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[PATCH] selftests/lkdtm: Add tests for LKDTM targets

by Kees Cook

This adds a basic framework for running all the "safe" lkdtm tests. Signed-off-by: Kees Cook <keescook(a)chromium.org> --- MAINTAINERS | 1 + tools/testing/selftests/Makefile | 1 + tools/testing/selftests/lkdtm/Makefile | 11 ++++ tools/testing/selftests/lkdtm/config | 1 + tools/testing/selftests/lkdtm/run.sh | 86 +++++++++++++++++++++++++ tools/testing/selftests/lkdtm/tests.txt | 64 ++++++++++++++++++ 6 files changed, 164 insertions(+) create mode 100644 tools/testing/selftests/lkdtm/Makefile create mode 100644 tools/testing/selftests/lkdtm/config create mode 100755 tools/testing/selftests/lkdtm/run.sh create mode 100644 tools/testing/selftests/lkdtm/tests.txt diff --git a/MAINTAINERS b/MAINTAINERS index 2c2fce72e694..055f1a09b1da 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -8977,6 +8977,7 @@ LINUX KERNEL DUMP TEST MODULE (LKDTM) M: Kees Cook <keescook(a)chromium.org> S: Maintained F: drivers/misc/lkdtm/* +F: tools/testing/selftests/lkdtm/* LINUX KERNEL MEMORY CONSISTENCY MODEL (LKMM) M: Alan Stern <stern(a)rowland.harvard.edu> diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 971fc8428117..c2397baeb777 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -23,6 +23,7 @@ TARGETS += kcmp TARGETS += kvm TARGETS += lib TARGETS += livepatch +TARGETS += lkdtm TARGETS += membarrier TARGETS += memfd TARGETS += memory-hotplug diff --git a/tools/testing/selftests/lkdtm/Makefile b/tools/testing/selftests/lkdtm/Makefile new file mode 100644 index 000000000000..f322d281fd8e --- /dev/null +++ b/tools/testing/selftests/lkdtm/Makefile @@ -0,0 +1,11 @@ +# SPDX-License-Identifier: GPL-2.0 +# Makefile for LKDTM regression tests + +include ../lib.mk + +# NOTE: $(OUTPUT) won't get default value if used before lib.mk +TEST_GEN_PROGS = $(patsubst %,$(OUTPUT)/%.sh,$(shell awk '{print $$1}' tests.txt | sed -e 's/\#//')) +all: $(TEST_GEN_PROGS) + +$(OUTPUT)/%: run.sh tests.txt + install -m 0744 run.sh $@ diff --git a/tools/testing/selftests/lkdtm/config b/tools/testing/selftests/lkdtm/config new file mode 100644 index 000000000000..d874990e442b --- /dev/null +++ b/tools/testing/selftests/lkdtm/config @@ -0,0 +1 @@ +CONFIG_LKDTM=y diff --git a/tools/testing/selftests/lkdtm/run.sh b/tools/testing/selftests/lkdtm/run.sh new file mode 100755 index 000000000000..117349bf78ca --- /dev/null +++ b/tools/testing/selftests/lkdtm/run.sh @@ -0,0 +1,86 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +# +# This reads tests.txt for the list of LKDTM tests to invoke. Any marked +# with a leading "#" are skipped. The line after the test name is either +# the text to look for in dmesg for a "success", or the rationale for why +# a test is marked to be skipped. +# +set -e +TRIGGER=/sys/kernel/debug/provoke-crash/DIRECT + +# Verify we have LKDTM available in the kernel. +if [ ! -r $TRIGGER ] ; then + /sbin/modprobe -q lkdtm || true + if [ ! -r $TRIGGER ] ; then + echo "Cannot find $TRIGGER (missing CONFIG_LKDTM?)" + else + echo "Cannot write $TRIGGER (need to run as root?)" + fi + # Skip this test + exit 4 +fi + +# Figure out which test to run from our script name. +test=$(basename $0 .sh) +# Look up details about the test from master list of LKDTM tests. +line=$(egrep '^#?'"$test"'\b' tests.txt) +if [ -z "$line" ]; then + echo "Skipped: missing test '$test' in tests.txt" + exit 4 +fi +# Check that the test is known to LKDTM. +if ! egrep -q '^'"$test"'$' "$TRIGGER" ; then + echo "Skipped: test '$test' missing in $TRIGGER!" + exit 4 +fi + +# Extract notes/expected output from test list. +test=$(echo "$line" | cut -d" " -f1) +if echo "$line" | grep -q ' ' ; then + expect=$(echo "$line" | cut -d" " -f2-) +else + expect="" +fi + +# If the test is commented out, report a skip +if echo "$test" | grep -q '^#' ; then + test=$(echo "$test" | cut -c2-) + if [ -z "$expect" ]; then + expect="crashes entire system" + fi + echo "Skipping $test: $expect" + exit 4 +fi + +# If no expected output given, assume an Oops with back trace is success. +if [ -z "$expect" ]; then + expect="call trace:" +fi + +# Clear out dmesg for output reporting +dmesg -c >/dev/null + +# Prepare log for report checking +LOG=$(mktemp --tmpdir -t lkdtm-XXXXXX) +cleanup() { + rm -f "$LOG" +} +trap cleanup EXIT + +# Most shells yell about signals and we're expecting the "cat" process +# to usually be killed by the kernel. So we have to run it in a sub-shell +# and silence errors. +($SHELL -c 'cat <(echo '"$test"') >'"$TRIGGER" 2>/dev/null) || true + +# Record and dump the results +dmesg -c >"$LOG" +cat "$LOG" +# Check for expected output +if grep -qi "$expect" "$LOG" ; then + echo "$test: saw '$expect': ok" + exit 0 +else + echo "$test: missing '$expect': [FAIL]" + exit 1 +fi diff --git a/tools/testing/selftests/lkdtm/tests.txt b/tools/testing/selftests/lkdtm/tests.txt new file mode 100644 index 000000000000..59df8a23db45 --- /dev/null +++ b/tools/testing/selftests/lkdtm/tests.txt @@ -0,0 +1,64 @@ +#PANIC +BUG kernel BUG at +WARNING WARNING: +EXCEPTION BUG: unable to handle kernel +#LOOP Hangs the system +#EXHAUST_STACK Corrupts memory on failure +#CORRUPT_STACK Crashes entire system on success +#CORRUPT_STACK_STRONG Crashes entire system on success +CORRUPT_LIST_ADD list_add corruption +CORRUPT_LIST_DEL list_del corruption +CORRUPT_USER_DS Invalid address limit on user-mode return +STACK_GUARD_PAGE_LEADING +STACK_GUARD_PAGE_TRAILING +UNALIGNED_LOAD_STORE_WRITE +#OVERWRITE_ALLOCATION Corrupts memory on failure +#WRITE_AFTER_FREE Corrupts memory on failure +READ_AFTER_FREE +#WRITE_BUDDY_AFTER_FREE Corrupts memory on failure +READ_BUDDY_AFTER_FREE +#SOFTLOCKUP Hangs the system +#HARDLOCKUP Hangs the system +#SPINLOCKUP Hangs the system +#HUNG_TASK Hangs the system +EXEC_DATA +EXEC_STACK +EXEC_KMALLOC +EXEC_VMALLOC +EXEC_RODATA +EXEC_USERSPACE +EXEC_NULL +ACCESS_USERSPACE +ACCESS_NULL +WRITE_RO +WRITE_RO_AFTER_INIT +WRITE_KERN +REFCOUNT_INC_OVERFLOW +REFCOUNT_ADD_OVERFLOW +REFCOUNT_INC_NOT_ZERO_OVERFLOW +REFCOUNT_ADD_NOT_ZERO_OVERFLOW +REFCOUNT_DEC_ZERO +REFCOUNT_DEC_NEGATIVE Negative detected: saturated +REFCOUNT_DEC_AND_TEST_NEGATIVE Negative detected: saturated +REFCOUNT_SUB_AND_TEST_NEGATIVE Negative detected: saturated +REFCOUNT_INC_ZERO +REFCOUNT_ADD_ZERO +REFCOUNT_INC_SATURATED Saturation detected: still saturated +REFCOUNT_DEC_SATURATED Saturation detected: still saturated +REFCOUNT_ADD_SATURATED Saturation detected: still saturated +REFCOUNT_INC_NOT_ZERO_SATURATED +REFCOUNT_ADD_NOT_ZERO_SATURATED +REFCOUNT_DEC_AND_TEST_SATURATED Saturation detected: still saturated +REFCOUNT_SUB_AND_TEST_SATURATED Saturation detected: still saturated +#REFCOUNT_TIMING timing only +#ATOMIC_TIMING timing only +USERCOPY_HEAP_SIZE_TO +USERCOPY_HEAP_SIZE_FROM +USERCOPY_HEAP_WHITELIST_TO +USERCOPY_HEAP_WHITELIST_FROM +USERCOPY_STACK_FRAME_TO +USERCOPY_STACK_FRAME_FROM +USERCOPY_STACK_BEYOND +USERCOPY_KERNEL +USERCOPY_KERNEL_DS +STACKLEAK_ERASING OK: the rest of the thread stack is properly erased -- 2.17.1 -- Kees Cook

