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Diffstat (limited to 'arch/powerpc/kernel/ptrace/ptrace.c')
-rw-r--r--arch/powerpc/kernel/ptrace/ptrace.c447
1 files changed, 447 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/ptrace/ptrace.c b/arch/powerpc/kernel/ptrace/ptrace.c
new file mode 100644
index 000000000000..727ed4a14545
--- /dev/null
+++ b/arch/powerpc/kernel/ptrace/ptrace.c
@@ -0,0 +1,447 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PowerPC version
+ * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ * Derived from "arch/m68k/kernel/ptrace.c"
+ * Copyright (C) 1994 by Hamish Macdonald
+ * Taken from linux/kernel/ptrace.c and modified for M680x0.
+ * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
+ *
+ * Modified by Cort Dougan (cort@hq.fsmlabs.com)
+ * and Paul Mackerras (paulus@samba.org).
+ */
+
+#include <linux/regset.h>
+#include <linux/ptrace.h>
+#include <linux/audit.h>
+#include <linux/context_tracking.h>
+#include <linux/syscalls.h>
+
+#include <asm/switch_to.h>
+#include <asm/debug.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/syscalls.h>
+
+#include "ptrace-decl.h"
+
+/*
+ * Called by kernel/ptrace.c when detaching..
+ *
+ * Make sure single step bits etc are not set.
+ */
+void ptrace_disable(struct task_struct *child)
+{
+ /* make sure the single step bit is not set. */
+ user_disable_single_step(child);
+}
+
+long arch_ptrace(struct task_struct *child, long request,
+ unsigned long addr, unsigned long data)
+{
+ int ret = -EPERM;
+ void __user *datavp = (void __user *) data;
+ unsigned long __user *datalp = datavp;
+
+ switch (request) {
+ /* read the word at location addr in the USER area. */
+ case PTRACE_PEEKUSR: {
+ unsigned long index, tmp;
+
+ ret = -EIO;
+ /* convert to index and check */
+ index = addr / sizeof(long);
+ if ((addr & (sizeof(long) - 1)) || !child->thread.regs)
+ break;
+
+ if (index < PT_FPR0)
+ ret = ptrace_get_reg(child, (int) index, &tmp);
+ else
+ ret = ptrace_get_fpr(child, index, &tmp);
+
+ if (ret)
+ break;
+ ret = put_user(tmp, datalp);
+ break;
+ }
+
+ /* write the word at location addr in the USER area */
+ case PTRACE_POKEUSR: {
+ unsigned long index;
+
+ ret = -EIO;
+ /* convert to index and check */
+ index = addr / sizeof(long);
+ if ((addr & (sizeof(long) - 1)) || !child->thread.regs)
+ break;
+
+ if (index < PT_FPR0)
+ ret = ptrace_put_reg(child, index, data);
+ else
+ ret = ptrace_put_fpr(child, index, data);
+ break;
+ }
+
+ case PPC_PTRACE_GETHWDBGINFO: {
+ struct ppc_debug_info dbginfo;
+
+ ppc_gethwdinfo(&dbginfo);
+
+ if (copy_to_user(datavp, &dbginfo,
+ sizeof(struct ppc_debug_info)))
+ return -EFAULT;
+ return 0;
+ }
+
+ case PPC_PTRACE_SETHWDEBUG: {
+ struct ppc_hw_breakpoint bp_info;
+
+ if (copy_from_user(&bp_info, datavp,
+ sizeof(struct ppc_hw_breakpoint)))
+ return -EFAULT;
+ return ppc_set_hwdebug(child, &bp_info);
+ }
+
+ case PPC_PTRACE_DELHWDEBUG: {
+ ret = ppc_del_hwdebug(child, data);
+ break;
+ }
+
+ case PTRACE_GET_DEBUGREG:
+ ret = ptrace_get_debugreg(child, addr, datalp);
+ break;
+
+ case PTRACE_SET_DEBUGREG:
+ ret = ptrace_set_debugreg(child, addr, data);
+ break;
+
+#ifdef CONFIG_PPC64
+ case PTRACE_GETREGS64:
+#endif
+ case PTRACE_GETREGS: /* Get all pt_regs from the child. */
+ return copy_regset_to_user(child, &user_ppc_native_view,
+ REGSET_GPR,
+ 0, sizeof(struct user_pt_regs),
+ datavp);
+
+#ifdef CONFIG_PPC64
+ case PTRACE_SETREGS64:
+#endif
+ case PTRACE_SETREGS: /* Set all gp regs in the child. */
