#
325f3fb5 |
| 10-Apr-2024 |
Zheng Yejian <zhengyejian1@huawei.com> |
kprobes: Fix possible use-after-free issue on kprobe registration
When unloading a module, its state is changing MODULE_STATE_LIVE -> MODULE_STATE_GOING -> MODULE_STATE_UNFORMED. Each change will t
kprobes: Fix possible use-after-free issue on kprobe registration
When unloading a module, its state is changing MODULE_STATE_LIVE -> MODULE_STATE_GOING -> MODULE_STATE_UNFORMED. Each change will take a time. `is_module_text_address()` and `__module_text_address()` works with MODULE_STATE_LIVE and MODULE_STATE_GOING. If we use `is_module_text_address()` and `__module_text_address()` separately, there is a chance that the first one is succeeded but the next one is failed because module->state becomes MODULE_STATE_UNFORMED between those operations.
In `check_kprobe_address_safe()`, if the second `__module_text_address()` is failed, that is ignored because it expected a kernel_text address. But it may have failed simply because module->state has been changed to MODULE_STATE_UNFORMED. In this case, arm_kprobe() will try to modify non-exist module text address (use-after-free).
To fix this problem, we should not use separated `is_module_text_address()` and `__module_text_address()`, but use only `__module_text_address()` once and do `try_module_get(module)` which is only available with MODULE_STATE_LIVE.
Link: https://lore.kernel.org/all/20240410015802.265220-1-zhengyejian1@huawei.com/
Fixes: 28f6c37a2910 ("kprobes: Forbid probing on trampoline and BPF code areas") Cc: stable@vger.kernel.org Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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#
9efd24ec |
| 19-Sep-2023 |
Li zeming <zeming@nfschina.com> |
kprobes: Remove unnecessary initial values of variables
ri and sym is assigned first, so it does not need to initialize the assignment.
Link: https://lore.kernel.org/all/20230919012823.7815-1-zemin
kprobes: Remove unnecessary initial values of variables
ri and sym is assigned first, so it does not need to initialize the assignment.
Link: https://lore.kernel.org/all/20230919012823.7815-1-zeming@nfschina.com/
Signed-off-by: Li zeming <zeming@nfschina.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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#
d839a656 |
| 01-Dec-2023 |
JP Kobryn <inwardvessel@gmail.com> |
kprobes: consistent rcu api usage for kretprobe holder
It seems that the pointer-to-kretprobe "rp" within the kretprobe_holder is RCU-managed, based on the (non-rethook) implementation of get_kretpr
kprobes: consistent rcu api usage for kretprobe holder
It seems that the pointer-to-kretprobe "rp" within the kretprobe_holder is RCU-managed, based on the (non-rethook) implementation of get_kretprobe(). The thought behind this patch is to make use of the RCU API where possible when accessing this pointer so that the needed barriers are always in place and to self-document the code.
The __rcu annotation to "rp" allows for sparse RCU checking. Plain writes done to the "rp" pointer are changed to make use of the RCU macro for assignment. For the single read, the implementation of get_kretprobe() is simplified by making use of an RCU macro which accomplishes the same, but note that the log warning text will be more generic.
I did find that there is a difference in assembly generated between the usage of the RCU macros vs without. For example, on arm64, when using rcu_assign_pointer(), the corresponding store instruction is a store-release (STLR) which has an implicit barrier. When normal assignment is done, a regular store (STR) is found. In the macro case, this seems to be a result of rcu_assign_pointer() using smp_store_release() when the value to write is not NULL.
Link: https://lore.kernel.org/all/20231122132058.3359-1-inwardvessel@gmail.com/
Fixes: d741bf41d7c7 ("kprobes: Remove kretprobe hash") Cc: stable@vger.kernel.org Signed-off-by: JP Kobryn <inwardvessel@gmail.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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#
4bbd9345 |
| 17-Oct-2023 |
wuqiang.matt <wuqiang.matt@bytedance.com> |
kprobes: kretprobe scalability improvement
kretprobe is using freelist to manage return-instances, but freelist, as LIFO queue based on singly linked list, scales badly and reduces the overall throu
kprobes: kretprobe scalability improvement
kretprobe is using freelist to manage return-instances, but freelist, as LIFO queue based on singly linked list, scales badly and reduces the overall throughput of kretprobed routines, especially for high contention scenarios.