5 years, 8 months

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[PATCH linux-next v10 0/7] ptrace: add PTRACE_GET_SYSCALL_INFO request

by Dmitry V. Levin

[Andrew, could you take this patchset into your tree, please?] PTRACE_GET_SYSCALL_INFO is a generic ptrace API that lets ptracer obtain details of the syscall the tracee is blocked in. There are two reasons for a special syscall-related ptrace request. Firstly, with the current ptrace API there are cases when ptracer cannot retrieve necessary information about syscalls. Some examples include: * The notorious int-0x80-from-64-bit-task issue. See [1] for details. In short, if a 64-bit task performs a syscall through int 0x80, its tracer has no reliable means to find out that the syscall was, in fact, a compat syscall, and misidentifies it. * Syscall-enter-stop and syscall-exit-stop look the same for the tracer. Common practice is to keep track of the sequence of ptrace-stops in order not to mix the two syscall-stops up. But it is not as simple as it looks; for example, strace had a (just recently fixed) long-standing bug where attaching strace to a tracee that is performing the execve system call led to the tracer identifying the following syscall-exit-stop as syscall-enter-stop, which messed up all the state tracking. * Since the introduction of commit 84d77d3f06e7e8dea057d10e8ec77ad71f721be3 ("ptrace: Don't allow accessing an undumpable mm"), both PTRACE_PEEKDATA and process_vm_readv become unavailable when the process dumpable flag is cleared. On such architectures as ia64 this results in all syscall arguments being unavailable for the tracer. Secondly, ptracers also have to support a lot of arch-specific code for obtaining information about the tracee. For some architectures, this requires a ptrace(PTRACE_PEEKUSER, ...) invocation for every syscall argument and return value. PTRACE_GET_SYSCALL_INFO returns the following structure: struct ptrace_syscall_info { __u8 op; /* PTRACE_SYSCALL_INFO_* */ __u32 arch __attribute__((__aligned__(sizeof(__u32)))); __u64 instruction_pointer; __u64 stack_pointer; union { struct { __u64 nr; __u64 args[6]; } entry; struct { __s64 rval; __u8 is_error; } exit; struct { __u64 nr; __u64 args[6]; __u32 ret_data; } seccomp; }; }; The structure was chosen according to [2], except for the following changes: * seccomp substructure was added as a superset of entry substructure; * the type of nr field was changed from int to __u64 because syscall numbers are, as a practical matter, 64 bits; * stack_pointer field was added along with instruction_pointer field since it is readily available and can save the tracer from extra PTRACE_GETREGS/PTRACE_GETREGSET calls; * arch is always initialized to aid with tracing system calls * such as execve(); * instruction_pointer and stack_pointer are always initialized so they could be easily obtained for non-syscall stops; * a boolean is_error field was added along with rval field, this way the tracer can more reliably distinguish a return value from an error value. strace has been ported to PTRACE_GET_SYSCALL_INFO. Starting with release 4.26, strace uses PTRACE_GET_SYSCALL_INFO API as the preferred mechanism of obtaining syscall information. [1] https://lore.kernel.org/lkml/CA+55aFzcSVmdDj9Lh_gdbz1OzHyEm6ZrGPBDAJnywm2LF… [2] https://lore.kernel.org/lkml/CAObL_7GM0n80N7J_DFw_eQyfLyzq+sf4y2AvsCCV88Tb3… --- Notes: v10: added more Acked-by. v9: * Rebased to linux-next again due to syscall_get_arguments() signature change. v8: * Moved syscall_get_arch() specific patches to a separate patchset which is now merged into audit/next tree. * Rebased to linux-next. * Moved ptrace_get_syscall_info code under #ifdef CONFIG_HAVE_ARCH_TRACEHOOK, narrowing down the set of architectures supported by this implementation back to those 19 that enable CONFIG_HAVE_ARCH_TRACEHOOK because I failed to get all syscall_get_*(), instruction_pointer(), and user_stack_pointer() functions implemented on some niche architectures. This leaves the following architectures out: alpha, h8300, m68k, microblaze, and unicore32. v7: * Rebased to v5.0-rc1. * 5 arch-specific preparatory patches out of 25 have been merged into v5.0-rc1 via arch trees. v6: * Add syscall_get_arguments and syscall_set_arguments wrappers to asm-generic/syscall.h, requested by Geert. * Change PTRACE_GET_SYSCALL_INFO return code: do not take trailing paddings into account, use the end of the last field of the structure being written. * Change struct ptrace_syscall_info: * remove .frame_pointer field, is is not needed and not portable; * make .arch field explicitly aligned, remove no longer needed padding before .arch field; * remove trailing pads, they are no longer needed. v5: * Merge separate series and patches into the single series. * Change PTRACE_EVENTMSG_SYSCALL_{ENTRY,EXIT} values as requested by Oleg. * Change struct ptrace_syscall_info: generalize instruction_pointer, stack_pointer, and frame_pointer fields by moving them from ptrace_syscall_info.{entry,seccomp} substructures to ptrace_syscall_info and initializing them for all stops. * Add PTRACE_SYSCALL_INFO_NONE, set it when not in a syscall stop, so e.g. "strace -i" could use PTRACE_SYSCALL_INFO_SECCOMP to obtain instruction_pointer when the tracee is in a signal stop. * Patch all remaining architectures to provide all necessary syscall_get_* functions. * Make available for all architectures: do not conditionalize on CONFIG_HAVE_ARCH_TRACEHOOK since all syscall_get_* functions are implemented on all architectures. * Add a test for PTRACE_GET_SYSCALL_INFO to selftests/ptrace. v4: * Do not introduce task_struct.ptrace_event, use child->last_siginfo->si_code instead. * Implement PTRACE_SYSCALL_INFO_SECCOMP and ptrace_syscall_info.seccomp support along with PTRACE_SYSCALL_INFO_{ENTRY,EXIT} and ptrace_syscall_info.{entry,exit}. v3: * Change struct ptrace_syscall_info. * Support PTRACE_EVENT_SECCOMP by adding ptrace_event to task_struct. * Add proper defines for ptrace_syscall_info.op values. * Rename PT_SYSCALL_IS_ENTERING and PT_SYSCALL_IS_EXITING to PTRACE_EVENTMSG_SYSCALL_ENTRY and PTRACE_EVENTMSG_SYSCALL_EXIT * and move them to uapi. v2: * Do not use task->ptrace. * Replace entry_info.is_compat with entry_info.arch, use syscall_get_arch(). * Use addr argument of sys_ptrace to get expected size of the struct; return full size of the struct. Dmitry V. Levin (6): nds32: fix asm/syscall.h # acked hexagon: define syscall_get_error() and syscall_get_return_value() # waiting for ack since November mips: define syscall_get_error() # acked parisc: define syscall_get_error() # acked powerpc: define syscall_get_error() # waiting for ack since early December selftests/ptrace: add a test case for PTRACE_GET_SYSCALL_INFO # acked Elvira Khabirova (1): ptrace: add PTRACE_GET_SYSCALL_INFO request # reviewed arch/hexagon/include/asm/syscall.h | 14 + arch/mips/include/asm/syscall.h | 6 + arch/nds32/include/asm/syscall.h | 27 +- arch/parisc/include/asm/syscall.h | 7 + arch/powerpc/include/asm/syscall.h | 10 + include/linux/tracehook.h | 9 +- include/uapi/linux/ptrace.h | 35 +++ kernel/ptrace.c | 103 ++++++- tools/testing/selftests/ptrace/.gitignore | 1 + tools/testing/selftests/ptrace/Makefile | 2 +- .../selftests/ptrace/get_syscall_info.c | 271 ++++++++++++++++++ 11 files changed, 470 insertions(+), 15 deletions(-) create mode 100644 tools/testing/selftests/ptrace/get_syscall_info.c -- ldv