+ return copy_regset_from_user(child, &user_ppc_native_view,
+ REGSET_GPR,
+ 0, sizeof(struct user_pt_regs),
+ datavp);
+
+ case PTRACE_GETFPREGS: /* Get the child FPU state (FPR0...31 + FPSCR) */
+ return copy_regset_to_user(child, &user_ppc_native_view,
+ REGSET_FPR,
+ 0, sizeof(elf_fpregset_t),
+ datavp);
+
+ case PTRACE_SETFPREGS: /* Set the child FPU state (FPR0...31 + FPSCR) */
+ return copy_regset_from_user(child, &user_ppc_native_view,
+ REGSET_FPR,
+ 0, sizeof(elf_fpregset_t),
+ datavp);
+
+#ifdef CONFIG_ALTIVEC
+ case PTRACE_GETVRREGS:
+ return copy_regset_to_user(child, &user_ppc_native_view,
+ REGSET_VMX,
+ 0, (33 * sizeof(vector128) +
+ sizeof(u32)),
+ datavp);
+
+ case PTRACE_SETVRREGS:
+ return copy_regset_from_user(child, &user_ppc_native_view,
+ REGSET_VMX,
+ 0, (33 * sizeof(vector128) +
+ sizeof(u32)),
+ datavp);
+#endif
+#ifdef CONFIG_VSX
+ case PTRACE_GETVSRREGS:
+ return copy_regset_to_user(child, &user_ppc_native_view,
+ REGSET_VSX,
+ 0, 32 * sizeof(double),
+ datavp);
+
+ case PTRACE_SETVSRREGS:
+ return copy_regset_from_user(child, &user_ppc_native_view,
+ REGSET_VSX,
+ 0, 32 * sizeof(double),
+ datavp);
+#endif
+#ifdef CONFIG_SPE
+ case PTRACE_GETEVRREGS:
+ /* Get the child spe register state. */
+ return copy_regset_to_user(child, &user_ppc_native_view,
+ REGSET_SPE, 0, 35 * sizeof(u32),
+ datavp);
+
+ case PTRACE_SETEVRREGS:
+ /* Set the child spe register state. */
+ return copy_regset_from_user(child, &user_ppc_native_view,
+ REGSET_SPE, 0, 35 * sizeof(u32),
+ datavp);
+#endif
+
+ default:
+ ret = ptrace_request(child, request, addr, data);
+ break;
+ }
+ return ret;
+}
+
+#ifdef CONFIG_SECCOMP
+static int do_seccomp(struct pt_regs *regs)
+{
+ if (!test_thread_flag(TIF_SECCOMP))
+ return 0;
+
+ /*
+ * The ABI we present to seccomp tracers is that r3 contains
+ * the syscall return value and orig_gpr3 contains the first
+ * syscall parameter. This is different to the ptrace ABI where
+ * both r3 and orig_gpr3 contain the first syscall parameter.
+ */
+ regs->gpr[3] = -ENOSYS;
+
+ /*
+ * We use the __ version here because we have already checked
+ * TIF_SECCOMP. If this fails, there is nothing left to do, we
+ * have already loaded -ENOSYS into r3, or seccomp has put
+ * something else in r3 (via SECCOMP_RET_ERRNO/TRACE).
+ */
+ if (__secure_computing(NULL))
+ return -1;
+
+ /*
+ * The syscall was allowed by seccomp, restore the register
+ * state to what audit expects.
+ * Note that we use orig_gpr3, which means a seccomp tracer can
+ * modify the first syscall parameter (in orig_gpr3) and also
+ * allow the syscall to proceed.
+ */
+ regs->gpr[3] = regs->orig_gpr3;
+
+ return 0;
+}
+#else
+static inline int do_seccomp(struct pt_regs *regs) { return 0; }
+#endif /* CONFIG_SECCOMP */
+
+/**
+ * do_syscall_trace_enter() - Do syscall tracing on kernel entry.
+ * @regs: the pt_regs of the task to trace (current)
+ *
+ * Performs various types of tracing on syscall entry. This includes seccomp,
+ * ptrace, syscall tracepoints and audit.
+ *
+ * The pt_regs are potentially visible to userspace via ptrace, so their
+ * contents is ABI.
+ *
+ * One or more of the tracers may modify the contents of pt_regs, in particular
+ * to modify arguments or even the syscall number itself.
+ *
+ * It's also possible that a tracer can choose to reject the system call. In
+ * that case this function will return an illegal syscall number, and will put
+ * an appropriate return value in regs->r3.
