#
493c1822 |
| 08-Jun-2022 |
Frederic Weisbecker <frederic@kernel.org> |
context_tracking: Take NMI eqs entrypoints over RCU
The RCU dynticks counter is going to be merged into the context tracking subsystem. Prepare with moving the NMI extended quiescent states entrypoi
context_tracking: Take NMI eqs entrypoints over RCU
The RCU dynticks counter is going to be merged into the context tracking subsystem. Prepare with moving the NMI extended quiescent states entrypoints to context tracking. For now those are dumb redirection to existing RCU calls.
Acked-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Neeraj Upadhyay <quic_neeraju@quicinc.com> Cc: Uladzislau Rezki <uladzislau.rezki@sony.com> Cc: Joel Fernandes <joel@joelfernandes.org> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Nicolas Saenz Julienne <nsaenz@kernel.org> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Xiongfeng Wang <wangxiongfeng2@huawei.com> Cc: Yu Liao <liaoyu15@huawei.com> Cc: Phil Auld <pauld@redhat.com> Cc: Paul Gortmaker<paul.gortmaker@windriver.com> Cc: Alex Belits <abelits@marvell.com> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Reviewed-by: Nicolas Saenz Julienne <nsaenzju@redhat.com> Tested-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
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#
b6491339 |
| 15-Feb-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
lkdtm: Really write into kernel text in WRITE_KERN
WRITE_KERN is supposed to overwrite some kernel text, namely do_overwritten() function.
But at the time being it overwrites do_overwritten() funct
lkdtm: Really write into kernel text in WRITE_KERN
WRITE_KERN is supposed to overwrite some kernel text, namely do_overwritten() function.
But at the time being it overwrites do_overwritten() function descriptor, not function text.
Fix it by dereferencing the function descriptor to obtain function text pointer. Export dereference_function_descriptor() for when LKDTM is built as a module.
And make do_overwritten() noinline so that it is really do_overwritten() which is called by lkdtm_WRITE_KERN().
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/31e58eaffb5bc51c07d8d4891d1982100ade8cfc.1644928018.git.christophe.leroy@csgroup.eu
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#
e1478d8e |
| 15-Feb-2022 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
asm-generic: Refactor dereference_[kernel]_function_descriptor()
dereference_function_descriptor() and dereference_kernel_function_descriptor() are identical on the three architectures implementing
asm-generic: Refactor dereference_[kernel]_function_descriptor()
dereference_function_descriptor() and dereference_kernel_function_descriptor() are identical on the three architectures implementing them.
Make them common and put them out-of-line in kernel/extable.c which is one of the users and has similar type of functions.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Helge Deller <deller@gmx.de> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/449db09b2eba57f4ab05f80102a67d8675bc8bcd.1644928018.git.christophe.leroy@csgroup.eu
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#
808b6456 |
| 09-Nov-2021 |
Kefeng Wang <wangkefeng.wang@huawei.com> |
extable: use is_kernel_text() helper
The core_kernel_text() should check the gate area, as it is part of kernel text range, use is_kernel_text() in core_kernel_text().
Link: https://lkml.kernel.org
extable: use is_kernel_text() helper
The core_kernel_text() should check the gate area, as it is part of kernel text range, use is_kernel_text() in core_kernel_text().
Link: https://lkml.kernel.org/r/20210930071143.63410-9-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Alexander Potapenko <glider@google.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Paul Mackerras <paulus@samba.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
b9ad8fe7 |
| 09-Nov-2021 |
Kefeng Wang <wangkefeng.wang@huawei.com> |
sections: move is_kernel_inittext() into sections.h
The is_kernel_inittext() and init_kernel_text() are with same functionality, let's just keep is_kernel_inittext() and move it into sections.h, the
sections: move is_kernel_inittext() into sections.h
The is_kernel_inittext() and init_kernel_text() are with same functionality, let's just keep is_kernel_inittext() and move it into sections.h, then update all the callers.
