23 Commits

Author SHA1 Message Date
048d1885fa Implement -e kvm= option on all architectures
Make -e kvm= interface available on all architectures by adding a stub
on those architectures that do not have <linux/kvm.h>.

* filter_qualify.c (qualify_kvm): Define unconditionally.
(qual_options): Define qualify_kvm entry unconditionally.
* strace.c (usage): Mention kvm argument of -e option unconditionally.
2018-07-11 00:00:57 +00:00
b39cb830af Upgrade invalid -e kvm= argument to a fatal error
* filter_qualify.c (qualify_kvm): Call error_msg_and_die instead of
error_msg in case of invalid -e kvm= argument.
* tests/options-syntax.test: Check it.
2018-07-10 16:10:38 +00:00
Masatake YAMATO
b7416438b8 kvm: attach the exit reason of vcpu as auxstr to KVM_RUN output
In KVM, a virtual machine implementation like Qemu can access a vcpu
via ioctl.  KVM_RUN is an ioctl command to enter vcpu.  The command
returns control for various reasons: needs of device emulation or
consuming time slices are the typical ones.  The vmi takes a different
action for the reason.

We, strace users, want to know the reason to understand kvm.  This
change prints the reason as auxstr if "-e kvm=vcpu" option is given,
and if strace runs on Linux 4.16.0 or higher, which includes commit
e46b469278a59781f9b25ff608af84892963821b, "kvm: embed vcpu id to dentry
of vcpu anon inode."

The way to get the reason is a bit complicated because the ioctl does
not return it to the userspace directly.  Instead, the vmi and kvm
communicate via an area of the process virtual memory where the fd of
vcpu is mmap'ed.  strace must peek the area to know the reason.

The change does three things: (1) recording the area for the given vcpu
when the target calls VCPU_CREATE to vcpu_info_list per tcb data field,
(2) verifying the data recorded in vcpu_info_list before doing (3), and
(3) decoding the exit reason field of the area.

The change is complicated because there is a case that strace
does not have a chance to do (1) if -p option is used.
In this case, vcpu_info data created in the step (2).

The area has more fields than "exit reason",
dumping them may be implemented in the future.

* defs.h (struct tcb) [HAVE_LINUX_KVM_H]: Add vcpu_info_list field.
[HAVE_LINUX_KVM_H]: (kvm_run_structure_decoder_init,
kvm_vcpu_info_free): New declarations.
* strace.c (usage): Add "kvm" as a new expression for -e option.
(droptcb): Call kvm_vcpu_info_free.
* filter_qualify.c (qualify_kvm): New function calling
kvm_run_structure_decoder_init to enable for attaching the exit
reason to auxstr.
(qual_options): Add "kvm" as an entry.
* xlat/kvm_exit_reason.in: New file.
* kvm.c: Include xmalloc.h and mmap_cache.h.
(dump_kvm_run_structure): New static variable.
(kvm_run_structure_decoder_init): New function.
(vcpu_info): New struct definition representing the 3-tuple: vcpu file
descriptor, id of the vcpu, and mmap'ed entry.
(vcpu_find, vcpu_alloc, vcpu_register, vcpu_getinfo,
kvm_vcpu_info_free): New functions to access tcb's vcpu_info_list
field and vcpu_info data type.
(is_map_for_file, map_len): New helper functions.
(kvm_ioclt_run_attach_auxstr, kvm_ioctl_decode_run): New functions
decoding vcpu exit reason and attaching the decoded data to auxstr
field of tcb.
(kvm_ioctl_create_vcpu): Call vcpu_register to make an entry mapping
a file descriptor and the vcpu id associated with the fd.
(kvm_ioctl): Call kvm_ioctl_decode_run.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>
2018-07-07 10:29:02 +00:00
Eugene Syromyatnikov
883617d8b7 Implement injection of syscalls with no side effects as an alternative to -1
* defs.h (INJECT_F_SYSCALL, INJECT_ACTION_FLAGS, TCB_TAMPERED_NO_FAIL,
syscall_tampered_nofail): New macros.
(inject_data): Add scno field.
* filter_qualify.c (struct inject_personality_data): New type.
(parse_inject_token): Add "pdata" argument, parse "syscall=" option.
(parse_inject_expression): Add "pdata" argument, forward it to
parse_inject_token.
(qualify_inject_common) <pdata>: New variable array, pass it to
parse_inject_expression, copy it into inject_vec.
* syscall.c (tamper_with_syscall_entering): Inject the specified syscall
if INJECT_F_SYSCALL is set.
(tamper_with_syscall_exiting): Update the check for a failed syscall
injection.
(get_syscall_result): Update get_error invocation.
* strace.1.in: Document new syscall injection expression.
* NEWS: Mention it.

Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>
Closes: https://github.com/strace/strace/issues/26
2018-06-13 15:05:09 +00:00
Eugene Syromyatnikov
4c9ed3f146 Implement injection of negative return values
Extend the range of injected return value to the maximum, print warnings
if negative injection value can be clipped in compat personality or can
inadvertently turn into a fault injection.

* defs.h (INJECT_F_ERROR): New macro.
* filter_qualify.c (parse_inject_token): Revert type of intval local
variable back to int, check INJECT_F_ERROR along with INJECT_F_RETVAL,
use strtoull to parse retval argument, print warnings in case of retval
clipping and inadvertent fault injection.
(qualify_inject_common): Set INJECT_F_ERROR instead of INJECT_F_RETVAL.
* syscall.c (tamper_with_syscall_exiting): Check inject_data.flags
to determine whether a fault injection or retval injection has to be
performed.
(syscall_exiting_trace) <case RVAL_DECIMAL>: Explicitly print
tcp->u_rval as int if current_klongsize < sizeof(tcp->u_rval).
* tests/inject-nf.c (main): Update.
* tests/inject-nf.test: Test injection of negative return values.
* tests/qual_inject-syntax.test: Remove retval=-1 check as it is now
allowed, add checks for invalid retval parameters.

Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>
2018-03-29 01:30:09 +00:00
6905f5d2bf Move delay interface from defs.h to delay.h
* defs.h (alloc_delay_data, fill_delay_data, is_delay_timer_armed,
delay_timer_expired, arm_delay_timer, delay_tcb): Move...
* delay.h: ... to new file.
* Makefile.am (strace_SOURCES): Add it.
* filter_qualify.c: Include it.
* strace.c: Likewise.
* syscall.c: Likewise.
2018-03-28 04:29:22 +00:00
33c725f817 Turn struct inject_data.rval into an index
Add one level of indirection to decrease the size of struct inject_data
as hundreds of these structures are created for each process when
injection mechanism is activated.

* retval.h: New file.
* retval.c: Likewise.
* Makefile.am (strace_SOURCES): Add them.
* defs.h (struct inject_data): Replace rval field with rval_idx.
* filter_qualify.c: Include "retval.h".
(parse_inject_token, qualify_inject_common): Initialize
struct inject_data.rval_idx using retval_new.
* syscall.c: Include "retval.h".
(tamper_with_syscall_exiting): Obtain the value that has to be injected
using retval_get.
2018-03-28 04:29:22 +00:00
Elvira Khabirova
ba8e768a80 Implement delay injection
Add -e inject=SET:delay_enter= and -e inject=SET:delay_exit= options.

* configure.ac (AC_SEARCH_LIBS): Check for timer_create -lrt.
* delay.c: New file.
* Makefile.am (strace_SOURCES): Add it.
(strace_LDADD): Add $(timer_LIBS).
* defs.h (INJECT_F_DELAY_ENTER, INJECT_F_DELAY_EXIT,
TCB_INJECT_DELAY_EXIT, TCB_DELAYED, inject_delay_exit, syscall_delayed):
New macros.
(alloc_delay_data, fill_delay_data, is_delay_timer_created,
arm_delay_timer, delay_tcb): New prototypes.
(struct inject_data): Replace reserved field with delay_idx.
(struct tcb): Add delay_expiration_time field.
* filter_qualify.c (parse_delay_token): New function.
(parse_inject_token): Use it.
(qualify_inject_common): Initialize struct inject_opts.data.delay_idx.
* strace.c: Include <setjmp.h>
(timer_jmp_buf, timer_set): New static variables.
(timer_sighandler, restart_delayed_tcb, restart_delayed_tcbs): New
functions.
(init): Block SIGALRM, set SIGALRM handler.
(dispatch_event): Do not restart delayed syscalls.
(next_event): Unblock SIGALRM during wait4 invocation.
* syscall.c (tamper_with_syscall_entering): Arm delay timer if
INJECT_F_DELAY_ENTER injection flag is set, set TCB_INJECT_DELAY_EXIT
flag if INJECT_F_DELAY_EXIT injection flag is set.
tamper_with_syscall_exiting): Arm delay timer if inject_delay_exit.
(syscall_exiting_trace): Call tamper_with_syscall_exiting in case of
inject_delay_exit.
(syscall_exiting_finish): Clear TCB_INJECT_DELAY_EXIT flag.
* strace.1.in: Document delay injection.
* NEWS: Mention this improvement.