+ *
+ * Return: the (possibly changed) syscall number.
+ */
+long do_syscall_trace_enter(struct pt_regs *regs)
+{
+ u32 flags;
+
+ flags = read_thread_flags() & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE);
+
+ if (flags) {
+ int rc = ptrace_report_syscall_entry(regs);
+
+ if (unlikely(flags & _TIF_SYSCALL_EMU)) {
+ /*
+ * A nonzero return code from
+ * ptrace_report_syscall_entry() tells us to prevent
+ * the syscall execution, but we are not going to
+ * execute it anyway.
+ *
+ * Returning -1 will skip the syscall execution. We want
+ * to avoid clobbering any registers, so we don't goto
+ * the skip label below.
+ */
+ return -1;
+ }
+
+ if (rc) {
+ /*
+ * The tracer decided to abort the syscall. Note that
+ * the tracer may also just change regs->gpr[0] to an
+ * invalid syscall number, that is handled below on the
+ * exit path.
+ */
+ goto skip;
+ }
+ }
+
+ /* Run seccomp after ptrace; allow it to set gpr[3]. */
+ if (do_seccomp(regs))
+ return -1;
+
+ /* Avoid trace and audit when syscall is invalid. */
+ if (regs->gpr[0] >= NR_syscalls)
+ goto skip;
+
+ if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
+ trace_sys_enter(regs, regs->gpr[0]);
+
+ if (!is_32bit_task())
+ audit_syscall_entry(regs->gpr[0], regs->gpr[3], regs->gpr[4],
+ regs->gpr[5], regs->gpr[6]);
+ else
+ audit_syscall_entry(regs->gpr[0],
+ regs->gpr[3] & 0xffffffff,
+ regs->gpr[4] & 0xffffffff,
+ regs->gpr[5] & 0xffffffff,
+ regs->gpr[6] & 0xffffffff);
+
+ /* Return the possibly modified but valid syscall number */
+ return regs->gpr[0];
+
+skip:
+ /*
+ * If we are aborting explicitly, or if the syscall number is
+ * now invalid, set the return value to -ENOSYS.
+ */
+ regs->gpr[3] = -ENOSYS;
+ return -1;
+}
+
+void do_syscall_trace_leave(struct pt_regs *regs)
+{
+ int step;
+
+ audit_syscall_exit(regs);
+
+ if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
+ trace_sys_exit(regs, regs->result);
+
+ step = test_thread_flag(TIF_SINGLESTEP);
+ if (step || test_thread_flag(TIF_SYSCALL_TRACE))
+ ptrace_report_syscall_exit(regs, step);
+}
+
+void __init pt_regs_check(void);
+
+/*
+ * Dummy function, its purpose is to break the build if struct pt_regs and
+ * struct user_pt_regs don't match.
+ */
+void __init pt_regs_check(void)
+{
+ BUILD_BUG_ON(offsetof(struct pt_regs, gpr) !=
+ offsetof(struct user_pt_regs, gpr));
+ BUILD_BUG_ON(offsetof(struct pt_regs, nip) !=
+ offsetof(struct user_pt_regs, nip));
+ BUILD_BUG_ON(offsetof(struct pt_regs, msr) !=
+ offsetof(struct user_pt_regs, msr));
+ BUILD_BUG_ON(offsetof(struct pt_regs, orig_gpr3) !=
+ offsetof(struct user_pt_regs, orig_gpr3));
+ BUILD_BUG_ON(offsetof(struct pt_regs, ctr) !=
+ offsetof(struct user_pt_regs, ctr));
+ BUILD_BUG_ON(offsetof(struct pt_regs, link) !=
+ offsetof(struct user_pt_regs, link));
+ BUILD_BUG_ON(offsetof(struct pt_regs, xer) !=
+ offsetof(struct user_pt_regs, xer));
