kernel.git/arch/x86/kernel/kprobes, branch linux-5.12.y

x86/kprobes: Fix to check non boostable prefixes correctly

2021-05-14T08:52:37Z

[ Upstream commit 6dd3b8c9f58816a1354be39559f630cd1bd12159 ] There are 2 bugs in the can_boost() function because of using x86 insn decoder. Since the insn->opcode never has a prefix byte, it can not find CS override prefix in it. And the insn->attr is the attribute of the opcode, thus inat_is_address_size_prefix( insn->attr) always returns false. Fix those by checking each prefix bytes with for_each_insn_prefix loop and getting the correct attribute for each prefix byte. Also, this removes unlikely, because this is a slow path. Fixes: a8d11cd0714f ("kprobes/x86: Consolidate insn decoder users for copying code") Signed-off-by: Masami Hiramatsu Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/161666691162.1120877.2808435205294352583.stgit@devnote2 Signed-off-by: Sasha Levin

x86/kprobes: Retrieve correct opcode for group instruction

2021-05-14T08:52:36Z

[ Upstream commit d60ad3d46f1d04a282c56159f1deb675c12733fd ] Since the opcodes start from 0xff are group5 instruction group which is not 2 bytes opcode but the extended opcode determined by the MOD/RM byte. The commit abd82e533d88 ("x86/kprobes: Do not decode opcode in resume_execution()") used insn->opcode.bytes[1], but that is not correct. We have to refer the insn->modrm.bytes[1] instead. Fixes: abd82e533d88 ("x86/kprobes: Do not decode opcode in resume_execution()") Signed-off-by: Masami Hiramatsu Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/161469872400.49483.18214724458034233166.stgit@devnote2 Signed-off-by: Sasha Levin

ftrace: Fix spelling mistake "disabed" -> "disabled"

2021-03-17T04:19:40Z

There is a spelling mistake in a comment, fix it. Signed-off-by: Colin Ian King Signed-off-by: Palmer Dabbelt

x86/kprobes: Do not decode opcode in resume_execution()

2021-01-05T14:42:30Z

Currently, kprobes decodes the opcode right after single-stepping in resume_execution(). But the opcode was already decoded while preparing arch_specific_insn in arch_copy_kprobe(). Decode the opcode in arch_copy_kprobe() instead of in resume_execution() and set some flags which classify the opcode for the resuming process. [ bp: Massage commit message. ] Signed-off-by: Masami Hiramatsu Signed-off-by: Borislav Petkov Acked-by: Steven Rostedt (VMware) Link: https://lkml.kernel.org/r/160830072561.349576.3014979564448023213.stgit@devnote2

Merge tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2020-12-17T21:22:17Z

Pull tracing updates from Steven Rostedt: "The major update to this release is that there's a new arch config option called CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS. Currently, only x86_64 enables it. All the ftrace callbacks now take a struct ftrace_regs instead of a struct pt_regs. If the architecture has HAVE_DYNAMIC_FTRACE_WITH_ARGS enabled, then the ftrace_regs will have enough information to read the arguments of the function being traced, as well as access to the stack pointer. This way, if a user (like live kernel patching) only cares about the arguments, then it can avoid using the heavier weight "regs" callback, that puts in enough information in the struct ftrace_regs to simulate a breakpoint exception (needed for kprobes). A new config option that audits the timestamps of the ftrace ring buffer at most every event recorded. Ftrace recursion protection has been cleaned up to move the protection to the callback itself (this saves on an extra function call for those callbacks). Perf now handles its own RCU protection and does not depend on ftrace to do it for it (saving on that extra function call). New debug option to add "recursed_functions" file to tracefs that lists all the places that triggered the recursion protection of the function tracer. This will show where things need to be fixed as recursion slows down the function tracer. The eval enum mapping updates done at boot up are now offloaded to a work queue, as it caused a noticeable pause on slow embedded boards. Various clean ups and last minute fixes" * tag 'trace-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (33 commits) tracing: Offload eval map updates to a work queue Revert: "ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS" ring-buffer: Add rb_check_bpage in __rb_allocate_pages ring-buffer: Fix two typos in comments tracing: Drop unneeded assignment in ring_buffer_resize() tracing: Disable ftrace selftests when any tracer is running seq_buf: Avoid type mismatch for seq_buf_init ring-buffer: Fix a typo in function description ring-buffer: Remove obsolete rb_event_is_commit() ring-buffer: Add test to validate the time stamp deltas ftrace/documentation: Fix RST C code blocks tracing: Clean up after filter logic rewriting tracing: Remove the useless value assignment in test_create_synth_event() livepatch: Use the default ftrace_ops instead of REGS when ARGS is available ftrace/x86: Allow for arguments to be passed in to ftrace_regs by default ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs MAINTAINERS: assign ./fs/tracefs to TRACING tracing: Fix some typos in comments ftrace: Remove unused varible 'ret' ring-buffer: Add recording of ring buffer recursion into recursed_functions ...