5 years, 8 months

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next-20190509 kselftest results

by ci_notify＠linaro.org

Summary ------------------------------------------------------------------------ kernel: 5.1.0 git repo: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git branch: master git commit: unknown git describe: next-20190509 Test details: https://qa-reports.linaro.org/lkft/linux-next-oe/build/next-20190509 Regressions (compared to build next-20190507) ------------------------------------------------------------------------ No regressions Fixes (compared to build next-20190507) ------------------------------------------------------------------------ No fixes In total: ------------------------------------------------------------------------ Ran 0 total tests in the following environments and test suites. pass 0 fail 0 xfail 0 skip 0 Environments -------------- - x15 - arm Test Suites ----------- Failures ------------------------------------------------------------------------ x15: Skips ------------------------------------------------------------------------ No skips -- Linaro LKFT https://lkft.linaro.org

5 years, 8 months

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[PATCH 0/4] x86: int3 fallout

by Peter Zijlstra

So the first 3 patches are cleanups and fixes and should probably just go in. The last patch however is the one Linus hates, it converts i386 to always have a complete pt_regs. Both Josh and me did a bunch of cleanups and the patch is now a net reduction in lines. I still think it is the right thing to do; it removes a whole lot of magic from the C code (and avoids future surprises), but if this cannot convince Linus, I'll not pursue this further.

5 years, 8 months

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[for-next][PATCH 03/13] ftrace/x86_64: Emulate call function while updating in breakpoint handler

by Steven Rostedt

From: Peter Zijlstra <peterz(a)infradead.org> Nicolai Stange discovered[1] that if live kernel patching is enabled, and the function tracer started tracing the same function that was patched, the conversion of the fentry call site during the translation of going from calling the live kernel patch trampoline to the iterator trampoline, would have as slight window where it didn't call anything. As live kernel patching depends on ftrace to always call its code (to prevent the function being traced from being called, as it will redirect it). This small window would allow the old buggy function to be called, and this can cause undesirable results. Nicolai submitted new patches[2] but these were controversial. As this is similar to the static call emulation issues that came up a while ago[3]. But after some debate[4][5] adding a gap in the stack when entering the breakpoint handler allows for pushing the return address onto the stack to easily emulate a call. [1] http://lkml.kernel.org/r/20180726104029.7736-1-nstange@suse.de [2] http://lkml.kernel.org/r/20190427100639.15074-1-nstange@suse.de [3] http://lkml.kernel.org/r/3cf04e113d71c9f8e4be95fb84a510f085aa4afa.154171145… [4] http://lkml.kernel.org/r/CAHk-=wh5OpheSU8Em_Q3Hg8qw_JtoijxOdPtHru6d+5K8TWM=… [5] http://lkml.kernel.org/r/CAHk-=wjvQxY4DvPrJ6haPgAa6b906h=MwZXO6G8OtiTGe=N7_… [ Live kernel patching is not implemented on x86_32, thus the emulate calls are only for x86_64. ] Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Nicolai Stange <nstange(a)suse.de> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Borislav Petkov <bp(a)alien8.de> Cc: "H. Peter Anvin" <hpa(a)zytor.com> Cc: the arch/x86 maintainers <x86(a)kernel.org> Cc: Josh Poimboeuf <jpoimboe(a)redhat.com> Cc: Jiri Kosina <jikos(a)kernel.org> Cc: Miroslav Benes <mbenes(a)suse.cz> Cc: Petr Mladek <pmladek(a)suse.com> Cc: Joe Lawrence <joe.lawrence(a)redhat.com> Cc: Shuah Khan <shuah(a)kernel.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com> Cc: Tim Chen <tim.c.chen(a)linux.intel.com> Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de> Cc: Mimi Zohar <zohar(a)linux.ibm.com> Cc: Juergen Gross <jgross(a)suse.com> Cc: Nick Desaulniers <ndesaulniers(a)google.com> Cc: Nayna Jain <nayna(a)linux.ibm.com> Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com> Cc: Joerg Roedel <jroedel(a)suse.de> Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org> Cc: stable(a)vger.kernel.org Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching") Tested-by: Nicolai Stange <nstange(a)suse.de> Reviewed-by: Nicolai Stange <nstange(a)suse.de> Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> [ Changed to only implement emulated calls for x86_64 ] Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org> --- arch/x86/kernel/ftrace.c | 32 +++++++++++++++++++++++++++----- 1 file changed, 27 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c index ef49517f6bb2..bd553b3af22e 100644 --- a/arch/x86/kernel/ftrace.c +++ b/arch/x86/kernel/ftrace.c @@ -29,6 +29,7 @@ #include <asm/kprobes.h> #include <asm/ftrace.h> #include <asm/nops.h> +#include <asm/text-patching.h> #ifdef CONFIG_DYNAMIC_FTRACE @@ -231,6 +232,7 @@ int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr, } static unsigned long ftrace_update_func; +static unsigned long ftrace_update_func_call; static int update_ftrace_func(unsigned long ip, void *new) { @@ -259,6 +261,8 @@ int ftrace_update_ftrace_func(ftrace_func_t func) unsigned char *new; int ret; + ftrace_update_func_call = (unsigned long)func; + new = ftrace_call_replace(ip, (unsigned long)func); ret = update_ftrace_func(ip, new); @@ -294,13 +298,28 @@ int ftrace_int3_handler(struct pt_regs *regs) if (WARN_ON_ONCE(!regs)) return 0; - ip = regs->ip - 1; - if (!ftrace_location(ip) && !is_ftrace_caller(ip)) - return 0; + ip = regs->ip - INT3_INSN_SIZE; - regs->ip += MCOUNT_INSN_SIZE - 1; +#ifdef CONFIG_X86_64 + if (ftrace_location(ip)) { + int3_emulate_call(regs, (unsigned long)ftrace_regs_caller); + return 1; + } else if (is_ftrace_caller(ip)) { + if (!ftrace_update_func_call) { + int3_emulate_jmp(regs, ip + CALL_INSN_SIZE); + return 1; + } + int3_emulate_call(regs, ftrace_update_func_call); + return 1; + } +#else + if (ftrace_location(ip) || is_ftrace_caller(ip)) { + int3_emulate_jmp(regs, ip + CALL_INSN_SIZE); + return 1; + } +#endif - return 1; + return 0; } NOKPROBE_SYMBOL(ftrace_int3_handler); @@ -859,6 +878,8 @@ void arch_ftrace_update_trampoline(struct ftrace_ops *ops) func = ftrace_ops_get_func(ops); + ftrace_update_func_call = (unsigned long)func; + /* Do a safe modify in case the trampoline is executing */ new = ftrace_call_replace(ip, (unsigned long)func); ret = update_ftrace_func(ip, new); @@ -960,6 +981,7 @@ static int ftrace_mod_jmp(unsigned long ip, void *func) { unsigned char *new; + ftrace_update_func_call = 0UL; new = ftrace_jmp_replace(ip, (unsigned long)func); return update_ftrace_func(ip, new); -- 2.20.1