+ BUILD_BUG_ON(offsetof(struct pt_regs, ccr) !=
+ offsetof(struct user_pt_regs, ccr));
+#ifdef __powerpc64__
+ BUILD_BUG_ON(offsetof(struct pt_regs, softe) !=
+ offsetof(struct user_pt_regs, softe));
+#else
+ BUILD_BUG_ON(offsetof(struct pt_regs, mq) !=
+ offsetof(struct user_pt_regs, mq));
+#endif
+ BUILD_BUG_ON(offsetof(struct pt_regs, trap) !=
+ offsetof(struct user_pt_regs, trap));
+ BUILD_BUG_ON(offsetof(struct pt_regs, dar) !=
+ offsetof(struct user_pt_regs, dar));
+ BUILD_BUG_ON(offsetof(struct pt_regs, dear) !=
+ offsetof(struct user_pt_regs, dar));
+ BUILD_BUG_ON(offsetof(struct pt_regs, dsisr) !=
+ offsetof(struct user_pt_regs, dsisr));
+ BUILD_BUG_ON(offsetof(struct pt_regs, esr) !=
+ offsetof(struct user_pt_regs, dsisr));
+ BUILD_BUG_ON(offsetof(struct pt_regs, result) !=
+ offsetof(struct user_pt_regs, result));
+
+ BUILD_BUG_ON(sizeof(struct user_pt_regs) > sizeof(struct pt_regs));
+
+ // Now check that the pt_regs offsets match the uapi #defines
+ #define CHECK_REG(_pt, _reg) \
+ BUILD_BUG_ON(_pt != (offsetof(struct user_pt_regs, _reg) / \
+ sizeof(unsigned long)));
+
+ CHECK_REG(PT_R0, gpr[0]);
+ CHECK_REG(PT_R1, gpr[1]);
+ CHECK_REG(PT_R2, gpr[2]);
+ CHECK_REG(PT_R3, gpr[3]);
+ CHECK_REG(PT_R4, gpr[4]);
+ CHECK_REG(PT_R5, gpr[5]);
+ CHECK_REG(PT_R6, gpr[6]);
+ CHECK_REG(PT_R7, gpr[7]);
+ CHECK_REG(PT_R8, gpr[8]);
+ CHECK_REG(PT_R9, gpr[9]);
+ CHECK_REG(PT_R10, gpr[10]);
+ CHECK_REG(PT_R11, gpr[11]);
+ CHECK_REG(PT_R12, gpr[12]);
+ CHECK_REG(PT_R13, gpr[13]);
+ CHECK_REG(PT_R14, gpr[14]);
+ CHECK_REG(PT_R15, gpr[15]);
+ CHECK_REG(PT_R16, gpr[16]);
+ CHECK_REG(PT_R17, gpr[17]);
+ CHECK_REG(PT_R18, gpr[18]);
+ CHECK_REG(PT_R19, gpr[19]);
+ CHECK_REG(PT_R20, gpr[20]);
+ CHECK_REG(PT_R21, gpr[21]);
+ CHECK_REG(PT_R22, gpr[22]);
+ CHECK_REG(PT_R23, gpr[23]);
+ CHECK_REG(PT_R24, gpr[24]);
+ CHECK_REG(PT_R25, gpr[25]);
+ CHECK_REG(PT_R26, gpr[26]);
+ CHECK_REG(PT_R27, gpr[27]);
+ CHECK_REG(PT_R28, gpr[28]);
+ CHECK_REG(PT_R29, gpr[29]);
+ CHECK_REG(PT_R30, gpr[30]);
+ CHECK_REG(PT_R31, gpr[31]);
+ CHECK_REG(PT_NIP, nip);
+ CHECK_REG(PT_MSR, msr);
+ CHECK_REG(PT_ORIG_R3, orig_gpr3);
+ CHECK_REG(PT_CTR, ctr);
+ CHECK_REG(PT_LNK, link);
+ CHECK_REG(PT_XER, xer);
+ CHECK_REG(PT_CCR, ccr);
+#ifdef CONFIG_PPC64
+ CHECK_REG(PT_SOFTE, softe);
+#else
+ CHECK_REG(PT_MQ, mq);
+#endif
+ CHECK_REG(PT_TRAP, trap);
+ CHECK_REG(PT_DAR, dar);
+ CHECK_REG(PT_DSISR, dsisr);
+ CHECK_REG(PT_RESULT, result);
+ #undef CHECK_REG
+
+ BUILD_BUG_ON(PT_REGS_COUNT != sizeof(struct user_pt_regs) / sizeof(unsigned long));
+
+ /*
+ * PT_DSCR isn't a real reg, but it's important that it doesn't overlap the
+ * real registers.
+ */
+ BUILD_BUG_ON(PT_DSCR < sizeof(struct user_pt_regs) / sizeof(unsigned long));
+
+ // ptrace_get/put_fpr() rely on PPC32 and VSX being incompatible
+ BUILD_BUG_ON(IS_ENABLED(CONFIG_PPC32) && IS_ENABLED(CONFIG_VSX));
+}
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