Merge tag 'perf-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2020-12-15T01:34:12Z

Pull perf updates from Thomas Gleixner: "Core: - Better handling of page table leaves on archictectures which have architectures have non-pagetable aligned huge/large pages. For such architectures a leaf can actually be part of a larger entry. - Prevent a deadlock vs exec_update_mutex Architectures: - The related updates for page size calculation of leaf entries - The usual churn to support new CPUs - Small fixes and improvements all over the place" * tag 'perf-core-2020-12-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) perf/x86/intel: Add Tremont Topdown support uprobes/x86: Fix fall-through warnings for Clang perf/x86: Fix fall-through warnings for Clang kprobes/x86: Fix fall-through warnings for Clang perf/x86/intel/lbr: Fix the return type of get_lbr_cycles() perf/x86/intel: Fix rtm_abort_event encoding on Ice Lake x86/kprobes: Restore BTF if the single-stepping is cancelled perf: Break deadlock involving exec_update_mutex sparc64/mm: Implement pXX_leaf_size() support powerpc/8xx: Implement pXX_leaf_size() support arm64/mm: Implement pXX_leaf_size() support perf/core: Fix arch_perf_get_page_size() mm: Introduce pXX_leaf_size() mm/gup: Provide gup_get_pte() more generic perf/x86/intel: Add event constraint for CYCLE_ACTIVITY.STALLS_MEM_ANY perf/x86/intel/uncore: Add Rocket Lake support perf/x86/msr: Add Rocket Lake CPU support perf/x86/cstate: Add Rocket Lake CPU support perf/x86/intel: Add Rocket Lake CPU support perf,mm: Handle non-page-table-aligned hugetlbfs ...

x86/kprobes: Fix optprobe to detect INT3 padding correctly

2020-12-12T14:25:17Z

Commit 7705dc855797 ("x86/vmlinux: Use INT3 instead of NOP for linker fill bytes") changed the padding bytes between functions from NOP to INT3. However, when optprobe decodes a target function it finds INT3 and gives up the jump optimization. Instead of giving up any INT3 detection, check whether the rest of the bytes to the end of the function are INT3. If all of them are INT3, those come from the linker. In that case, continue the optprobe jump optimization. [ bp: Massage commit message. ] Fixes: 7705dc855797 ("x86/vmlinux: Use INT3 instead of NOP for linker fill bytes") Reported-by: Adam Zabrocki Signed-off-by: Masami Hiramatsu Signed-off-by: Borislav Petkov Reviewed-by: Steven Rostedt (VMware) Reviewed-by: Kees Cook Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/160767025681.3880685.16021570341428835411.stgit@devnote2

kprobes/x86: Fix fall-through warnings for Clang

2020-12-09T16:08:58Z

In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning by explicitly adding a break statement instead of just letting the code fall through to the next case. Signed-off-by: Gustavo A. R. Silva Signed-off-by: Peter Zijlstra (Intel) Link: https://github.com/KSPP/linux/issues/115

x86/kprobes: Restore BTF if the single-stepping is cancelled

2020-12-09T16:08:57Z

Fix to restore BTF if single-stepping causes a page fault and it is cancelled. Usually the BTF flag was restored when the single stepping is done (in resume_execution()). However, if a page fault happens on the single stepping instruction, the fault handler is invoked and the single stepping is cancelled. Thus, the BTF flag is not restored. Fixes: 1ecc798c6764 ("x86: debugctlmsr kprobes") Signed-off-by: Masami Hiramatsu Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/160389546985.106936.12727996109376240993.stgit@devnote2

ftrace: Have the callbacks receive a struct ftrace_regs instead of pt_regs

2020-11-13T17:14:55Z

In preparation to have arguments of a function passed to callbacks attached to functions as default, change the default callback prototype to receive a struct ftrace_regs as the forth parameter instead of a pt_regs. For callbacks that set the FL_SAVE_REGS flag in their ftrace_ops flags, they will now need to get the pt_regs via a ftrace_get_regs() helper call. If this is called by a callback that their ftrace_ops did not have a FL_SAVE_REGS flag set, it that helper function will return NULL. This will allow the ftrace_regs to hold enough just to get the parameters and stack pointer, but without the worry that callbacks may have a pt_regs that is not completely filled. Acked-by: Peter Zijlstra (Intel) Reviewed-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)