5 years, 8 months

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[for-next][PATCH 02/13] x86_64: Allow breakpoints to emulate call instructions

by Steven Rostedt

From: Peter Zijlstra <peterz(a)infradead.org> In order to allow breakpoints to emulate call instructions, they need to push the return address onto the stack. The x86_64 int3 handler adds a small gap to allow the stack to grow some. Use this gap to add the return address to be able to emulate a call instruction at the breakpoint location. These helper functions are added: int3_emulate_jmp(): changes the location of the regs->ip to return there. (The next two are only for x86_64) int3_emulate_push(): to push the address onto the gap in the stack int3_emulate_call(): push the return address and change regs->ip Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Nicolai Stange <nstange(a)suse.de> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Borislav Petkov <bp(a)alien8.de> Cc: "H. Peter Anvin" <hpa(a)zytor.com> Cc: the arch/x86 maintainers <x86(a)kernel.org> Cc: Josh Poimboeuf <jpoimboe(a)redhat.com> Cc: Jiri Kosina <jikos(a)kernel.org> Cc: Miroslav Benes <mbenes(a)suse.cz> Cc: Petr Mladek <pmladek(a)suse.com> Cc: Joe Lawrence <joe.lawrence(a)redhat.com> Cc: Shuah Khan <shuah(a)kernel.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com> Cc: Tim Chen <tim.c.chen(a)linux.intel.com> Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de> Cc: Mimi Zohar <zohar(a)linux.ibm.com> Cc: Juergen Gross <jgross(a)suse.com> Cc: Nick Desaulniers <ndesaulniers(a)google.com> Cc: Nayna Jain <nayna(a)linux.ibm.com> Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com> Cc: Joerg Roedel <jroedel(a)suse.de> Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org> Cc: stable(a)vger.kernel.org Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching") Tested-by: Nicolai Stange <nstange(a)suse.de> Reviewed-by: Nicolai Stange <nstange(a)suse.de> Reviewed-by: Masami Hiramatsu <mhiramat(a)kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> [ Modified to only work for x86_64 and added comment to int3_emulate_push() ] Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org> --- arch/x86/include/asm/text-patching.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h index e85ff65c43c3..05861cc08787 100644 --- a/arch/x86/include/asm/text-patching.h +++ b/arch/x86/include/asm/text-patching.h @@ -39,4 +39,32 @@ extern int poke_int3_handler(struct pt_regs *regs); extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler); extern int after_bootmem; +static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip) +{ + regs->ip = ip; +} + +#define INT3_INSN_SIZE 1 +#define CALL_INSN_SIZE 5 + +#ifdef CONFIG_X86_64 +static inline void int3_emulate_push(struct pt_regs *regs, unsigned long val) +{ + /* + * The int3 handler in entry_64.S adds a gap between the + * stack where the break point happened, and the saving of + * pt_regs. We can extend the original stack because of + * this gap. See the idtentry macro's create_gap option. + */ + regs->sp -= sizeof(unsigned long); + *(unsigned long *)regs->sp = val; +} + +static inline void int3_emulate_call(struct pt_regs *regs, unsigned long func) +{ + int3_emulate_push(regs, regs->ip - INT3_INSN_SIZE + CALL_INSN_SIZE); + int3_emulate_jmp(regs, func); +} +#endif + #endif /* _ASM_X86_TEXT_PATCHING_H */ -- 2.20.1

5 years, 8 months

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[RFC][PATCH 1/2] x86: Allow breakpoints to emulate call functions