Here's a typical throughput test of sys_prctl (counts in 10 seconds, measured with perf stat -a -I 10000 -e syscalls:sys_enter_prctl):
OS: Debian 10 X86_64, Linux 6.5rc7 with freelist HW: XEON 8336C x 2, 64 cores/128 threads, DDR4 3200MT/s
1T 2T 4T 8T 16T 24T 24150045 29317964 15446741 12494489 18287272 17708768 32T 48T 64T 72T 96T 128T 16200682 13737658 11645677 11269858 10470118 9931051
This patch introduces objpool to replace freelist. objpool is a high performance queue, which can bring near-linear scalability to kretprobed routines. Tests of kretprobe throughput show the biggest ratio as 159x of original freelist. Here's the result:
1T 2T 4T 8T 16T native: 41186213 82336866 164250978 328662645 658810299 freelist: 24150045 29317964 15446741 12494489 18287272 objpool: 23926730 48010314 96125218 191782984 385091769 32T 48T 64T 96T 128T native: 1330338351 1969957941 2512291791 2615754135 2671040914 freelist: 16200682 13737658 11645677 10470118 9931051 objpool: 764481096 1147149781 1456220214 1502109662 1579015050
Testings on 96-core ARM64 output similarly, but with the biggest ratio up to 448x:
OS: Debian 10 AARCH64, Linux 6.5rc7 HW: Kunpeng-920 96 cores/2 sockets/4 NUMA nodes, DDR4 2933 MT/s
1T 2T 4T 8T 16T native: . 30066096 63569843 126194076 257447289 505800181 freelist: 16152090 11064397 11124068 7215768 5663013 objpool: 13997541 28032100 55726624 110099926 221498787 24T 32T 48T 64T 96T native: 763305277 1015925192 1521075123 2033009392 3021013752 freelist: 5015810 4602893 3766792 3382478 2945292 objpool: 328192025 439439564 668534502 887401381 1319972072
Link: https://lore.kernel.org/all/20231017135654.82270-4-wuqiang.matt@bytedance.com/
Signed-off-by: wuqiang.matt <wuqiang.matt@bytedance.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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#
8865aea0 |
| 25-Jul-2023 |
Ruan Jinjie <ruanjinjie@huawei.com> |
kernel: kprobes: Use struct_size()
Use struct_size() instead of hand-writing it, when allocating a structure with a flex array.
This is less verbose.
Link: https://lore.kernel.org/all/202307251954
kernel: kprobes: Use struct_size()
Use struct_size() instead of hand-writing it, when allocating a structure with a flex array.
This is less verbose.
Link: https://lore.kernel.org/all/20230725195424.3469242-1-ruanjinjie@huawei.com/
Signed-off-by: Ruan Jinjie <ruanjinjie@huawei.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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#
de02f2ac |
| 11-Jul-2023 |
Masami Hiramatsu (Google) <mhiramat@kernel.org> |
kprobes: Prohibit probing on CFI preamble symbol
Do not allow to probe on "__cfi_" or "__pfx_" started symbol, because those are used for CFI and not executed. Probing it will break the CFI.
Link:
kprobes: Prohibit probing on CFI preamble symbol
Do not allow to probe on "__cfi_" or "__pfx_" started symbol, because those are used for CFI and not executed. Probing it will break the CFI.
Link: https://lore.kernel.org/all/168904024679.116016.18089228029322008512.stgit@devnote2/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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#
ed9492df |
| 11-Jul-2023 |
Li zeming <zeming@nfschina.com> |
kernel: kprobes: Remove unnecessary ‘0’ values
it is assigned first, so it does not need to initialize the assignment.
Link: https://lore.kernel.org/all/20230711185353.3218-1-zeming@nfschina.com/
kernel: kprobes: Remove unnecessary ‘0’ values
it is assigned first, so it does not need to initialize the assignment.
Link: https://lore.kernel.org/all/20230711185353.3218-1-zeming@nfschina.com/
Signed-off-by: Li zeming <zeming@nfschina.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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#
e1164787 |
| 04-Jul-2023 |
Li zeming <zeming@nfschina.com> |
kprobes: Remove unnecessary ‘NULL’ values from correct_ret_addr
The 'correct_ret_addr' pointer is always set in the later code, no need to initialize it at definition time.
Link: https://lore.kerne
kprobes: Remove unnecessary ‘NULL’ values from correct_ret_addr
The 'correct_ret_addr' pointer is always set in the later code, no need to initialize it at definition time.
Link: https://lore.kernel.org/all/20230704194359.3124-1-zeming@nfschina.com/
Signed-off-by: Li zeming <zeming@nfschina.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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#
cb16330d |
| 06-Jun-2023 |
Masami Hiramatsu (Google) <mhiramat@kernel.org> |
fprobe: Pass return address to the handlers
Pass return address as 'ret_ip' to the fprobe entry and return handlers so that the fprobe user handler can get the reutrn address without analyzing arch-
fprobe: Pass return address to the handlers
Pass return address as 'ret_ip' to the fprobe entry and return handlers so that the fprobe user handler can get the reutrn address without analyzing arch-dependent pt_regs.
Link: https://lore.kernel.org/all/168507467664.913472.11642316698862778600.stgit@mhiramat.roam.corp.google.com/
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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#
f1c97a1b |
| 20-Feb-2023 |
Yang Jihong <yangjihong1@huawei.com> |
x86/kprobes: Fix arch_check_optimized_kprobe check within optimized_kprobe range
When arch_prepare_optimized_kprobe calculating jump destination address, it copies original instructions from jmp-opt
x86/kprobes: Fix arch_check_optimized_kprobe check within optimized_kprobe range
When arch_prepare_optimized_kprobe calculating jump destination address, it copies original instructions from jmp-optimized kprobe (see __recover_optprobed_insn), and calculated based on length of original instruction.
arch_check_optimized_kprobe does not check KPROBE_FLAG_OPTIMATED when checking whether jmp-optimized kprobe exists. As a result, setup_detour_execution may jump to a range that has been overwritten by jump destination address, resulting in an inval opcode error.
