5521eb4bca
This is a patch that adds support for PTRACE_SYSEMU ptrace request in PowerPC architecture. When ptrace(PTRACE_SYSEMU, ...) request is called, it will be handled by the arch independent function ptrace_resume(), which will tag the task with the TIF_SYSCALL_EMU flag. This flag needs to be handled from a platform dependent point of view, which is what this patch does. This patch adds this task's flag as part of the _TIF_SYSCALL_DOTRACE, which is the MACRO that is used to trace syscalls at entrance/exit. Since TIF_SYSCALL_EMU is now part of _TIF_SYSCALL_DOTRACE, if the task has _TIF_SYSCALL_DOTRACE set, it will hit do_syscall_trace_enter() at syscall entrance and do_syscall_trace_leave() at syscall leave. do_syscall_trace_enter() needs to handle the TIF_SYSCALL_EMU flag properly, which will interrupt the syscall executing if TIF_SYSCALL_EMU is set. The output values should not be changed, i.e. the return value (r3) should contain the original syscall argument on exit. With this flag set, the syscall is not executed fundamentally, because do_syscall_trace_enter() is returning -1 which is bigger than NR_syscall, thus, skipping the syscall execution and exiting userspace. Signed-off-by: Breno Leitao <leitao@debian.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
172 lines
5.5 KiB
C
172 lines
5.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/* thread_info.h: PowerPC low-level thread information
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* adapted from the i386 version by Paul Mackerras
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*
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* Copyright (C) 2002 David Howells (dhowells@redhat.com)
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* - Incorporating suggestions made by Linus Torvalds and Dave Miller
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*/
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#ifndef _ASM_POWERPC_THREAD_INFO_H
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#define _ASM_POWERPC_THREAD_INFO_H
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#include <asm/asm-const.h>
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#ifdef __KERNEL__
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#define THREAD_SHIFT CONFIG_THREAD_SHIFT
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#define THREAD_SIZE (1 << THREAD_SHIFT)
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#ifdef CONFIG_PPC64
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#define CURRENT_THREAD_INFO(dest, sp) stringify_in_c(clrrdi dest, sp, THREAD_SHIFT)
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#else
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#define CURRENT_THREAD_INFO(dest, sp) stringify_in_c(rlwinm dest, sp, 0, 0, 31-THREAD_SHIFT)
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#endif
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#ifndef __ASSEMBLY__
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#include <linux/cache.h>
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#include <asm/processor.h>
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#include <asm/page.h>
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#include <asm/accounting.h>
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/*
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* low level task data.
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*/
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struct thread_info {
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struct task_struct *task; /* main task structure */
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int cpu; /* cpu we're on */
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int preempt_count; /* 0 => preemptable,
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<0 => BUG */
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unsigned long local_flags; /* private flags for thread */
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#ifdef CONFIG_LIVEPATCH
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unsigned long *livepatch_sp;
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#endif
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#if defined(CONFIG_VIRT_CPU_ACCOUNTING_NATIVE) && defined(CONFIG_PPC32)
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struct cpu_accounting_data accounting;
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#endif
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/* low level flags - has atomic operations done on it */
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unsigned long flags ____cacheline_aligned_in_smp;
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};
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/*
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* macros/functions for gaining access to the thread information structure
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*/
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#define INIT_THREAD_INFO(tsk) \
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{ \
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.task = &tsk, \
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.cpu = 0, \
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.preempt_count = INIT_PREEMPT_COUNT, \
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.flags = 0, \
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}
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#define THREAD_SIZE_ORDER (THREAD_SHIFT - PAGE_SHIFT)
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/* how to get the thread information struct from C */
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static inline struct thread_info *current_thread_info(void)
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{
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unsigned long val;
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asm (CURRENT_THREAD_INFO(%0,1) : "=r" (val));
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return (struct thread_info *)val;
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}
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extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
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#endif /* __ASSEMBLY__ */
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/*
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* thread information flag bit numbers
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*/
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#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
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#define TIF_SIGPENDING 1 /* signal pending */
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#define TIF_NEED_RESCHED 2 /* rescheduling necessary */
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#define TIF_FSCHECK 3 /* Check FS is USER_DS on return */
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#define TIF_SYSCALL_EMU 4 /* syscall emulation active */
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#define TIF_RESTORE_TM 5 /* need to restore TM FP/VEC/VSX */