Link: https://lkml.kernel.org/r/20210930071143.63410-5-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Alexander Potapenko <glider@google.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: "David S. Miller" <davem@davemloft.net> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Paul Mackerras <paulus@samba.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
a20deb3a |
| 09-Nov-2021 |
Kefeng Wang <wangkefeng.wang@huawei.com> |
sections: move and rename core_kernel_data() to is_kernel_core_data()
Move core_kernel_data() into sections.h and rename it to is_kernel_core_data(), also make it return bool value, then update all
sections: move and rename core_kernel_data() to is_kernel_core_data()
Move core_kernel_data() into sections.h and rename it to is_kernel_core_data(), also make it return bool value, then update all the callers.
Link: https://lkml.kernel.org/r/20210930071143.63410-4-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexander Potapenko <glider@google.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Paul Mackerras <paulus@samba.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Richard Henderson <rth@twiddle.net> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
d2635f20 |
| 05-Nov-2021 |
Christophe Leroy <christophe.leroy@csgroup.eu> |
mm: create a new system state and fix core_kernel_text()
core_kernel_text() considers that until system_state in at least SYSTEM_RUNNING, init memory is valid.
But init memory is freed a few lines
mm: create a new system state and fix core_kernel_text()
core_kernel_text() considers that until system_state in at least SYSTEM_RUNNING, init memory is valid.
But init memory is freed a few lines before setting SYSTEM_RUNNING, so we have a small period of time when core_kernel_text() is wrong.
Create an intermediate system state called SYSTEM_FREEING_INIT that is set before starting freeing init memory, and use it in core_kernel_text() to report init memory invalid earlier.
Link: https://lkml.kernel.org/r/9ecfdee7dd4d741d172cb93ff1d87f1c58127c9a.1633001016.git.christophe.leroy@csgroup.eu Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
63174f61 |
| 07-Apr-2020 |
Nathan Chancellor <natechancellor@gmail.com> |
kernel/extable.c: use address-of operator on section symbols
Clang warns:
../kernel/extable.c:37:52: warning: array comparison always evaluates to a constant [-Wtautological-compare] if (ma
kernel/extable.c: use address-of operator on section symbols
Clang warns:
../kernel/extable.c:37:52: warning: array comparison always evaluates to a constant [-Wtautological-compare] if (main_extable_sort_needed && __stop___ex_table > __start___ex_table) { ^ 1 warning generated.
These are not true arrays, they are linker defined symbols, which are just addresses. Using the address of operator silences the warning and does not change the resulting assembly with either clang/ld.lld or gcc/ld (tested with diff + objdump -Dr).
Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Link: https://github.com/ClangBuiltLinux/linux/issues/892 Link: http://lkml.kernel.org/r/20200219202036.45702-1-natechancellor@gmail.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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#
7ac88eba |
| 12-Mar-2020 |
Jiri Olsa <jolsa@kernel.org> |
bpf: Remove bpf_image tree
Now that we have all the objects (bpf_prog, bpf_trampoline, bpf_dispatcher) linked in bpf_tree, there's no need to have separate bpf_image tree for images.
Reverting the
bpf: Remove bpf_image tree
Now that we have all the objects (bpf_prog, bpf_trampoline, bpf_dispatcher) linked in bpf_tree, there's no need to have separate bpf_image tree for images.
Reverting the bpf_image tree together with struct bpf_image, because it's no longer needed.
Also removing bpf_image_alloc function and adding the original bpf_jit_alloc_exec_page interface instead.
The kernel_text_address function can now rely only on is_bpf_text_address, because it checks the bpf_tree that contains all the objects.
Keeping bpf_image_ksym_add and bpf_image_ksym_del because they are useful wrappers with perf's ksymbol interface calls.
Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200312195610.346362-13-jolsa@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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#
e9b4e606 |
| 23-Jan-2020 |
Jiri Olsa <jolsa@kernel.org> |
bpf: Allow to resolve bpf trampoline and dispatcher in unwind
When unwinding the stack we need to identify each address to successfully continue. Adding latch tree to keep trampolines for quick look
bpf: Allow to resolve bpf trampoline and dispatcher in unwind
When unwinding the stack we need to identify each address to successfully continue. Adding latch tree to keep trampolines for quick lookup during the unwind.
The patch uses first 48 bytes for latch tree node, leaving 4048 bytes from the rest of the page for trampoline or dispatcher generated code.
It's still enough not to affect trampoline and dispatcher progs maximum counts.
Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200123161508.915203-3-jolsa@kernel.org
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#
3dec541b |
| 16-Oct-2019 |
Alexei Starovoitov <ast@kernel.org> |
bpf: Add support for BTF pointers to x86 JIT
Pointer to BTF object is a pointer to kernel object or NULL. Such pointers can only be used by BPF_LDX instructions. The verifier changed their opcode fr
bpf: Add support for BTF pointers to x86 JIT
Pointer to BTF object is a pointer to kernel object or NULL. Such pointers can only be used by BPF_LDX instructions. The verifier changed their opcode from LDX|MEM|size to LDX|PROBE_MEM|size to make JITing easier. The number of entries in extable is the number of BPF_LDX insns that access kernel memory via "pointer to BTF type". Only these load instructions can fault. Since x86 extable is relative it has to be allocated in the same memory region as JITed code. Allocate it prior to last pass of JITing and let the last pass populate it. Pointer to extable in bpf_prog_aux is necessary to make page fault handling fast. Page fault handling is done in two steps: 1. bpf_prog_kallsyms_find() finds BPF program that page faulted. It's done by walking rb tree. 2. then extable for given bpf program is binary searched. This process is similar to how page faulting is done for kernel modules. The exception handler skips over faulting x86 instruction and initializes destination register with zero. This mimics exact behavior of bpf_probe_read (when probe_kernel_read faults dest is zeroed).
JITs for other architectures can add support in similar way. Until then they will reject unknown opcode and fallback to interpreter.
Since extable should be aligned and placed near JITed code make bpf_jit_binary_alloc() return 4 byte aligned image offset, so that extable aligning formula in bpf_int_jit_compile() doesn't need to rely on internal implementation of bpf_jit_binary_alloc(). On x86 gcc defaults to 16-byte alignment for regular kernel functions due to better performance. JITed code may be aligned to 16 in the future, but it will use 4 in the meantime.
Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191016032505.2089704-10-ast@kernel.org
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#
49ec9177 |
| 20-Aug-2019 |
Santosh Sivaraj <santosh@fossix.org> |
extable: Add function to search only kernel exception table
Certain architecture specific operating modes (e.g., in powerpc machine check handler that is unable to access vmalloc memory), the search
extable: Add function to search only kernel exception table
Certain architecture specific operating modes (e.g., in powerpc machine check handler that is unable to access vmalloc memory), the search_exception_tables cannot be called because it also searches the module exception tables if entry is not found in the kernel exception table.
Signed-off-by: Santosh Sivaraj <santosh@fossix.org> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190820081352.8641-5-santosh@fossix.org
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#
1a59d1b8 |
| 27-May-2019 |
Thomas Gleixner <tglx@linutronix.de> |
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify it under the terms of th
treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 1334 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
9fbcc57a |
| 20-Feb-2018 |
Josh Poimboeuf <jpoimboe@redhat.com> |
extable: Make init_kernel_text() global
Convert init_kernel_text() to a global function and use it in a few places instead of manually comparing _sinittext and _einittext.
Note that kallsyms.h has
extable: Make init_kernel_text() global
Convert init_kernel_text() to a global function and use it in a few places instead of manually comparing _sinittext and _einittext.
Note that kallsyms.h has a very similar function called is_kernel_inittext(), but its end check is inclusive. I'm not sure whether that's intentional behavior, so I didn't touch it.
Suggested-by: Jason Baron <jbaron@akamai.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Borislav Petkov <bp@suse.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/4335d02be8d45ca7d265d2f174251d0b7ee6c5fd.1519051220.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
e846d139 |
| 02-Nov-2017 |
Zhou Chengming <zhouchengming1@huawei.com> |
kprobes, x86/alternatives: Use text_mutex to protect smp_alt_modules
We use alternatives_text_reserved() to check if the address is in the fixed pieces of alternative reserved, but the problem is th
kprobes, x86/alternatives: Use text_mutex to protect smp_alt_modules
We use alternatives_text_reserved() to check if the address is in the fixed pieces of alternative reserved, but the problem is that we don't hold the smp_alt mutex when call this function. So the list traversal may encounter a deleted list_head if another path is doing alternatives_smp_module_del().