For example, assume that register two kprobes whose addresses are <func+9> and <func+11> in "func" function. The original code of "func" function is as follows:
0xffffffff816cb5e9 <+9>: push %r12 0xffffffff816cb5eb <+11>: xor %r12d,%r12d 0xffffffff816cb5ee <+14>: test %rdi,%rdi 0xffffffff816cb5f1 <+17>: setne %r12b 0xffffffff816cb5f5 <+21>: push %rbp
1.Register the kprobe for <func+11>, assume that is kp1, corresponding optimized_kprobe is op1. After the optimization, "func" code changes to:
0xffffffff816cc079 <+9>: push %r12 0xffffffff816cc07b <+11>: jmp 0xffffffffa0210000 0xffffffff816cc080 <+16>: incl 0xf(%rcx) 0xffffffff816cc083 <+19>: xchg %eax,%ebp 0xffffffff816cc084 <+20>: (bad) 0xffffffff816cc085 <+21>: push %rbp
Now op1->flags == KPROBE_FLAG_OPTIMATED;
2. Register the kprobe for <func+9>, assume that is kp2, corresponding optimized_kprobe is op2.
register_kprobe(kp2) register_aggr_kprobe alloc_aggr_kprobe __prepare_optimized_kprobe arch_prepare_optimized_kprobe __recover_optprobed_insn // copy original bytes from kp1->optinsn.copied_insn, // jump address = <func+14>
3. disable kp1:
disable_kprobe(kp1) __disable_kprobe ... if (p == orig_p || aggr_kprobe_disabled(orig_p)) { ret = disarm_kprobe(orig_p, true) // add op1 in unoptimizing_list, not unoptimized orig_p->flags |= KPROBE_FLAG_DISABLED; // op1->flags == KPROBE_FLAG_OPTIMATED | KPROBE_FLAG_DISABLED ...
4. unregister kp2 __unregister_kprobe_top ... if (!kprobe_disabled(ap) && !kprobes_all_disarmed) { optimize_kprobe(op) ... if (arch_check_optimized_kprobe(op) < 0) // because op1 has KPROBE_FLAG_DISABLED, here not return return; p->kp.flags |= KPROBE_FLAG_OPTIMIZED; // now op2 has KPROBE_FLAG_OPTIMIZED }
"func" code now is:
0xffffffff816cc079 <+9>: int3 0xffffffff816cc07a <+10>: push %rsp 0xffffffff816cc07b <+11>: jmp 0xffffffffa0210000 0xffffffff816cc080 <+16>: incl 0xf(%rcx) 0xffffffff816cc083 <+19>: xchg %eax,%ebp 0xffffffff816cc084 <+20>: (bad) 0xffffffff816cc085 <+21>: push %rbp
5. if call "func", int3 handler call setup_detour_execution:
if (p->flags & KPROBE_FLAG_OPTIMIZED) { ... regs->ip = (unsigned long)op->optinsn.insn + TMPL_END_IDX; ... }
The code for the destination address is
0xffffffffa021072c: push %r12 0xffffffffa021072e: xor %r12d,%r12d 0xffffffffa0210731: jmp 0xffffffff816cb5ee <func+14>
However, <func+14> is not a valid start instruction address. As a result, an error occurs.
Link: https://lore.kernel.org/all/20230216034247.32348-3-yangjihong1@huawei.com/
Fixes: f66c0447cca1 ("kprobes: Set unoptimized flag after unoptimizing code") Signed-off-by: Yang Jihong <yangjihong1@huawei.com> Cc: stable@vger.kernel.org Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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#
868a6fc0 |
| 20-Feb-2023 |
Yang Jihong <yangjihong1@huawei.com> |
x86/kprobes: Fix __recover_optprobed_insn check optimizing logic
Since the following commit:
commit f66c0447cca1 ("kprobes: Set unoptimized flag after unoptimizing code")
modified the update tim
x86/kprobes: Fix __recover_optprobed_insn check optimizing logic
Since the following commit:
commit f66c0447cca1 ("kprobes: Set unoptimized flag after unoptimizing code")
modified the update timing of the KPROBE_FLAG_OPTIMIZED, a optimized_kprobe may be in the optimizing or unoptimizing state when op.kp->flags has KPROBE_FLAG_OPTIMIZED and op->list is not empty.
The __recover_optprobed_insn check logic is incorrect, a kprobe in the unoptimizing state may be incorrectly determined as unoptimizing. As a result, incorrect instructions are copied.
The optprobe_queued_unopt function needs to be exported for invoking in arch directory.
Link: https://lore.kernel.org/all/20230216034247.32348-2-yangjihong1@huawei.com/
Fixes: f66c0447cca1 ("kprobes: Set unoptimized flag after unoptimizing code") Cc: stable@vger.kernel.org Signed-off-by: Yang Jihong <yangjihong1@huawei.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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#
4fbd2f83 |
| 20-Feb-2023 |
Masami Hiramatsu (Google) <mhiramat@kernel.org> |
kprobes: Fix to handle forcibly unoptimized kprobes on freeing_list
Since forcibly unoptimized kprobes will be put on the freeing_list directly in the unoptimize_kprobe(), do_unoptimize_kprobes() mu
kprobes: Fix to handle forcibly unoptimized kprobes on freeing_list
Since forcibly unoptimized kprobes will be put on the freeing_list directly in the unoptimize_kprobe(), do_unoptimize_kprobes() must continue to check the freeing_list even if unoptimizing_list is empty.
This bug can happen if a kprobe is put in an instruction which is in the middle of the jump-replaced instruction sequence of an optprobe, *and* the optprobe is recently unregistered and queued on unoptimizing_list. In this case, the optprobe will be unoptimized forcibly (means immediately) and put it into the freeing_list, expecting the optprobe will be handled in do_unoptimize_kprobe(). But if there is no other optprobes on the unoptimizing_list, current code returns from the do_unoptimize_kprobe() soon and does not handle the optprobe which is on the freeing_list. Then the optprobe will hit the WARN_ON_ONCE() in the do_free_cleaned_kprobes(), because it is not handled in the latter loop of the do_unoptimize_kprobe().