by Steven Rostedt

From: Peter Zijlstra <peterz(a)infradead.org> In order to allow breakpoints to emulate call functions, they need to push the return address onto the stack. But because the breakpoint exception frame is added to the stack when the breakpoint is hit, there's no room to add the address onto the stack and return to the address of the emulated called funtion. To handle this, copy the exception frame on entry of the breakpoint handler and have leave a gap that can be used to add a return address to the stack frame and return from the breakpoint to the emulated called function, allowing for that called function to return back to the location after the breakpoint was placed. The helper functions were also added: int3_emulate_push(): to push the address onto the gap in the stack int3_emulate_jmp(): changes the location of the regs->ip to return there. int3_emulate_call(): push the return address and change regs->ip Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Nicolai Stange <nstange(a)suse.de> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Borislav Petkov <bp(a)alien8.de> Cc: "H. Peter Anvin" <hpa(a)zytor.com> Cc: the arch/x86 maintainers <x86(a)kernel.org> Cc: Josh Poimboeuf <jpoimboe(a)redhat.com> Cc: Jiri Kosina <jikos(a)kernel.org> Cc: Miroslav Benes <mbenes(a)suse.cz> Cc: Petr Mladek <pmladek(a)suse.com> Cc: Joe Lawrence <joe.lawrence(a)redhat.com> Cc: Shuah Khan <shuah(a)kernel.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk(a)oracle.com> Cc: Tim Chen <tim.c.chen(a)linux.intel.com> Cc: Sebastian Andrzej Siewior <bigeasy(a)linutronix.de> Cc: Mimi Zohar <zohar(a)linux.ibm.com> Cc: Juergen Gross <jgross(a)suse.com> Cc: Nick Desaulniers <ndesaulniers(a)google.com> Cc: Nayna Jain <nayna(a)linux.ibm.com> Cc: Masahiro Yamada <yamada.masahiro(a)socionext.com> Cc: Joerg Roedel <jroedel(a)suse.de> Cc: "open list:KERNEL SELFTEST FRAMEWORK" <linux-kselftest(a)vger.kernel.org> Cc: stable(a)vger.kernel.org Fixes: b700e7f03df5 ("livepatch: kernel: add support for live patching") Signed-off-by: *** Need Peter Zijlstra's SoB here! *** Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org> --- arch/x86/entry/entry_32.S | 11 +++++++++++ arch/x86/entry/entry_64.S | 14 ++++++++++++-- arch/x86/include/asm/text-patching.h | 20 ++++++++++++++++++++ 3 files changed, 43 insertions(+), 2 deletions(-) diff --git a/arch/x86/entry/entry_32.S b/arch/x86/entry/entry_32.S index d309f30cf7af..50bbf4035baf 100644 --- a/arch/x86/entry/entry_32.S +++ b/arch/x86/entry/entry_32.S @@ -1478,6 +1478,17 @@ ENTRY(int3) ASM_CLAC pushl $-1 # mark this as an int +#ifdef CONFIG_VM86 + testl $X86_EFLAGS_VM, PT_EFLAGS(%esp) + jnz .Lfrom_usermode_no_gap +#endif + testl $SEGMENT_RPL_MASK, PT_CS(%esp) + jnz .Lfrom_usermode_no_gap + .rept 6 + pushl 5*4(%esp) + .endr +.Lfrom_usermode_no_gap: + SAVE_ALL switch_stacks=1 ENCODE_FRAME_POINTER TRACE_IRQS_OFF diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 1f0efdb7b629..834ec1397dab 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -879,7 +879,7 @@ apicinterrupt IRQ_WORK_VECTOR irq_work_interrupt smp_irq_work_interrupt * @paranoid == 2 is special: the stub will never switch stacks. This is for * #DF: if the thread stack is somehow unusable, we'll still get a useful OOPS. */ -.macro idtentry sym do_sym has_error_code:req paranoid=0 shift_ist=-1 +.macro idtentry sym do_sym has_error_code:req paranoid=0 shift_ist=-1 create_gap=0 ENTRY(\sym) UNWIND_HINT_IRET_REGS offset=\has_error_code*8 @@ -899,6 +899,16 @@ ENTRY(\sym) jnz .Lfrom_usermode_switch_stack_\@ .endif + .if \create_gap == 1 + testb $3, CS-ORIG_RAX(%rsp) + jnz .Lfrom_usermode_no_gap_\@ + .rept 6 + pushq 5*8(%rsp) + .endr + UNWIND_HINT_IRET_REGS offset=8 +.Lfrom_usermode_no_gap_\@: + .endif + .if \paranoid call paranoid_entry .else @@ -1130,7 +1140,7 @@ apicinterrupt3 HYPERV_STIMER0_VECTOR \ #endif /* CONFIG_HYPERV */ idtentry debug do_debug has_error_code=0 paranoid=1 shift_ist=DEBUG_STACK -idtentry int3 do_int3 has_error_code=0 +idtentry int3 do_int3 has_error_code=0 create_gap=1 idtentry stack_segment do_stack_segment has_error_code=1 #ifdef CONFIG_XEN_PV diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/text-patching.h index e85ff65c43c3..ba275b6292db 100644 --- a/arch/x86/include/asm/text-patching.h +++ b/arch/x86/include/asm/text-patching.h @@ -39,4 +39,24 @@ extern int poke_int3_handler(struct pt_regs *regs); extern void *text_poke_bp(void *addr, const void *opcode, size_t len, void *handler); extern int after_bootmem; +static inline void int3_emulate_push(struct pt_regs *regs, unsigned long val) +{ + regs->sp -= sizeof(unsigned long); + *(unsigned long *)regs->sp = val; +} + +static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned long ip) +{ + regs->ip = ip; +} + +#define INT3_INSN_SIZE 1 +#define CALL_INSN_SIZE 5 + +static inline void int3_emulate_call(struct pt_regs *regs, unsigned long func) +{ + int3_emulate_push(regs, regs->ip - INT3_INSN_SIZE + CALL_INSN_SIZE); + int3_emulate_jmp(regs, func); +} + #endif /* _ASM_X86_TEXT_PATCHING_H */ -- 2.20.1

5 years, 8 months

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[PATCH] selftests: fix install target to use default install path

by Shuah Khan

Install target fails when INSTALL_PATH is undefined. Fix install target to use "output_dir/install as the default install location. "output_dir" is either the root of selftests directory under kernel source tree or output directory specified by O= or KBUILD_OUTPUT. e.g: make -C tools/testing/selftests install <installs under tools/testing/selftests/install> make O=/tmp/kselftest -C tools/testing/selftests install <installs under /tmp/kselftest/install> export KBUILD_OUTPUT=/tmp/kselftest make -C tools/testing/selftests install <installs under /tmp/kselftest/install> In addition, add "all" target as dependency to "install" to build and install using a single command. Signed-off-by: Shuah Khan <skhan(a)linuxfoundation.org> --- tools/testing/selftests/Makefile | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile index 9f05448e5e4b..c71a63b923d4 100644 --- a/tools/testing/selftests/Makefile +++ b/tools/testing/selftests/Makefile @@ -163,11 +163,17 @@ clean_hotplug: run_pstore_crash: make -C pstore run_crash -INSTALL_PATH ?= install +# Use $BUILD as the default install root. $BUILD points to the +# right output location for the following cases: +# 1. output_dir=kernel_src +# 2. a separate output directory is specified using O= KBUILD_OUTPUT +# 3. a separate output directory is specified using KBUILD_OUTPUT +# +INSTALL_PATH ?= $(BUILD)/install INSTALL_PATH := $(abspath $(INSTALL_PATH)) ALL_SCRIPT := $(INSTALL_PATH)/run_kselftest.sh -install: +install: all ifdef INSTALL_PATH @# Ask all targets to install their files mkdir -p $(INSTALL_PATH)/kselftest -- 2.17.1

5 years, 8 months

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[PATCH net-next] net: sched: Introduce act_ctinfo action