One solution is that we can hold smp_alt mutex before call this function, but the difficult point is that the callers of this functions, arch_prepare_kprobe() and arch_prepare_optimized_kprobe(), are called inside the text_mutex. So we must hold smp_alt mutex before we go into these arch dependent code. But we can't now, the smp_alt mutex is the arch dependent part, only x86 has it. Maybe we can export another arch dependent callback to solve this.
But there is a simpler way to handle this problem. We can reuse the text_mutex to protect smp_alt_modules instead of using another mutex. And all the arch dependent checks of kprobes are inside the text_mutex, so it's safe now.
Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bp@suse.de Fixes: 2cfa197 "ftrace/alternatives: Introducing *_text_reserved functions" Link: http://lkml.kernel.org/r/1509585501-79466-1-git-send-email-zhouchengming1@huawei.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
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|
#
e8cac8b1 |
| 22-Sep-2017 |
Steven Rostedt (VMware) <rostedt@goodmis.org> |
extable: Enable RCU if it is not watching in kernel_text_address()
If kernel_text_address() is called when RCU is not watching, it can cause an RCU bug because is_module_text_address(), the is_kprob
extable: Enable RCU if it is not watching in kernel_text_address()
If kernel_text_address() is called when RCU is not watching, it can cause an RCU bug because is_module_text_address(), the is_kprobe_*insn_slot() and is_bpf_text_address() functions require the use of RCU.
Only enable RCU if it is not currently watching before it calls is_module_text_address(). The use of rcu_nmi_enter() is used to enable RCU because kernel_text_address() can happen pretty much anywhere (like an NMI), and even from within an NMI. It is called via save_stack_trace() that can be called by any WARN() or tracing function, which can happen while RCU is not watching (for example, going to or coming from idle, or during CPU take down or bring up).
Cc: stable@vger.kernel.org Fixes: 0be964be0 ("module: Sanitize RCU usage and locking") Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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|
#
9aadde91 |
| 22-Sep-2017 |
Steven Rostedt (VMware) <rostedt@goodmis.org> |
extable: Consolidate *kernel_text_address() functions
The functionality between kernel_text_address() and _kernel_text_address() is the same except that _kernel_text_address() does a little more (th
extable: Consolidate *kernel_text_address() functions
The functionality between kernel_text_address() and _kernel_text_address() is the same except that _kernel_text_address() does a little more (that function needs a rename, but that can be done another time). Instead of having duplicate code in both, simply have _kernel_text_address() calls kernel_text_address() instead.
This is marked for stable because there's an RCU bug that can happen if one of these functions gets called while RCU is not watching. That fix depends on this fix to keep from having to write the fix twice.
Cc: stable@vger.kernel.org Fixes: 0be964be0 ("module: Sanitize RCU usage and locking") Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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|
#
a94c33dd |
| 10-Jul-2017 |
Thomas Meyer <thomas@m3y3r.de> |
lib/extable.c: use bsearch() library function in search_extable()
[thomas@m3y3r.de: v3: fix arch specific implementations] Link: http://lkml.kernel.org/r/1497890858.12931.7.camel@m3y3r.de Signed-o
lib/extable.c: use bsearch() library function in search_extable()
[thomas@m3y3r.de: v3: fix arch specific implementations] Link: http://lkml.kernel.org/r/1497890858.12931.7.camel@m3y3r.de Signed-off-by: Thomas Meyer <thomas@m3y3r.de> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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|
#
c0d80dda |
| 06-Jul-2017 |
Marcin Nowakowski <marcin.nowakowski@imgtec.com> |
kernel/extable.c: mark core_kernel_text notrace
core_kernel_text is used by MIPS in its function graph trace processing, so having this method traced leads to an infinite set of recursive calls such
kernel/extable.c: mark core_kernel_text notrace
core_kernel_text is used by MIPS in its function graph trace processing, so having this method traced leads to an infinite set of recursive calls such as:
Call Trace: ftrace_return_to_handler+0x50/0x128 core_kernel_text+0x10/0x1b8 prepare_ftrace_return+0x6c/0x114 ftrace_graph_caller+0x20/0x44 return_to_handler+0x10/0x30 return_to_handler+0x0/0x30 return_to_handler+0x0/0x30 ftrace_ops_no_ops+0x114/0x1bc core_kernel_text+0x10/0x1b8 core_kernel_text+0x10/0x1b8 core_kernel_text+0x10/0x1b8 ftrace_ops_no_ops+0x114/0x1bc core_kernel_text+0x10/0x1b8 prepare_ftrace_return+0x6c/0x114 ftrace_graph_caller+0x20/0x44 (...)