To solve this issue, do not return from do_unoptimize_kprobes() immediately even if unoptimizing_list is empty.
Moreover, this change affects another case. kill_optimized_kprobes() expects kprobe_optimizer() will just free the optprobe on freeing_list. So I changed it to just do list_move() to freeing_list if optprobes are on unoptimizing list. And the do_unoptimize_kprobe() will skip arch_disarm_kprobe() if the probe on freeing_list has gone flag.
Link: https://lore.kernel.org/all/Y8URdIfVr3pq2X8w@xpf.sh.intel.com/ Link: https://lore.kernel.org/all/167448024501.3253718.13037333683110512967.stgit@devnote3/
Fixes: e4add247789e ("kprobes: Fix optimize_kprobe()/unoptimize_kprobe() cancellation logic") Reported-by: Pengfei Xu <pengfei.xu@intel.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: stable@vger.kernel.org Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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#
3b7ddab8 |
| 10-Nov-2022 |
wuqiang <wuqiang.matt@bytedance.com> |
kprobes: kretprobe events missing on 2-core KVM guest
Default value of maxactive is set as num_possible_cpus() for nonpreemptable systems. For a 2-core system, only 2 kretprobe instances would be al
kprobes: kretprobe events missing on 2-core KVM guest
Default value of maxactive is set as num_possible_cpus() for nonpreemptable systems. For a 2-core system, only 2 kretprobe instances would be allocated in default, then these 2 instances for execve kretprobe are very likely to be used up with a pipelined command.
Here's the testcase: a shell script was added to crontab, and the content of the script is:
#!/bin/sh do_something_magic `tr -dc a-z < /dev/urandom | head -c 10`
cron will trigger a series of program executions (4 times every hour). Then events loss would be noticed normally after 3-4 hours of testings.
The issue is caused by a burst of series of execve requests. The best number of kretprobe instances could be different case by case, and should be user's duty to determine, but num_possible_cpus() as the default value is inadequate especially for systems with small number of cpus.
This patch enables the logic for preemption as default, thus increases the minimum of maxactive to 10 for nonpreemptable systems.
Link: https://lore.kernel.org/all/20221110081502.492289-1-wuqiang.matt@bytedance.com/
Signed-off-by: wuqiang <wuqiang.matt@bytedance.com> Reviewed-by: Solar Designer <solar@openwall.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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#
0c76ef3f |
| 26-Nov-2022 |
Li Huafei <lihuafei1@huawei.com> |
kprobes: Fix check for probe enabled in kill_kprobe()
In kill_kprobe(), the check whether disarm_kprobe_ftrace() needs to be called always fails. This is because before that we set the KPROBE_FLAG_G
kprobes: Fix check for probe enabled in kill_kprobe()
In kill_kprobe(), the check whether disarm_kprobe_ftrace() needs to be called always fails. This is because before that we set the KPROBE_FLAG_GONE flag for kprobe so that "!kprobe_disabled(p)" is always false.
The disarm_kprobe_ftrace() call introduced by commit:
0cb2f1372baa ("kprobes: Fix NULL pointer dereference at kprobe_ftrace_handler")
to fix the NULL pointer reference problem. When the probe is enabled, if we do not disarm it, this problem still exists.
Fix it by putting the probe enabled check before setting the KPROBE_FLAG_GONE flag.
Link: https://lore.kernel.org/all/20221126114316.201857-1-lihuafei1@huawei.com/
Fixes: 3031313eb3d54 ("kprobes: Fix to check probe enabled before disarm_kprobe_ftrace()") Signed-off-by: Li Huafei <lihuafei1@huawei.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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#
5dd7caf0 |
| 18-Nov-2022 |
Li Huafei <lihuafei1@huawei.com> |
kprobes: Skip clearing aggrprobe's post_handler in kprobe-on-ftrace case
In __unregister_kprobe_top(), if the currently unregistered probe has post_handler but other child probes of the aggrprobe do
kprobes: Skip clearing aggrprobe's post_handler in kprobe-on-ftrace case
In __unregister_kprobe_top(), if the currently unregistered probe has post_handler but other child probes of the aggrprobe do not have post_handler, the post_handler of the aggrprobe is cleared. If this is a ftrace-based probe, there is a problem. In later calls to disarm_kprobe(), we will use kprobe_ftrace_ops because post_handler is NULL. But we're armed with kprobe_ipmodify_ops. This triggers a WARN in __disarm_kprobe_ftrace() and may even cause use-after-free:
Failed to disarm kprobe-ftrace at kernel_clone+0x0/0x3c0 (error -2) WARNING: CPU: 5 PID: 137 at kernel/kprobes.c:1135 __disarm_kprobe_ftrace.isra.21+0xcf/0xe0 Modules linked in: testKprobe_007(-) CPU: 5 PID: 137 Comm: rmmod Not tainted 6.1.0-rc4-dirty #18 [...] Call Trace: <TASK> __disable_kprobe+0xcd/0xe0 __unregister_kprobe_top+0x12/0x150 ? mutex_lock+0xe/0x30 unregister_kprobes.part.23+0x31/0xa0 unregister_kprobe+0x32/0x40 __x64_sys_delete_module+0x15e/0x260 ? do_user_addr_fault+0x2cd/0x6b0 do_syscall_64+0x3a/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd [...]