by Kevin 'ldir' Darbyshire-Bryant

ctinfo is a new tc filter action module. It is designed to restore DSCPs stored in conntrack marks into the ipv4/v6 diffserv field. The feature is intended for use and has been found useful for restoring ingress classifications based on egress classifications across links that bleach or otherwise change DSCP, typically home ISP Internet links. Restoring DSCP on ingress on the WAN link allows qdiscs such as CAKE to shape inbound packets according to policies that are easier to indicate on egress. Ingress classification is traditionally a challenging task since iptables rules haven't yet run and tc filter/eBPF programs are pre-NAT lookups, hence are unable to see internal IPv4 addresses as used on the typical home masquerading gateway. ctinfo understands the following parameters: dscp dscpmask[/statemask] dscpmask - a 32 bit mask of at least 6 contiguous bits and indicates where ctinfo will find the DSCP bits stored in the conntrack mark. statemask - a 32 bit mask of (usually) 1 bit length, outside the area specified by dscpmask. This represents a conditional operation flag whereby the DSCP is only restored if the flag is set. This is useful to implement a 'one shot' iptables based classification where the 'complicated' iptables rules are only run once to classify the connection on initial (egress) packet and subsequent packets are all marked/restored with the same DSCP. A mask of zero disables the conditional behaviour ie. the conntrack mark DSCP bits are always restored to the ip diffserv field (assuming the conntrack entry is found & the skb is an ipv4/ipv6 type) optional parameters: zone - conntrack zone control - action related control (reclassify | pipe | drop | continue | ok | goto chain <CHAIN_INDEX>) e.g. dscp 0xfc000000/0x01000000 |----0xFC----conntrack mark----000000---| | Bits 31-26 | bit 25 | bit24 |~~~ Bit 0| | DSCP | unused | flag |unused | |-----------------------0x01---000000---| | | | | ---| Conditional flag v only restore if set |-ip diffserv-| | 6 bits | |-------------| Signed-off-by: Kevin Darbyshire-Bryant <ldir(a)darbyshire-bryant.me.uk> --- include/net/tc_act/tc_ctinfo.h | 24 ++ include/uapi/linux/pkt_cls.h | 1 + include/uapi/linux/tc_act/tc_ctinfo.h | 33 ++ net/sched/Kconfig | 13 + net/sched/Makefile | 1 + net/sched/act_ctinfo.c | 375 ++++++++++++++++++++++ tools/testing/selftests/tc-testing/config | 1 + 7 files changed, 448 insertions(+) create mode 100644 include/net/tc_act/tc_ctinfo.h create mode 100644 include/uapi/linux/tc_act/tc_ctinfo.h create mode 100644 net/sched/act_ctinfo.c diff --git a/include/net/tc_act/tc_ctinfo.h b/include/net/tc_act/tc_ctinfo.h new file mode 100644 index 000000000000..bb33e66d3ea5 --- /dev/null +++ b/include/net/tc_act/tc_ctinfo.h @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __NET_TC_CTINFO_H +#define __NET_TC_CTINFO_H + +#include <net/act_api.h> + +struct tcf_ctinfo_params { + struct net *net; + u32 dscpmask; + u32 dscpstatemask; + u16 zone; + u8 mode; + u8 dscpmaskshift; + struct rcu_head rcu; +}; + +struct tcf_ctinfo { + struct tc_action common; + struct tcf_ctinfo_params __rcu *params; +}; + +#define to_ctinfo(a) ((struct tcf_ctinfo *)a) + +#endif /* __NET_TC_CTINFO_H */ diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h index 51a0496f78ea..a93680fc4bfa 100644 --- a/include/uapi/linux/pkt_cls.h +++ b/include/uapi/linux/pkt_cls.h @@ -105,6 +105,7 @@ enum tca_id { TCA_ID_IFE = TCA_ACT_IFE, TCA_ID_SAMPLE = TCA_ACT_SAMPLE, /* other actions go here */ + TCA_ID_CTINFO, __TCA_ID_MAX = 255 }; diff --git a/include/uapi/linux/tc_act/tc_ctinfo.h b/include/uapi/linux/tc_act/tc_ctinfo.h new file mode 100644 index 000000000000..b84902b5e3b1 --- /dev/null +++ b/include/uapi/linux/tc_act/tc_ctinfo.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef __UAPI_TC_CTINFO_H +#define __UAPI_TC_CTINFO_H + +#include <linux/types.h> +#include <linux/pkt_cls.h> + +struct tc_ctinfo { + tc_gen; +}; + +struct tc_ctinfo_dscp { + __u32 mask; + __u32 statemask; +}; + +enum { + TCA_CTINFO_UNSPEC, + TCA_CTINFO_ACT, + TCA_CTINFO_ZONE, + TCA_CTINFO_DSCP_PARMS, + TCA_CTINFO_MODE_DSCP, + TCA_CTINFO_TM, + TCA_CTINFO_PAD, + __TCA_CTINFO_MAX +}; +#define TCA_CTINFO_MAX (__TCA_CTINFO_MAX - 1) + +enum { + CTINFO_MODE_SETDSCP = BIT(0) +}; + +#endif diff --git a/net/sched/Kconfig b/net/sched/Kconfig index 5c02ad97ef23..5ac01c5ebae9 100644 --- a/net/sched/Kconfig +++ b/net/sched/Kconfig @@ -876,6 +876,19 @@ config NET_ACT_CONNMARK To compile this code as a module, choose M here: the module will be called act_connmark. +config NET_ACT_CTINFO + tristate "Netfilter Connmark to DSCP Retriever" + depends on NET_CLS_ACT && NETFILTER && IP_NF_IPTABLES + depends on NF_CONNTRACK && NF_CONNTRACK_MARK + help + Say Y here to allow transfer of a connmark stored DSCP into + ipv4/v6 diffserv + + If unsure, say N. + + To compile this code as a module, choose M here: the + module will be called act_ctinfo. + config NET_ACT_SKBMOD tristate "skb data modification action" depends on NET_CLS_ACT diff --git a/net/sched/Makefile b/net/sched/Makefile index 8a40431d7b5c..d54bfcbd7981 100644 --- a/net/sched/Makefile +++ b/net/sched/Makefile @@ -21,6 +21,7 @@ obj-$(CONFIG_NET_ACT_CSUM) += act_csum.o obj-$(CONFIG_NET_ACT_VLAN) += act_vlan.o obj-$(CONFIG_NET_ACT_BPF) += act_bpf.o obj-$(CONFIG_NET_ACT_CONNMARK) += act_connmark.o +obj-$(CONFIG_NET_ACT_CTINFO) += act_ctinfo.o obj-$(CONFIG_NET_ACT_SKBMOD) += act_skbmod.o obj-$(CONFIG_NET_ACT_IFE) += act_ife.o obj-$(CONFIG_NET_IFE_SKBMARK) += act_meta_mark.o diff --git a/net/sched/act_ctinfo.c b/net/sched/act_ctinfo.c new file mode 100644 index 000000000000..01a8694651ea --- /dev/null +++ b/net/sched/act_ctinfo.c @@ -0,0 +1,375 @@ +// SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note +/* net/sched/act_ctinfo.c netfilter ctinfo connmark->DSCP action + * + * Copyright (c) 2019 Kevin Darbyshire-Bryant <ldir(a)darbyshire-bryant.me.uk> + * + * 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. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/skbuff.h> +#include <linux/rtnetlink.h> +#include <linux/pkt_cls.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <net/netlink.h> +#include <net/pkt_sched.h> +#include <net/act_api.h> +#include <net/pkt_cls.h> +#include <uapi/linux/tc_act/tc_ctinfo.h> +#include <net/tc_act/tc_ctinfo.h> + +#include <net/netfilter/nf_conntrack.h> +#include <net/netfilter/nf_conntrack_core.h> +#include <net/netfilter/nf_conntrack_ecache.h> +#include <net/netfilter/nf_conntrack_zones.h> + +static unsigned int ctinfo_net_id; +static struct tc_action_ops act_ctinfo_ops; + +static void tcf_ctinfo_dscp_set(struct nf_conn *ct, struct tcf_ctinfo *ca, + struct tcf_ctinfo_params *cp, + struct sk_buff *skb, int wlen, int proto) +{ + u8 dscp, newdscp; + + newdscp = (((ct->mark & cp->dscpmask) >> cp->dscpmaskshift) << 2) & + ~INET_ECN_MASK; + + /* mark contains DSCP so restore DSCP bits from c->mark into diffserv */ + /* using overlimits stats to count how many DSCP updates */ + switch (proto) { + case NFPROTO_IPV4: + dscp = ipv4_get_dsfield(ip_hdr(skb)) & ~INET_ECN_MASK; + if (dscp != newdscp) { + if (!skb_try_make_writable(skb, wlen)) { + ipv4_change_dsfield(ip_hdr(skb), + INET_ECN_MASK, + newdscp); + ca->tcf_qstats.overlimits++; + } else { + ca->tcf_qstats.drops++; + } + } + break; + case NFPROTO_IPV6: + dscp = ipv6_get_dsfield(ipv6_hdr(skb)) & ~INET_ECN_MASK; + if (dscp != newdscp) { + if (!skb_try_make_writable(skb, wlen)) { + ipv6_change_dsfield(ipv6_hdr(skb), + INET_ECN_MASK, + newdscp); + ca->tcf_qstats.overlimits++; + } else { + ca->tcf_qstats.drops++; + } + } + break; + default: + break; + } +} + +static int tcf_ctinfo_act(struct sk_buff *skb, const struct tc_action *a, + struct tcf_result *res) +{ + const struct nf_conntrack_tuple_hash *thash = NULL; + struct nf_conntrack_tuple tuple; + enum ip_conntrack_info ctinfo; + struct tcf_ctinfo *ca = to_ctinfo(a); + struct tcf_ctinfo_params *cp; + struct nf_conntrack_zone zone; + struct nf_conn *ct; + int proto, wlen; + int action; + + cp = rcu_dereference_bh(ca->params); + + tcf_lastuse_update(&ca->tcf_tm); + bstats_update(&ca->tcf_bstats, skb); + action = READ_ONCE(ca->tcf_action); + + /* currently the only mode we know but in future...