Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 494 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/ptrace/ptrace.c b/arch/powerpc/kernel/ptrace/ptrace.c
new file mode 100644
index 000000000..9ea9ee513
--- /dev/null
+++ b/arch/powerpc/kernel/ptrace/ptrace.c
@@ -0,0 +1,494 @@
+/*
+ *  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).
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License.  See the file README.legal in the main directory of
+ * this archive for more details.
+ */
+
+#include <linux/regset.h>
+#include <linux/tracehook.h>
+#include <linux/audit.h>
+#include <linux/context_tracking.h>
+#include <linux/syscalls.h>
+
+#include <asm/switch_to.h>
+#include <asm/asm-prototypes.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 */
+#ifdef CONFIG_PPC32
+		index = addr >> 2;
+		if ((addr & 3) || (index > PT_FPSCR)
+		    || (child->thread.regs == NULL))
+#else
+		index = addr >> 3;
+		if ((addr & 7) || (index > PT_FPSCR))
+#endif
+			break;
+
+		CHECK_FULL_REGS(child->thread.regs);
+		if (index < PT_FPR0) {
+			ret = ptrace_get_reg(child, (int) index, &tmp);
+			if (ret)
+				break;
+		} else {
+			unsigned int fpidx = index - PT_FPR0;
+
+			flush_fp_to_thread(child);
+			if (fpidx < (PT_FPSCR - PT_FPR0))
+				if (IS_ENABLED(CONFIG_PPC32)) {
+					// On 32-bit the index we are passed refers to 32-bit words
+					tmp = ((u32 *)child->thread.fp_state.fpr)[fpidx];
+				} else {
+					memcpy(&tmp, &child->thread.TS_FPR(fpidx),
+					       sizeof(long));
+				}
+			else
+				tmp = child->thread.fp_state.fpscr;
+		}
+		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 */
+#ifdef CONFIG_PPC32
+		index = addr >> 2;
+		if ((addr & 3) || (index > PT_FPSCR)
+		    || (child->thread.regs == NULL))
+#else
+		index = addr >> 3;
+		if ((addr & 7) || (index > PT_FPSCR))
+#endif
+			break;
+
+		CHECK_FULL_REGS(child->thread.regs);
+		if (index < PT_FPR0) {
+			ret = ptrace_put_reg(child, index, data);
+		} else {
+			unsigned int fpidx = index - PT_FPR0;
+
+			flush_fp_to_thread(child);
+			if (fpidx < (PT_FPSCR - PT_FPR0))
+				if (IS_ENABLED(CONFIG_PPC32)) {
+					// On 32-bit the index we are passed refers to 32-bit words
+					((u32 *)child->thread.fp_state.fpr)[fpidx] = data;
+				} else {
+					memcpy(&child->thread.TS_FPR(fpidx), &data,
+					       sizeof(long));
+				}
+			else
+				child->thread.fp_state.fpscr = data;
+			ret = 0;
+		}
+		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;
+
+	user_exit();
+
+	flags = READ_ONCE(current_thread_info()->flags) &
+		(_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE);
+
+	if (flags) {
+		int rc = tracehook_report_syscall_entry(regs);
+
+		if (unlikely(flags & _TIF_SYSCALL_EMU)) {
+			/*
+			 * A nonzero return code from
+			 * tracehook_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))
+		tracehook_report_syscall_exit(regs, step);
+
+	user_enter();
+}
+
+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, 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, dsisr) !=
+		     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));
+}