For the kprobe-on-ftrace case, we keep the post_handler setting to identify this aggrprobe armed with kprobe_ipmodify_ops. This way we can disarm it correctly.
Link: https://lore.kernel.org/all/20221112070000.35299-1-lihuafei1@huawei.com/
Fixes: 0bc11ed5ab60 ("kprobes: Allow kprobes coexist with livepatch") Reported-by: Zhao Gongyi <zhaogongyi@huawei.com> Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Li Huafei <lihuafei1@huawei.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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#
4a6f316d |
| 03-Nov-2022 |
Li Qiang <liq3ea@163.com> |
kprobe: reverse kp->flags when arm_kprobe failed
In aggregate kprobe case, when arm_kprobe failed, we need set the kp->flags with KPROBE_FLAG_DISABLED again. If not, the 'kp' kprobe will been consid
kprobe: reverse kp->flags when arm_kprobe failed
In aggregate kprobe case, when arm_kprobe failed, we need set the kp->flags with KPROBE_FLAG_DISABLED again. If not, the 'kp' kprobe will been considered as enabled but it actually not enabled.
Link: https://lore.kernel.org/all/20220902155820.34755-1-liq3ea@163.com/
Fixes: 12310e343755 ("kprobes: Propagate error from arm_kprobe_ftrace()") Cc: stable@vger.kernel.org Signed-off-by: Li Qiang <liq3ea@163.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
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#
bf7a87f1 |
| 26-Sep-2022 |
Jiri Olsa <jolsa@kernel.org> |
kprobes: Add new KPROBE_FLAG_ON_FUNC_ENTRY kprobe flag
Adding KPROBE_FLAG_ON_FUNC_ENTRY kprobe flag to indicate that attach address is on function entry. This is used in following changes in get_fun
kprobes: Add new KPROBE_FLAG_ON_FUNC_ENTRY kprobe flag
Adding KPROBE_FLAG_ON_FUNC_ENTRY kprobe flag to indicate that attach address is on function entry. This is used in following changes in get_func_ip helper to return correct function address.
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20220926153340.1621984-2-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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1efda38d |
| 07-Sep-2022 |
Christian A. Ehrhardt <lk@c--e.de> |
kprobes: Prohibit probes in gate area
The system call gate area counts as kernel text but trying to install a kprobe in this area fails with an Oops later on. To fix this explicitly disallow the gat
kprobes: Prohibit probes in gate area
The system call gate area counts as kernel text but trying to install a kprobe in this area fails with an Oops later on. To fix this explicitly disallow the gate area for kprobes.
Found by syzkaller with the following reproducer: perf_event_open$cgroup(&(0x7f00000001c0)={0x6, 0x80, 0x0, 0x0, 0x0, 0x0, 0x80ffff, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, @perf_config_ext={0x0, 0xffffffffff600000}}, 0xffffffffffffffff, 0x0, 0xffffffffffffffff, 0x0)
Sample report: BUG: unable to handle page fault for address: fffffbfff3ac6000 PGD 6dfcb067 P4D 6dfcb067 PUD 6df8f067 PMD 6de4d067 PTE 0 Oops: 0000 [#1] PREEMPT SMP KASAN NOPTI CPU: 0 PID: 21978 Comm: syz-executor.2 Not tainted 6.0.0-rc3-00363-g7726d4c3e60b-dirty #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 RIP: 0010:__insn_get_emulate_prefix arch/x86/lib/insn.c:91 [inline] RIP: 0010:insn_get_emulate_prefix arch/x86/lib/insn.c:106 [inline] RIP: 0010:insn_get_prefixes.part.0+0xa8/0x1110 arch/x86/lib/insn.c:134 Code: 49 be 00 00 00 00 00 fc ff df 48 8b 40 60 48 89 44 24 08 e9 81 00 00 00 e8 e5 4b 39 ff 4c 89 fa 4c 89 f9 48 c1 ea 03 83 e1 07 <42> 0f b6 14 32 38 ca 7f 08 84 d2 0f 85 06 10 00 00 48 89 d8 48 89 RSP: 0018:ffffc900088bf860 EFLAGS: 00010246 RAX: 0000000000040000 RBX: ffffffff9b9bebc0 RCX: 0000000000000000 RDX: 1ffffffff3ac6000 RSI: ffffc90002d82000 RDI: ffffc900088bf9e8 RBP: ffffffff9d630001 R08: 0000000000000000 R09: ffffc900088bf9e8 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001 R13: ffffffff9d630000 R14: dffffc0000000000 R15: ffffffff9d630000 FS: 00007f63eef63640(0000) GS:ffff88806d000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffbfff3ac6000 CR3: 0000000029d90005 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: <TASK> insn_get_prefixes arch/x86/lib/insn.c:131 [inline] insn_get_opcode arch/x86/lib/insn.c:272 [inline] insn_get_modrm+0x64a/0x7b0 arch/x86/lib/insn.c:343 insn_get_sib+0x29a/0x330 arch/x86/lib/insn.c:421 insn_get_displacement+0x350/0x6b0 arch/x86/lib/insn.c:464 insn_get_immediate arch/x86/lib/insn.c:632 [inline] insn_get_length arch/x86/lib/insn.c:707 [inline] insn_decode+0x43a/0x490 arch/x86/lib/insn.c:747 can_probe+0xfc/0x1d0 arch/x86/kernel/kprobes/core.c:282 