*/ + if (unlikely(!(cp->mode & CTINFO_MODE_SETDSCP))) + goto out; + + wlen = skb_network_offset(skb); + if (tc_skb_protocol(skb) == htons(ETH_P_IP)) { + wlen += sizeof(struct iphdr); + if (!pskb_may_pull(skb, wlen)) + goto out; + + proto = NFPROTO_IPV4; + } else if (tc_skb_protocol(skb) == htons(ETH_P_IPV6)) { + wlen += sizeof(struct ipv6hdr); + if (!pskb_may_pull(skb, wlen)) + goto out; + + proto = NFPROTO_IPV6; + } else { + goto out; + } + + ct = nf_ct_get(skb, &ctinfo); + if (!ct) { /* look harder usually ingress */ + if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), + proto, cp->net, &tuple)) + goto out; + zone.id = cp->zone; + zone.dir = NF_CT_DEFAULT_ZONE_DIR; + + thash = nf_conntrack_find_get(cp->net, &zone, &tuple); + if (!thash) + goto out; + + ct = nf_ct_tuplehash_to_ctrack(thash); + } + + if (!cp->dscpstatemask || (ct->mark & cp->dscpstatemask)) + tcf_ctinfo_dscp_set(ct, ca, cp, skb, wlen, proto); + + if (thash) + nf_ct_put(ct); +out: + return action; +} + +static const struct nla_policy ctinfo_policy[TCA_CTINFO_MAX + 1] = { + [TCA_CTINFO_ACT] = { .len = sizeof(struct tc_ctinfo) }, + [TCA_CTINFO_ZONE] = { .type = NLA_U16 }, + [TCA_CTINFO_MODE_DSCP] = { .type = NLA_FLAG }, + [TCA_CTINFO_DSCP_PARMS] = { .len = sizeof(struct tc_ctinfo_dscp) }, +}; + +static int tcf_ctinfo_init(struct net *net, struct nlattr *nla, + struct nlattr *est, struct tc_action **a, + int ovr, int bind, bool rtnl_held, + struct tcf_proto *tp, + struct netlink_ext_ack *extack) +{ + struct tc_action_net *tn = net_generic(net, ctinfo_net_id); + struct tcf_ctinfo_params *cp_new; + struct nlattr *tb[TCA_CTINFO_MAX + 1]; + struct tcf_chain *goto_ch = NULL; + struct tcf_ctinfo *ci; + struct tc_ctinfo *actparm; + struct tc_ctinfo_dscp *dscpparm; + int ret = 0, err, i; + + if (!nla) + return -EINVAL; + + err = nla_parse_nested(tb, TCA_CTINFO_MAX, nla, ctinfo_policy, NULL); + if (err < 0) + return err; + + if (!tb[TCA_CTINFO_ACT]) + return -EINVAL; + + if (tb[TCA_CTINFO_MODE_DSCP] && !tb[TCA_CTINFO_DSCP_PARMS]) + return -EINVAL; + + actparm = nla_data(tb[TCA_CTINFO_ACT]); + dscpparm = nla_data(tb[TCA_CTINFO_DSCP_PARMS]); + + if (dscpparm) { + /* need at least contiguous 6 bit mask */ + i = dscpparm->mask ? __ffs(dscpparm->mask) : 0; + if ((0x3f & (dscpparm->mask >> i)) != 0x3f) + return -EINVAL; + /* mask & statemask must not overlap */ + if (dscpparm->mask & dscpparm->statemask) + return -EINVAL; + } +//done the validation:now to the actual action allocation + err = tcf_idr_check_alloc(tn, &actparm->index, a, bind); + if (!err) { + ret = tcf_idr_create(tn, actparm->index, est, a, + &act_ctinfo_ops, bind, false); + if (ret) { + tcf_idr_cleanup(tn, actparm->index); + return ret; + } + } else if (err > 0) { + if (bind) /* don't override defaults */ + return 0; + if (!ovr) { + tcf_idr_release(*a, bind); + return -EEXIST; + } + } else { + return err; + } + + err = tcf_action_check_ctrlact(actparm->action, tp, &goto_ch, extack); + if (err < 0) + goto release_idr; + + ci = to_ctinfo(*a); + + cp_new = kzalloc(sizeof(*cp_new), GFP_KERNEL); + if (unlikely(!cp_new)) { + err = -ENOMEM; + goto put_chain; + } + + cp_new->net = net; + cp_new->zone = tb[TCA_CTINFO_ZONE] ? + nla_get_u16(tb[TCA_CTINFO_ZONE]) : 0; + if (dscpparm) { + cp_new->dscpmask = dscpparm->mask; + cp_new->dscpmaskshift = cp_new->dscpmask ? + __ffs(cp_new->dscpmask) : 0; + cp_new->dscpstatemask = dscpparm->statemask; + } + + if (tb[TCA_CTINFO_MODE_DSCP]) + cp_new->mode |= CTINFO_MODE_SETDSCP; + else + cp_new->mode &= ~CTINFO_MODE_SETDSCP; + + spin_lock_bh(&ci->tcf_lock); + goto_ch = tcf_action_set_ctrlact(*a, actparm->action, goto_ch); + rcu_swap_protected(ci->params, cp_new, + lockdep_is_held(&ci->tcf_lock)); + spin_unlock_bh(&ci->tcf_lock); + + if (goto_ch) + tcf_chain_put_by_act(goto_ch); + if (cp_new) + kfree_rcu(cp_new, rcu); + + if (ret == ACT_P_CREATED) + tcf_idr_insert(tn, *a); + + return ret; + +put_chain: + if (goto_ch) + tcf_chain_put_by_act(goto_ch); +release_idr: + tcf_idr_release(*a, bind); + return err; +} + +static inline int tcf_ctinfo_dump(struct sk_buff *skb, struct tc_action *a, + int bind, int ref) +{ + unsigned char *b = skb_tail_pointer(skb); + struct tcf_ctinfo *ci = to_ctinfo(a); + struct tcf_ctinfo_params *cp; + struct tc_ctinfo opt = { + .index = ci->tcf_index, + .refcnt = refcount_read(&ci->tcf_refcnt) - ref, + .bindcnt = atomic_read(&ci->tcf_bindcnt) - bind, + }; + struct tcf_t t; + struct tc_ctinfo_dscp dscpparm; + + spin_lock_bh(&ci->tcf_lock); + cp = rcu_dereference_protected(ci->params, + lockdep_is_held(&ci->tcf_lock)); + opt.action = ci->tcf_action; + + if (nla_put(skb, TCA_CTINFO_ACT, sizeof(opt), &opt)) + goto nla_put_failure; + + if (cp->mode & CTINFO_MODE_SETDSCP) { + dscpparm.mask = cp->dscpmask; + dscpparm.statemask = cp->dscpstatemask; + if (nla_put(skb, TCA_CTINFO_DSCP_PARMS, sizeof(dscpparm), + &dscpparm)) + goto nla_put_failure; + + if (nla_put_flag(skb, TCA_CTINFO_MODE_DSCP)) + goto nla_put_failure; + } + + if (cp->zone) { + if (nla_put_u16(skb, TCA_CTINFO_ZONE, cp->zone)) + goto nla_put_failure; + } + + tcf_tm_dump(&t, &ci->tcf_tm); + if (nla_put_64bit(skb, TCA_CTINFO_TM, sizeof(t), &t, + TCA_CTINFO_PAD)) + goto nla_put_failure; + + spin_unlock_bh(&ci->tcf_lock); + + return skb->len; + +nla_put_failure: + spin_unlock_bh(&ci->tcf_lock); + nlmsg_trim(skb, b); + return -1; +} + +static int tcf_ctinfo_walker(struct net *net, struct sk_buff *skb, + struct netlink_callback *cb, int type, + const struct tc_action_ops *ops, + struct netlink_ext_ack *extack) +{ + struct tc_action_net *tn = net_generic(net, ctinfo_net_id); + + return tcf_generic_walker(tn, skb, cb, type, ops, extack); +} + +static int tcf_ctinfo_search(struct net *net, struct tc_action **a, u32 index) +{ + struct tc_action_net *tn = net_generic(net, ctinfo_net_id); + + return tcf_idr_search(tn, a, index); +} + +static struct tc_action_ops act_ctinfo_ops = { + .kind = "ctinfo", + .id = TCA_ID_CTINFO, + .owner = THIS_MODULE, + .act = tcf_ctinfo_act, + .dump = tcf_ctinfo_dump, + .init = tcf_ctinfo_init, + .walk = tcf_ctinfo_walker, + .lookup = tcf_ctinfo_search, + .size = sizeof(struct tcf_ctinfo), +}; + +static __net_init int ctinfo_init_net(struct net *net) +{ + struct tc_action_net *tn = net_generic(net, ctinfo_net_id); + + return tc_action_net_init(tn, &act_ctinfo_ops); +} + +static void __net_exit ctinfo_exit_net(struct list_head *net_list) +{ + tc_action_net_exit(net_list, ctinfo_net_id); +} + +static struct pernet_operations ctinfo_net_ops = { + .init = ctinfo_init_net, + .exit_batch = ctinfo_exit_net, + .id = &ctinfo_net_id, + .size = sizeof(struct tc_action_net), +}; + +static int __init ctinfo_init_module(void) +{ + return tcf_register_action(&act_ctinfo_ops, &ctinfo_net_ops); +} + +static void __exit ctinfo_cleanup_module(void) +{ + tcf_unregister_action(&act_ctinfo_ops, &ctinfo_net_ops); +} + +module_init(ctinfo_init_module); +module_exit(ctinfo_cleanup_module); +MODULE_AUTHOR("Kevin Darbyshire-Bryant <ldir(a)darbyshire-bryant.me.uk>"); +MODULE_DESCRIPTION("Conntrack mark to DSCP restoring"); +MODULE_LICENSE("GPL"); diff --git a/tools/testing/selftests/tc-testing/config b/tools/testing/selftests/tc-testing/config index 203302065458..9d1fddcfb887 100644 --- a/tools/testing/selftests/tc-testing/config +++ b/tools/testing/selftests/tc-testing/config @@ -37,6 +37,7 @@ CONFIG_NET_ACT_SKBEDIT=m CONFIG_NET_ACT_CSUM=m CONFIG_NET_ACT_VLAN=m CONFIG_NET_ACT_BPF=m +CONFIG_NET_ACT_CONNDSCP=m CONFIG_NET_ACT_CONNMARK=m CONFIG_NET_ACT_SKBMOD=m CONFIG_NET_ACT_IFE=m -- 2.20.1 (Apple Git-117)