Mark the function notrace to avoid it being traced.
Link: http://lkml.kernel.org/r/1498028607-6765-1-git-send-email-marcin.nowakowski@imgtec.com Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Meyer <thomas@m3y3r.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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0594729c |
| 16-May-2017 |
Thomas Gleixner <tglx@linutronix.de> |
extable: Adjust system_state checks
To enable smp_processor_id() and might_sleep() debug checks earlier, it's required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.
Adjust the sys
extable: Adjust system_state checks
To enable smp_processor_id() and might_sleep() debug checks earlier, it's required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.
Adjust the system_state check in core_kernel_text() to handle the extra states, i.e. to cover init text up to the point where the system switches to state RUNNING.
Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20170516184735.949992741@linutronix.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
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74451e66 |
| 16-Feb-2017 |
Daniel Borkmann <daniel@iogearbox.net> |
bpf: make jited programs visible in traces
Long standing issue with JITed programs is that stack traces from function tracing check whether a given address is kernel code through {__,}kernel_text_ad
bpf: make jited programs visible in traces
Long standing issue with JITed programs is that stack traces from function tracing check whether a given address is kernel code through {__,}kernel_text_address(), which checks for code in core kernel, modules and dynamically allocated ftrace trampolines. But what is still missing is BPF JITed programs (interpreted programs are not an issue as __bpf_prog_run() will be attributed to them), thus when a stack trace is triggered, the code walking the stack won't see any of the JITed ones. The same for address correlation done from user space via reading /proc/kallsyms. This is read by tools like perf, but the latter is also useful for permanent live tracing with eBPF itself in combination with stack maps when other eBPF types are part of the callchain. See offwaketime example on dumping stack from a map.
This work tries to tackle that issue by making the addresses and symbols known to the kernel. The lookup from *kernel_text_address() is implemented through a latched RB tree that can be read under RCU in fast-path that is also shared for symbol/size/offset lookup for a specific given address in kallsyms. The slow-path iteration through all symbols in the seq file done via RCU list, which holds a tiny fraction of all exported ksyms, usually below 0.1 percent. Function symbols are exported as bpf_prog_<tag>, in order to aide debugging and attribution. This facility is currently enabled for root-only when bpf_jit_kallsyms is set to 1, and disabled if hardening is active in any mode. The rationale behind this is that still a lot of systems ship with world read permissions on kallsyms thus addresses should not get suddenly exposed for them. If that situation gets much better in future, we always have the option to change the default on this. Likewise, unprivileged programs are not allowed to add entries there either, but that is less of a concern as most such programs types relevant in this context are for root-only anyway. If enabled, call graphs and stack traces will then show a correct attribution; one example is illustrated below, where the trace is now visible in tooling such as perf script --kallsyms=/proc/kallsyms and friends.