arch_prepare_kprobe+0x79/0x1c0 arch/x86/kernel/kprobes/core.c:739 prepare_kprobe kernel/kprobes.c:1160 [inline] register_kprobe kernel/kprobes.c:1641 [inline] register_kprobe+0xb6e/0x1690 kernel/kprobes.c:1603 __register_trace_kprobe kernel/trace/trace_kprobe.c:509 [inline] __register_trace_kprobe+0x26a/0x2d0 kernel/trace/trace_kprobe.c:477 create_local_trace_kprobe+0x1f7/0x350 kernel/trace/trace_kprobe.c:1833 perf_kprobe_init+0x18c/0x280 kernel/trace/trace_event_perf.c:271 perf_kprobe_event_init+0xf8/0x1c0 kernel/events/core.c:9888 perf_try_init_event+0x12d/0x570 kernel/events/core.c:11261 perf_init_event kernel/events/core.c:11325 [inline] perf_event_alloc.part.0+0xf7f/0x36a0 kernel/events/core.c:11619 perf_event_alloc kernel/events/core.c:12059 [inline] __do_sys_perf_event_open+0x4a8/0x2a00 kernel/events/core.c:12157 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f63ef7efaed Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f63eef63028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007f63ef90ff80 RCX: 00007f63ef7efaed RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 00000000200001c0 RBP: 00007f63ef86019c R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000002 R14: 00007f63ef90ff80 R15: 00007f63eef43000 </TASK> Modules linked in: CR2: fffffbfff3ac6000 ---[ end trace 0000000000000000 ]--- RIP: 0010:__insn_get_emulate_prefix arch/x86/lib/insn.c:91 [inline] RIP: 0010:insn_get_emulate_prefix arch/x86/lib/insn.c:106 [inline] RIP: 0010:insn_get_prefixes.part.0+0xa8/0x1110 arch/x86/lib/insn.c:134 Code: 49 be 00 00 00 00 00 fc ff df 48 8b 40 60 48 89 44 24 08 e9 81 00 00 00 e8 e5 4b 39 ff 4c 89 fa 4c 89 f9 48 c1 ea 03 83 e1 07 <42> 0f b6 14 32 38 ca 7f 08 84 d2 0f 85 06 10 00 00 48 89 d8 48 89 RSP: 0018:ffffc900088bf860 EFLAGS: 00010246 RAX: 0000000000040000 RBX: ffffffff9b9bebc0 RCX: 0000000000000000 RDX: 1ffffffff3ac6000 RSI: ffffc90002d82000 RDI: ffffc900088bf9e8 RBP: ffffffff9d630001 R08: 0000000000000000 R09: ffffc900088bf9e8 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001 R13: ffffffff9d630000 R14: dffffc0000000000 R15: ffffffff9d630000 FS: 00007f63eef63640(0000) GS:ffff88806d000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffbfff3ac6000 CR3: 0000000029d90005 CR4: 0000000000770ef0 PKRU: 55555554 ==================================================================
Link: https://lkml.kernel.org/r/20220907200917.654103-1-lk@c--e.de
cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> cc: "David S. Miller" <davem@davemloft.net> Cc: stable@vger.kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Christian A. Ehrhardt <lk@c--e.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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9c80e799 |
| 13-Aug-2022 |
Kuniyuki Iwashima <kuniyu@amazon.com> |
kprobes: don't call disarm_kprobe() for disabled kprobes
The assumption in __disable_kprobe() is wrong, and it could try to disarm an already disarmed kprobe and fire the WARN_ONCE() below. [0] We
kprobes: don't call disarm_kprobe() for disabled kprobes
The assumption in __disable_kprobe() is wrong, and it could try to disarm an already disarmed kprobe and fire the WARN_ONCE() below. [0] We can easily reproduce this issue.
1. Write 0 to /sys/kernel/debug/kprobes/enabled.
# echo 0 > /sys/kernel/debug/kprobes/enabled
2. Run execsnoop. At this time, one kprobe is disabled.
# /usr/share/bcc/tools/execsnoop & [1] 2460 PCOMM PID PPID RET ARGS
# cat /sys/kernel/debug/kprobes/list ffffffff91345650 r __x64_sys_execve+0x0 [FTRACE] ffffffff91345650 k __x64_sys_execve+0x0 [DISABLED][FTRACE]
3. Write 1 to /sys/kernel/debug/kprobes/enabled, which changes kprobes_all_disarmed to false but does not arm the disabled kprobe.
# echo 1 > /sys/kernel/debug/kprobes/enabled
# cat /sys/kernel/debug/kprobes/list ffffffff91345650 r __x64_sys_execve+0x0 [FTRACE] ffffffff91345650 k __x64_sys_execve+0x0 [DISABLED][FTRACE]
4. Kill execsnoop, when __disable_kprobe() calls disarm_kprobe() for the disabled kprobe and hits the WARN_ONCE() in __disarm_kprobe_ftrace().
# fg /usr/share/bcc/tools/execsnoop ^C
Actually, WARN_ONCE() is fired twice, and __unregister_kprobe_top() misses some cleanups and leaves the aggregated kprobe in the hash table. Then, __unregister_trace_kprobe() initialises tk->rp.kp.list and creates an infinite loop like this.
aggregated kprobe.list -> kprobe.list -. ^ | '.__.'
In this situation, these commands fall into the infinite loop and result in RCU stall or soft lockup.
cat /sys/kernel/debug/kprobes/list : show_kprobe_addr() enters into the infinite loop with RCU.
