linux-stable/include/uapi/linux/ptrace.h
Piotr Figiel 90f093fa8e rseq, ptrace: Add PTRACE_GET_RSEQ_CONFIGURATION request
For userspace checkpoint and restore (C/R) a way of getting process state
containing RSEQ configuration is needed.

There are two ways this information is going to be used:
 - to re-enable RSEQ for threads which had it enabled before C/R
 - to detect if a thread was in a critical section during C/R

Since C/R preserves TLS memory and addresses RSEQ ABI will be restored
using the address registered before C/R.

Detection whether the thread is in a critical section during C/R is needed
to enforce behavior of RSEQ abort during C/R. Attaching with ptrace()
before registers are dumped itself doesn't cause RSEQ abort.
Restoring the instruction pointer within the critical section is
problematic because rseq_cs may get cleared before the control is passed
to the migrated application code leading to RSEQ invariants not being
preserved. C/R code will use RSEQ ABI address to find the abort handler
to which the instruction pointer needs to be set.

To achieve above goals expose the RSEQ ABI address and the signature value
with the new ptrace request PTRACE_GET_RSEQ_CONFIGURATION.

This new ptrace request can also be used by debuggers so they are aware
of stops within restartable sequences in progress.

Signed-off-by: Piotr Figiel <figiel@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michal Miroslaw <emmir@google.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/20210226135156.1081606-1-figiel@google.com
2021-03-17 16:15:39 +01:00

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C

/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef _UAPI_LINUX_PTRACE_H
#define _UAPI_LINUX_PTRACE_H
/* ptrace.h */
/* structs and defines to help the user use the ptrace system call. */
/* has the defines to get at the registers. */
#include <linux/types.h>
#define PTRACE_TRACEME 0
#define PTRACE_PEEKTEXT 1
#define PTRACE_PEEKDATA 2
#define PTRACE_PEEKUSR 3
#define PTRACE_POKETEXT 4
#define PTRACE_POKEDATA 5
#define PTRACE_POKEUSR 6
#define PTRACE_CONT 7
#define PTRACE_KILL 8
#define PTRACE_SINGLESTEP 9
#define PTRACE_ATTACH 16
#define PTRACE_DETACH 17
#define PTRACE_SYSCALL 24
/* 0x4200-0x4300 are reserved for architecture-independent additions. */
#define PTRACE_SETOPTIONS 0x4200
#define PTRACE_GETEVENTMSG 0x4201
#define PTRACE_GETSIGINFO 0x4202
#define PTRACE_SETSIGINFO 0x4203
/*
* Generic ptrace interface that exports the architecture specific regsets
* using the corresponding NT_* types (which are also used in the core dump).
* Please note that the NT_PRSTATUS note type in a core dump contains a full
* 'struct elf_prstatus'. But the user_regset for NT_PRSTATUS contains just the
* elf_gregset_t that is the pr_reg field of 'struct elf_prstatus'. For all the
* other user_regset flavors, the user_regset layout and the ELF core dump note
* payload are exactly the same layout.
*
* This interface usage is as follows:
* struct iovec iov = { buf, len};
*
* ret = ptrace(PTRACE_GETREGSET/PTRACE_SETREGSET, pid, NT_XXX_TYPE, &iov);
*
* On the successful completion, iov.len will be updated by the kernel,
* specifying how much the kernel has written/read to/from the user's iov.buf.
*/
#define PTRACE_GETREGSET 0x4204
#define PTRACE_SETREGSET 0x4205
#define PTRACE_SEIZE 0x4206
#define PTRACE_INTERRUPT 0x4207
#define PTRACE_LISTEN 0x4208
#define PTRACE_PEEKSIGINFO 0x4209
struct ptrace_peeksiginfo_args {
__u64 off; /* from which siginfo to start */
__u32 flags;
__s32 nr; /* how may siginfos to take */
};
#define PTRACE_GETSIGMASK 0x420a
#define PTRACE_SETSIGMASK 0x420b
#define PTRACE_SECCOMP_GET_FILTER 0x420c
#define PTRACE_SECCOMP_GET_METADATA 0x420d
struct seccomp_metadata {
__u64 filter_off; /* Input: which filter */
__u64 flags; /* Output: filter's flags */
};
#define PTRACE_GET_SYSCALL_INFO 0x420e
#define PTRACE_SYSCALL_INFO_NONE 0
#define PTRACE_SYSCALL_INFO_ENTRY 1
#define PTRACE_SYSCALL_INFO_EXIT 2
#define PTRACE_SYSCALL_INFO_SECCOMP 3
struct ptrace_syscall_info {
__u8 op; /* PTRACE_SYSCALL_INFO_* */
__u8 pad[3];
__u32 arch;
__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;
};
};
#define PTRACE_GET_RSEQ_CONFIGURATION 0x420f
struct ptrace_rseq_configuration {
__u64 rseq_abi_pointer;
__u32 rseq_abi_size;
__u32 signature;
__u32 flags;
__u32 pad;
};
/*
* These values are stored in task->ptrace_message
* by tracehook_report_syscall_* to describe the current syscall-stop.
*/
#define PTRACE_EVENTMSG_SYSCALL_ENTRY 1
#define PTRACE_EVENTMSG_SYSCALL_EXIT 2
/* Read signals from a shared (process wide) queue */
#define PTRACE_PEEKSIGINFO_SHARED (1 << 0)
/* Wait extended result codes for the above trace options. */
#define PTRACE_EVENT_FORK 1
#define PTRACE_EVENT_VFORK 2
#define PTRACE_EVENT_CLONE 3
#define PTRACE_EVENT_EXEC 4
#define PTRACE_EVENT_VFORK_DONE 5
#define PTRACE_EVENT_EXIT 6
#define PTRACE_EVENT_SECCOMP 7
/* Extended result codes which enabled by means other than options. */
#define PTRACE_EVENT_STOP 128
/* Options set using PTRACE_SETOPTIONS or using PTRACE_SEIZE @data param */
#define PTRACE_O_TRACESYSGOOD 1
#define PTRACE_O_TRACEFORK (1 << PTRACE_EVENT_FORK)
#define PTRACE_O_TRACEVFORK (1 << PTRACE_EVENT_VFORK)
#define PTRACE_O_TRACECLONE (1 << PTRACE_EVENT_CLONE)
#define PTRACE_O_TRACEEXEC (1 << PTRACE_EVENT_EXEC)
#define PTRACE_O_TRACEVFORKDONE (1 << PTRACE_EVENT_VFORK_DONE)
#define PTRACE_O_TRACEEXIT (1 << PTRACE_EVENT_EXIT)
#define PTRACE_O_TRACESECCOMP (1 << PTRACE_EVENT_SECCOMP)
/* eventless options */
#define PTRACE_O_EXITKILL (1 << 20)
#define PTRACE_O_SUSPEND_SECCOMP (1 << 21)
#define PTRACE_O_MASK (\
0x000000ff | PTRACE_O_EXITKILL | PTRACE_O_SUSPEND_SECCOMP)
#include <asm/ptrace.h>
#endif /* _UAPI_LINUX_PTRACE_H */