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#define TIF_PATCH_PENDING 6 /* pending live patching update */
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#define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
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#define TIF_SINGLESTEP 8 /* singlestepping active */
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#define TIF_NOHZ 9 /* in adaptive nohz mode */
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#define TIF_SECCOMP 10 /* secure computing */
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#define TIF_RESTOREALL 11 /* Restore all regs (implies NOERROR) */
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#define TIF_NOERROR 12 /* Force successful syscall return */
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#define TIF_NOTIFY_RESUME 13 /* callback before returning to user */
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#define TIF_UPROBE 14 /* breakpointed or single-stepping */
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#define TIF_SYSCALL_TRACEPOINT 15 /* syscall tracepoint instrumentation */
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#define TIF_EMULATE_STACK_STORE 16 /* Is an instruction emulation
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for stack store? */
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#define TIF_MEMDIE 17 /* is terminating due to OOM killer */
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#if defined(CONFIG_PPC64)
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#define TIF_ELF2ABI 18 /* function descriptors must die! */
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#endif
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#define TIF_POLLING_NRFLAG 19 /* true if poll_idle() is polling TIF_NEED_RESCHED */
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#define TIF_32BIT 20 /* 32 bit binary */
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/* as above, but as bit values */
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#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
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#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
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#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
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#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
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#define _TIF_32BIT (1<<TIF_32BIT)
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#define _TIF_RESTORE_TM (1<<TIF_RESTORE_TM)
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#define _TIF_PATCH_PENDING (1<<TIF_PATCH_PENDING)
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#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
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#define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP)
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#define _TIF_SECCOMP (1<<TIF_SECCOMP)
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#define _TIF_RESTOREALL (1<<TIF_RESTOREALL)
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#define _TIF_NOERROR (1<<TIF_NOERROR)
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#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
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#define _TIF_UPROBE (1<<TIF_UPROBE)
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#define _TIF_SYSCALL_TRACEPOINT (1<<TIF_SYSCALL_TRACEPOINT)
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#define _TIF_EMULATE_STACK_STORE (1<<TIF_EMULATE_STACK_STORE)
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#define _TIF_NOHZ (1<<TIF_NOHZ)
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#define _TIF_FSCHECK (1<<TIF_FSCHECK)
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#define _TIF_SYSCALL_EMU (1<<TIF_SYSCALL_EMU)
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#define _TIF_SYSCALL_DOTRACE (_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
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_TIF_SECCOMP | _TIF_SYSCALL_TRACEPOINT | \
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_TIF_NOHZ | _TIF_SYSCALL_EMU)
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#define _TIF_USER_WORK_MASK (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
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_TIF_NOTIFY_RESUME | _TIF_UPROBE | \
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_TIF_RESTORE_TM | _TIF_PATCH_PENDING | \
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_TIF_FSCHECK)
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#define _TIF_PERSYSCALL_MASK (_TIF_RESTOREALL|_TIF_NOERROR)
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/* Bits in local_flags */
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/* Don't move TLF_NAPPING without adjusting the code in entry_32.S */
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#define TLF_NAPPING 0 /* idle thread enabled NAP mode */
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#define TLF_SLEEPING 1 /* suspend code enabled SLEEP mode */
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#define TLF_LAZY_MMU 3 /* tlb_batch is active */
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#define TLF_RUNLATCH 4 /* Is the runlatch enabled? */
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#define _TLF_NAPPING (1 << TLF_NAPPING)
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#define _TLF_SLEEPING (1 << TLF_SLEEPING)
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#define _TLF_LAZY_MMU (1 << TLF_LAZY_MMU)
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#define _TLF_RUNLATCH (1 << TLF_RUNLATCH)
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#ifndef __ASSEMBLY__
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static inline bool test_thread_local_flags(unsigned int flags)
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{
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struct thread_info *ti = current_thread_info();
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return (ti->local_flags & flags) != 0;
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}
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#ifdef CONFIG_PPC64
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#define is_32bit_task() (test_thread_flag(TIF_32BIT))
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#else
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#define is_32bit_task() (1)
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#endif
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#if defined(CONFIG_PPC64)
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#define is_elf2_task() (test_thread_flag(TIF_ELF2ABI))
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#else
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#define is_elf2_task() (0)
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#endif
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#endif /* !__ASSEMBLY__ */
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#endif /* __KERNEL__ */
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#endif /* _ASM_POWERPC_THREAD_INFO_H */
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