Co-Authored-by: Dmitry V. Levin <ldv@altlinux.org>
2018-03-22 06:23:25 +00:00
daaf8ab7fe Update copyright headers
Headers updated automatically using maint/update_copyright_years.sh
script.
2018-02-13 22:00:00 +00:00
ae8c1d5cc7 Consistently use MAX_ERRNO_VALUE
* filter_qualify.c (parse_inject_token): Replace 4095
with MAX_ERRNO_VALUE.
* negated_errno.h (is_negated_errno): Likewise.  Remove redundant
comment.
2018-02-13 05:05:13 +00:00
Eugene Syromyatnikov
b21d81db04 Change type of injected rval to kernel_long_t
* defs.h (struct inject_data): Change type of rval field to
kernel_ulong_t.
* filter_qualify.c (parse_inject_token): Use string_to_kulong instead of
string_to_uint for rval parsing.  Warn if retval is clipped in compat
personality.
2018-02-10 02:15:35 +00:00
69bd90eb80 Enhance error diagnostics about invalid syscalls in fault injection syntax
Validate syscall set before the whole fault injection syntax.

* filter_qualify.c (parse_inject_expression): Add const qualifier to
return type.  Return an empty string when no syscall set is specified.
(qualify_inject_common): Add const qualifier to "name".  Move
qualify_syscall_tokens invocation right after parse_inject_expression.
* tests/qual_fault-syntax.test: Update expected output.
* tests/qual_inject-syntax.test: Likewise.
2018-01-16 04:34:25 +00:00
f31ef8f967 filter_qualify: use loop initial declarations
* filter_qualify.c (sigstr_to_uint, find_errno_by_name,
parse_inject_expression, qualify_inject_common, qualify): Use "for" loop
initial declarations.
2018-01-16 01:09:14 +00:00
24d48dde06 Enhance error diagnostics about invalid syscalls in fault injection syntax
* basic_filters.c (qualify_syscall_tokens): Remove "name" argument,
assume its value is "system call".
* filter.h (qualify_syscall_tokens): Remove "name" argument.
All callers updated.
* tests/qual_fault-syntax.test: Update expected output.
2018-01-15 18:16:31 +00:00
5f2597ef21 filter: remove redundant braces around single line expressions
* basic_filters.c (qualify_syscall_class, qualify_syscall_name):
Rearrange the inner loop body.
(qualify_syscall_number, lookup_class, qualify_syscall_tokens,
qualify_tokens): Remove redundant braces around single line expressions.
* filter_qualify.c (qualify_inject_common): Likewise.
2018-01-15 16:23:54 +00:00
79a08404d8 filter_qualify: move memory allocation from parse_inject_expression
* filter_qualify.c (parse_inject_expression): Replace "s" and "buf"
arguments with "str" argument, use it instead of "s" and "*buf".
(qualify_inject_common): Rename "buf" to "copy", initialize it to a copy
of "str", pass "copy" to parse_inject_expression instead of "str" and
"buf".
2018-01-15 16:23:54 +00:00
ed9faa2e27 Disallow more than one signal= specification in an injection expression
Specifying several signal= specifications in an injection expressions
makes no sense.

* filter_qualify.c (parse_inject_token): Disallow second
signal= specification.
* strace.1.in: Document it.
* tests/qual_inject-syntax.test: Check it.
2017-08-28 23:38:43 +00:00
fe1ab2a53a Add "flags" field to struct inject_data
Introduce "flags" field to struct inject_data and use it instead
of magic rval and signo constants.
Due to layout of struct inject_data, this new field does not change
sizeof(struct inject_data).

