-03-25 08:25:58 +01:00
padata: add separate cpuhp node for CPUHP_PADATA_DEAD
2020-06-17 16:40:22 +02:00
panic: ensure preemption is disabled during panic()
2019-10-07 15:47:19 -07:00
ptrace: reintroduce usage of subjective credentials in ptrace_has_cap()
2020-01-23 08:22:36 +01:00
kernel/relay.c: handle alloc_percpu returning NULL in relay_open
2020-06-07 13:18:47 +02:00
/dev/mem: Revoke mappings when a driver claims the region
2020-06-24 17:50:35 +02:00
seccomp: Add missing compat_ioctl for notify
2020-04-17 10:50:09 +02:00
signal: check sig before setting info in kill_pid_usb_asyncio
2020-05-02 08:48:55 +02:00
stacktrace: Don't skip first entry on noncurrent tasks
2019-11-04 21:19:25 +01:00
stop_machine: Avoid potential race behaviour
2019-10-17 12:47:12 +02:00
kernel: sysctl: make drop_caches write-only
2020-01-04 19:18:32 +01:00
taskstats: fix data-race
2020-01-09 10:19:54 +01:00
umh: fix memory leak on execve failure
2020-05-20 08:20:13 +02:00
watchdog/softlockup: Enforce that timestamp is valid on boot
2020-02-24 08:36:52 +01:00
workqueue: don't use wq_select_unbound_cpu() for bound works
2020-03-18 07:17:50 +01:00
ee2f6a6b39