Before:
7fff8166889d bpf_clone_redirect+0x80007f0020ed (/lib/modules/4.9.0-rc8+/build/vmlinux) f5d80 __sendmsg_nocancel+0xffff006451f1a007 (/usr/lib64/libc-2.18.so)
After:
7fff816688b7 bpf_clone_redirect+0x80007f002107 (/lib/modules/4.9.0-rc8+/build/vmlinux) 7fffa0575728 bpf_prog_33c45a467c9e061a+0x8000600020fb (/lib/modules/4.9.0-rc8+/build/vmlinux) 7fffa07ef1fc cls_bpf_classify+0x8000600020dc (/lib/modules/4.9.0-rc8+/build/vmlinux) 7fff81678b68 tc_classify+0x80007f002078 (/lib/modules/4.9.0-rc8+/build/vmlinux) 7fff8164d40b __netif_receive_skb_core+0x80007f0025fb (/lib/modules/4.9.0-rc8+/build/vmlinux) 7fff8164d718 __netif_receive_skb+0x80007f002018 (/lib/modules/4.9.0-rc8+/build/vmlinux) 7fff8164e565 process_backlog+0x80007f002095 (/lib/modules/4.9.0-rc8+/build/vmlinux) 7fff8164dc71 net_rx_action+0x80007f002231 (/lib/modules/4.9.0-rc8+/build/vmlinux) 7fff81767461 __softirqentry_text_start+0x80007f0020d1 (/lib/modules/4.9.0-rc8+/build/vmlinux) 7fff817658ac do_softirq_own_stack+0x80007f00201c (/lib/modules/4.9.0-rc8+/build/vmlinux) 7fff810a2c20 do_softirq+0x80007f002050 (/lib/modules/4.9.0-rc8+/build/vmlinux) 7fff810a2cb5 __local_bh_enable_ip+0x80007f002085 (/lib/modules/4.9.0-rc8+/build/vmlinux) 7fff8168d452 ip_finish_output2+0x80007f002152 (/lib/modules/4.9.0-rc8+/build/vmlinux) 7fff8168ea3d ip_finish_output+0x80007f00217d (/lib/modules/4.9.0-rc8+/build/vmlinux) 7fff8168f2af ip_output+0x80007f00203f (/lib/modules/4.9.0-rc8+/build/vmlinux) [...] 7fff81005854 do_syscall_64+0x80007f002054 (/lib/modules/4.9.0-rc8+/build/vmlinux) 7fff817649eb return_from_SYSCALL_64+0x80007f002000 (/lib/modules/4.9.0-rc8+/build/vmlinux) f5d80 __sendmsg_nocancel+0xffff01c484812007 (/usr/lib64/libc-2.18.so)
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: David S. Miller <davem@davemloft.net>
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8a293be0 |
| 23-Jul-2016 |
Paul Gortmaker <paul.gortmaker@windriver.com> |
core: migrate exception table users off module.h and onto extable.h
These files were including module.h for exception table related functions. We've now separated that content out into its own file
core: migrate exception table users off module.h and onto extable.h
These files were including module.h for exception table related functions. We've now separated that content out into its own file "extable.h" so now move over to that and where possible, avoid all the extra header content in module.h that we don't really need to compile these non-modular files.
Note: init/main.c still needs module.h for __init_or_module kernel/extable.c still needs module.h for is_module_text_address
...and so we don't get the benefit of removing module.h from the cpp feed for these two files, unlike the almost universal 1:1 exchange of module.h for extable.h we were able to do in the arch dirs.
Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Jessica Yu <jeyu@redhat.com> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
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5b485629 |
| 08-Jan-2017 |
Masami Hiramatsu <mhiramat@kernel.org> |
kprobes, extable: Identify kprobes trampolines as kernel text area
Improve __kernel_text_address()/kernel_text_address() to return true if the given address is on a kprobe's instruction slot trampol
kprobes, extable: Identify kprobes trampolines as kernel text area
Improve __kernel_text_address()/kernel_text_address() to return true if the given address is on a kprobe's instruction slot trampoline.
This can help stacktraces to determine the address is on a text area or not.
To implement this atomically in is_kprobe_*_slot(), also change the insn_cache page list to an RCU list.
This changes timings a bit (it delays page freeing to the RCU garbage collection phase), but none of that is in the hot path.
Note: this change can add small overhead to stack unwinders because it adds 2 additional checks to __kernel_text_address(). However, the impact should be very small, because kprobe_insn_pages list has 1 entry per 256 probes(on x86, on arm/arm64 it will be 1024 probes), and kprobe_optinsn_pages has 1 entry per 32 probes(on x86). In most use cases, the number of kprobe events may be less than 20, which means that is_kprobe_*_slot() will check just one entry.
Tested-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/148388747896.6869.6354262871751682264.stgit@devbox [ Improved the changelog and coding style. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
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7c0f6ba6 |
| 24-Dec-2016 |
Linus Torvalds <torvalds@linux-foundation.org> |
Replace <asm/uaccess.h> with <linux/uaccess.h> globally
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PA
Replace <asm/uaccess.h> with <linux/uaccess.h> globally
This was entirely automated, using the script by Al:
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)
to do the replacement at the end of the merge window.
Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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2307e1a3 |
| 09-Sep-2015 |
Wei Yongjun <yongjun_wei@trendmicro.com.cn> |
kernel/extable.c: remove duplicated include
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-
kernel/extable.c: remove duplicated include
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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