5 years, 8 months

5
12
0 0

[PATCH 0/3] x86_64/ftrace: Emulate calls from int3 when patching functions

by Steven Rostedt

[ This is the non-RFC version. It went through and passed all my tests. If there's no objections I'm going to include this in my pull request. I still have patches in my INBOX that may still be included, so I need to run those through my tests as well, so a pull request wont be immediate. ] Nicolai Stange discovered that Live Kernel Patching can have unforseen consequences if tracing is enabled when there are functions that are patched. The reason being, is that Live Kernel patching is built on top of ftrace, which will have the patched functions call the live kernel trampoline directly, and that trampoline will modify the regs->ip address to return to the patched function. But in the transition between changing the call to the customized trampoline, the tracing code is needed to have its handler called an well, so the function fentry location must be changed from calling the live kernel patching trampoline, to the ftrace_reg_caller trampoline which will iterate through all the registered ftrace handlers for that function. During this transition, a break point is added to do the live code modifications. But if that break point is hit, it just skips calling any handler, and makes the call site act as a nop. For tracing, the worse that can happen is that you miss a function being traced, but for live kernel patching the affects are more severe, as the old buggy function is now called. To solve this, an int3_emulate_call() is created for x86_64 to allow ftrace on x86_64 to emulate the call to ftrace_regs_caller() which will make sure all the registered handlers to that function are still called. And this keeps live kernel patching happy! To mimimize the changes, and to avoid controversial patches, this only changes x86_64. Due to the way x86_32 implements the regs->sp the complexity of emulating calls on that platform is too much for stable patches, and live kernel patching does not support x86_32 anyway. Josh Poimboeuf (1): x86_64: Add gap to int3 to allow for call emulation Peter Zijlstra (2): x86_64: Allow breakpoints to emulate call instructions ftrace/x86_64: Emulate call function while updating in breakpoint handler ---- arch/x86/entry/entry_64.S | 18 ++++++++++++++++-- arch/x86/include/asm/text-patching.h | 28 ++++++++++++++++++++++++++++ arch/x86/kernel/ftrace.c | 32 +++++++++++++++++++++++++++----- 3 files changed, 71 insertions(+), 7 deletions(-)

5 years, 8 months

3
6
0 0

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