* defs.h (INJECT_F_RETVAL, INJECT_F_SIGNAL): New macros.
(INJECT_OPTS_RVAL_DEFAULT): Remove macro.
(struct inject_data): Add "flags" field.
* filter_qualify.c (parse_inject_token, qualify_inject_common): Check
struct inject_data.flags instead of inject_data.rval
and inject_data.signo, do not initialize inject_opts.data.
* syscall.c (tamper_with_syscall_entering): Check struct
inject_data.flags instead of inject_data.rval and inject_data.signo.
2017-08-28 22:37:27 +00:00
4fa9ea3707 Move inject data of struct inject_opts to inject_data substructure
* defs.h (inject_data): New structure.
(struct inject_opts): Replace "signo" and "rval" fields with "data"
field of type "struct inject_data".
* filter_qualify.c (parse_inject_token, qualify_inject_common): Update
for the new layout of struct inject_opts.
* syscall.c (tamper_with_syscall_entering, tamper_with_syscall_exiting):
Likewise.

Co-authored-by: Victor Krapivensky <krapivenskiy.va@phystech.edu>
2017-08-28 22:37:27 +00:00
5d7623a502 Hide struct number_set implementation details from users
* number_set.h (number_slot_t, struct number_set): Move to number_set.c.
(struct number_set): Add forward declaration.
(read_set, write_set, signal_set): Change prototypes from objects
to pointers.
* filter_qualify.c (read_set, write_set, signal_set): Change definitions
from objects to pointers.
(abbrev_set, inject_set, raw_set, trace_set, verbose_set): Change
definitions from arrays to pointers.
(qualify_read): Initialize read_set before first use.
(qualify_write): Initialize write_set before first use.
(qualify_signals): Initialize signal_set before first use.
(qualify_trace): Initialize trace_set before first use.
(qualify_abbrev): Initialize abbrev_set before first use.
(qualify_verbose): Initialize verbose_set before first use.
(qualify_raw): Initialize raw_set before first use.
(qualify_inject_common): Initialize inject_set before first use.
* strace.c (print_signalled, print_stopped): Update signal_set usage.
* syscall.c (dumpio): Update usage of read_set and write_set.
2017-08-22 21:23:49 +00:00
ef7b7a70c1 Extend number_set interface
* number_set.h (number_set_array_is_empty, is_number_in_set_array,
add_number_to_set_array, clear_number_set_array,
invert_number_set_array, alloc_number_set_array, free_number_set_array):
New function prototypes.
* number_set.c (number_set_array_is_empty, is_number_in_set_array,
add_number_to_set_array, clear_number_set_array,
invert_number_set_array, alloc_number_set_array, free_number_set_array):
New functions.
* basic_filters.c (qualify_syscall_number, qualify_syscall_regex,
qualify_syscall_class, qualify_syscall_name): Use
add_number_to_set_array.
(qualify_syscall_tokens, qualify_tokens): Use
clear_number_set_array and invert_number_set_array.
* filter_qualify.c (qualify_inject_common): Use alloc_number_set_array,
number_set_array_is_empty, is_number_in_set_array,
add_number_to_set_array, and free_number_set_array.
(qual_flags): Use is_number_in_set_array.
2017-08-22 21:23:49 +00:00
67c97082ac Move number_set interface to separate files
* number_set.c: New file.
* number_set.h: Likewise.
* Makefile.am (strace_SOURCES): Add them.
* basic_filters.c: Include "number_set.h".
(number_slot_t, struct number_set): Move to number_set.h.
(BITS_PER_SLOT, number_setbit, number_isset, reallocate_number_set,
add_number_to_set, is_number_in_set): Move to number_set.c.
* defs.h (struct number_set): Remove forward declaration.
(read_set, write_set, signal_set, is_number_in_set): Move to number_set.h.
* filter.h (add_number_to_set): Move to number_set.h.
* filter_qualify.c: Include "number_set.h".
(number_slot_t, struct number_set): Remove.
* strace.c: Include "number_set.h".
* syscall.c: Likewise.
2017-08-22 21:23:49 +00:00
Nikolay Marchuk
b75c5b14e7 Split qualify.c into basic_filters.c and filter_qualify.c
This change also exports add_number_to_set, qualify_tokens,
and qualify_syscall_tokens.

* basic_filters.c: New file, part of qualify.c.
* filter_qualify.c: Likewise.
* filter.h: New file.
* qualify.c: Remove.
* Makefile.am (strace_SOURCES): Add new files, remove qualify.c.
2017-08-07 03:01:30 +00:00