/usr/share/bcc/tools/execsnoop : warn_kprobe_rereg() holds kprobe_mutex, and __get_valid_kprobe() is stuck in the loop.
To avoid the issue, make sure we don't call disarm_kprobe() for disabled kprobes.
[0] Failed to disarm kprobe-ftrace at __x64_sys_execve+0x0/0x40 (error -2) WARNING: CPU: 6 PID: 2460 at kernel/kprobes.c:1130 __disarm_kprobe_ftrace.isra.19 (kernel/kprobes.c:1129) Modules linked in: ena CPU: 6 PID: 2460 Comm: execsnoop Not tainted 5.19.0+ #28 Hardware name: Amazon EC2 c5.2xlarge/, BIOS 1.0 10/16/2017 RIP: 0010:__disarm_kprobe_ftrace.isra.19 (kernel/kprobes.c:1129) Code: 24 8b 02 eb c1 80 3d c4 83 f2 01 00 75 d4 48 8b 75 00 89 c2 48 c7 c7 90 fa 0f 92 89 04 24 c6 05 ab 83 01 e8 e4 94 f0 ff <0f> 0b 8b 04 24 eb b1 89 c6 48 c7 c7 60 fa 0f 92 89 04 24 e8 cc 94 RSP: 0018:ffff9e6ec154bd98 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffffffff930f7b00 RCX: 0000000000000001 RDX: 0000000080000001 RSI: ffffffff921461c5 RDI: 00000000ffffffff RBP: ffff89c504286da8 R08: 0000000000000000 R09: c0000000fffeffff R10: 0000000000000000 R11: ffff9e6ec154bc28 R12: ffff89c502394e40 R13: ffff89c502394c00 R14: ffff9e6ec154bc00 R15: 0000000000000000 FS: 00007fe800398740(0000) GS:ffff89c812d80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c00057f010 CR3: 0000000103b54006 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> __disable_kprobe (kernel/kprobes.c:1716) disable_kprobe (kernel/kprobes.c:2392) __disable_trace_kprobe (kernel/trace/trace_kprobe.c:340) disable_trace_kprobe (kernel/trace/trace_kprobe.c:429) perf_trace_event_unreg.isra.2 (./include/linux/tracepoint.h:93 kernel/trace/trace_event_perf.c:168) perf_kprobe_destroy (kernel/trace/trace_event_perf.c:295) _free_event (kernel/events/core.c:4971) perf_event_release_kernel (kernel/events/core.c:5176) perf_release (kernel/events/core.c:5186) __fput (fs/file_table.c:321) task_work_run (./include/linux/sched.h:2056 (discriminator 1) kernel/task_work.c:179 (discriminator 1)) exit_to_user_mode_prepare (./include/linux/resume_user_mode.h:49 kernel/entry/common.c:169 kernel/entry/common.c:201) syscall_exit_to_user_mode (./arch/x86/include/asm/jump_label.h:55 ./arch/x86/include/asm/nospec-branch.h:384 ./arch/x86/include/asm/entry-common.h:94 kernel/entry/common.c:133 kernel/entry/common.c:296) do_syscall_64 (arch/x86/entry/common.c:87) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) RIP: 0033:0x7fe7ff210654 Code: 15 79 89 20 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb be 0f 1f 00 8b 05 9a cd 20 00 48 63 ff 85 c0 75 11 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 3a f3 c3 48 83 ec 18 48 89 7c 24 08 e8 34 fc RSP: 002b:00007ffdbd1d3538 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000008 RCX: 00007fe7ff210654 RDX: 0000000000000000 RSI: 0000000000002401 RDI: 0000000000000008 RBP: 0000000000000000 R08: 94ae31d6fda838a4 R0900007fe8001c9d30 R10: 00007ffdbd1d34b0 R11: 0000000000000246 R12: 00007ffdbd1d3600 R13: 0000000000000000 R14: fffffffffffffffc R15: 00007ffdbd1d3560 </TASK>
Link: https://lkml.kernel.org/r/20220813020509.90805-1-kuniyu@amazon.com Fixes: 69d54b916d83 ("kprobes: makes kprobes/enabled works correctly for optimized kprobes.") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reported-by: Ayushman Dutta <ayudutta@amazon.com> Cc: "Naveen N. Rao" <naveen.n.rao@linux.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Cc: Kuniyuki Iwashima <kuniyu@amazon.com> Cc: Kuniyuki Iwashima <kuni1840@gmail.com> Cc: Ayushman Dutta <ayudutta@amazon.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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28f6c37a |
| 01-Aug-2022 |
Chen Zhongjin <chenzhongjin@huawei.com> |
kprobes: Forbid probing on trampoline and BPF code areas
kernel_text_address() treats ftrace_trampoline, kprobe_insn_slot and bpf_text_address as valid kprobe addresses - which is not ideal.
These
kprobes: Forbid probing on trampoline and BPF code areas
kernel_text_address() treats ftrace_trampoline, kprobe_insn_slot and bpf_text_address as valid kprobe addresses - which is not ideal.
These text areas are removable and changeable without any notification to kprobes, and probing on them can trigger unexpected behavior:
https://lkml.org/lkml/2022/7/26/1148
Considering that jump_label and static_call text are already forbiden to probe, kernel_text_address() should be replaced with core_kernel_text() and is_module_text_address() to check other text areas which are unsafe to kprobe.
[ mingo: Rewrote the changelog. ]
Fixes: 5b485629ba0d ("kprobes, extable: Identify kprobes trampolines as kernel text area") Fixes: 74451e66d516 ("bpf: make jited programs visible in traces") Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Link: https://lore.kernel.org/r/20220801033719.228248-1-chenzhongjin@huawei.com
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43994049 |
| 04-May-2022 |
Masami Hiramatsu <mhiramat@kernel.org> |
kprobes: Fix build errors with CONFIG_KRETPROBES=n
Max Filippov reported:
When building kernel with CONFIG_KRETPROBES=n kernel/kprobes.c compilation fails with the following messages:
kernel/kpr
kprobes: Fix build errors with CONFIG_KRETPROBES=n
Max Filippov reported:
When building kernel with CONFIG_KRETPROBES=n kernel/kprobes.c compilation fails with the following messages:
kernel/kprobes.c: In function ‘recycle_rp_inst’: kernel/kprobes.c:1273:32: error: implicit declaration of function ‘get_kretprobe’
kernel/kprobes.c: In function ‘kprobe_flush_task’: kernel/kprobes.c:1299:35: error: ‘struct task_struct’ has no member named ‘kretprobe_instances’
This came from the commit d741bf41d7c7 ("kprobes: Remove kretprobe hash") which introduced get_kretprobe() and kretprobe_instances member in task_struct when CONFIG_KRETPROBES=y, but did not make recycle_rp_inst() and kprobe_flush_task() depending on CONFIG_KRETPORBES.
Since those functions are only used for kretprobe, move those functions into #ifdef CONFIG_KRETPROBE area.
Link: https://lkml.kernel.org/r/165163539094.74407.3838114721073251225.stgit@devnote2
Reported-by: Max Filippov <jcmvbkbc@gmail.com> Fixes: d741bf41d7c7 ("kprobes: Remove kretprobe hash") Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: "David S . Miller" <davem@davemloft.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Tested-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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1d661ed5 |
| 22-Apr-2022 |
Adam Zabrocki <pi3@pi3.com.pl> |
kprobes: Fix KRETPROBES when CONFIG_KRETPROBE_ON_RETHOOK is set
The recent kernel change in 73f9b911faa7 ("kprobes: Use rethook for kretprobe if possible"), introduced a potential NULL pointer deref
kprobes: Fix KRETPROBES when CONFIG_KRETPROBE_ON_RETHOOK is set
The recent kernel change in 73f9b911faa7 ("kprobes: Use rethook for kretprobe if possible"), introduced a potential NULL pointer dereference bug in the KRETPROBE mechanism. The official Kprobes documentation defines that "Any or all handlers can be NULL". Unfortunately, there is a missing return handler verification to fulfill these requirements and can result in a NULL pointer dereference bug.
This patch adds such verification in kretprobe_rethook_handler() function.
Fixes: 73f9b911faa7 ("kprobes: Use rethook for kretprobe if possible") Signed-off-by: Adam Zabrocki <pi3@pi3.com.pl> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com> Cc: Anil S. Keshavamurthy <anil.s.keshavamurthy@intel.com> Link: https://lore.kernel.org/bpf/20220422164027.GA7862@pi3.com.pl
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73f9b911 |
| 26-Mar-2022 |
Masami Hiramatsu <mhiramat@kernel.org> |
kprobes: Use rethook for kretprobe if possible
Use rethook for kretprobe function return hooking if the arch sets CONFIG_HAVE_RETHOOK=y. In this case, CONFIG_KRETPROBE_ON_RETHOOK is set to 'y' autom
kprobes: Use rethook for kretprobe if possible
Use rethook for kretprobe function return hooking if the arch sets CONFIG_HAVE_RETHOOK=y. In this case, CONFIG_KRETPROBE_ON_RETHOOK is set to 'y' automatically, and the kretprobe internal data fields switches to use rethook. If not, it continues to use kretprobe specific function return hooks.
Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/164826162556.2455864.12255833167233452047.stgit@devnote2
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cc66bb91 |
| 08-Mar-2022 |
Peter Zijlstra <peterz@infradead.org> |
x86/ibt,kprobes: Cure sym+0 equals fentry woes
In order to allow kprobes to skip the ENDBR instructions at sym+0 for X86_KERNEL_IBT builds, change _kprobe_addr() to take an architecture callback to
x86/ibt,kprobes: Cure sym+0 equals fentry woes
In order to allow kprobes to skip the ENDBR instructions at sym+0 for X86_KERNEL_IBT builds, change _kprobe_addr() to take an architecture callback to inspect the function at hand and modify the offset if needed.
This streamlines the existing interface to cover more cases and require less hooks. Once PowerPC gets fully converted there will only be the one arch hook.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.405947704@infradead.org
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aebfd125 |
| 08-Mar-2022 |
Peter Zijlstra <peterz@infradead.org> |
x86/ibt,ftrace: Search for __fentry__ location
Currently a lot of ftrace code assumes __fentry__ is at sym+0. However with Intel IBT enabled the first instruction of a function will most likely be E
x86/ibt,ftrace: Search for __fentry__ location
Currently a lot of ftrace code assumes __fentry__ is at sym+0. However with Intel IBT enabled the first instruction of a function will most likely be ENDBR.
Change ftrace_location() to not only return the __fentry__ location when called for the __fentry__ location, but also when called for the sym+0 location.
Then audit/update all callsites of this function to consistently use these new semantics.
Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lore.kernel.org/r/20220308154318.227581603@infradead.org
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