X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?p=kvmfornfv.git;a=blobdiff_plain;f=kernel%2Farch%2Farm64%2Fkernel%2Fptrace.c;h=55909b2208cc08ce43e415f13dbc5e60836b90b8;hp=ff7f13239515676262864f3c9d1a7a938c7e63d3;hb=52f993b8e89487ec9ee15a7fb4979e0f09a45b27;hpb=c189ccac5702322ed843fe17057035b7222a59b6

diff --git a/kernel/arch/arm64/kernel/ptrace.c b/kernel/arch/arm64/kernel/ptrace.c
index ff7f13239..55909b220 100644
--- a/kernel/arch/arm64/kernel/ptrace.c
+++ b/kernel/arch/arm64/kernel/ptrace.c
@@ -39,6 +39,7 @@
 #include <linux/elf.h>
 
 #include <asm/compat.h>
+#include <asm/cpufeature.h>
 #include <asm/debug-monitors.h>
 #include <asm/pgtable.h>
 #include <asm/syscall.h>
@@ -449,6 +450,8 @@ static int hw_break_set(struct task_struct *target,
 	/* (address, ctrl) registers */
 	limit = regset->n * regset->size;
 	while (count && offset < limit) {
+		if (count < PTRACE_HBP_ADDR_SZ)
+			return -EINVAL;
 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &addr,
 					 offset, offset + PTRACE_HBP_ADDR_SZ);
 		if (ret)
@@ -458,6 +461,8 @@ static int hw_break_set(struct task_struct *target,
 			return ret;
 		offset += PTRACE_HBP_ADDR_SZ;
 
+		if (!count)
+			break;
 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &ctrl,
 					 offset, offset + PTRACE_HBP_CTRL_SZ);
 		if (ret)
@@ -494,13 +499,13 @@ static int gpr_set(struct task_struct *target, const struct user_regset *regset,
 		   const void *kbuf, const void __user *ubuf)
 {
 	int ret;
-	struct user_pt_regs newregs;
+	struct user_pt_regs newregs = task_pt_regs(target)->user_regs;
 
 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newregs, 0, -1);
 	if (ret)
 		return ret;
 
-	if (!valid_user_regs(&newregs))
+	if (!valid_user_regs(&newregs, target))
 		return -EINVAL;
 
 	task_pt_regs(target)->user_regs = newregs;
@@ -524,7 +529,8 @@ static int fpr_set(struct task_struct *target, const struct user_regset *regset,
 		   const void *kbuf, const void __user *ubuf)
 {
 	int ret;
-	struct user_fpsimd_state newstate;
+	struct user_fpsimd_state newstate =
+		target->thread.fpsimd_state.user_fpsimd;
 
 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &newstate, 0, -1);
 	if (ret)
@@ -548,7 +554,7 @@ static int tls_set(struct task_struct *target, const struct user_regset *regset,
 		   const void *kbuf, const void __user *ubuf)
 {
 	int ret;
-	unsigned long tls;
+	unsigned long tls = target->thread.tp_value;
 
 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 	if (ret)
@@ -574,7 +580,8 @@ static int system_call_set(struct task_struct *target,
 			   unsigned int pos, unsigned int count,
 			   const void *kbuf, const void __user *ubuf)
 {
-	int syscallno, ret;
+	int syscallno = task_pt_regs(target)->syscallno;
+	int ret;
 
 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &syscallno, 0, -1);
 	if (ret)
@@ -770,7 +777,7 @@ static int compat_gpr_set(struct task_struct *target,
 
 	}
 
-	if (valid_user_regs(&newregs.user_regs))
+	if (valid_user_regs(&newregs.user_regs, target))
 		*task_pt_regs(target) = newregs;
 	else
 		ret = -EINVAL;
@@ -846,7 +853,7 @@ static int compat_tls_set(struct task_struct *target,
 			  const void __user *ubuf)
 {
 	int ret;
-	compat_ulong_t tls;
+	compat_ulong_t tls = target->thread.tp_value;
 
 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &tls, 0, -1);
 	if (ret)
@@ -1272,3 +1279,79 @@ asmlinkage void syscall_trace_exit(struct pt_regs *regs)
 	if (test_thread_flag(TIF_SYSCALL_TRACE))
 		tracehook_report_syscall(regs, PTRACE_SYSCALL_EXIT);
 }
+
+/*
+ * Bits which are always architecturally RES0 per ARM DDI 0487A.h
+ * Userspace cannot use these until they have an architectural meaning.
+ * We also reserve IL for the kernel; SS is handled dynamically.
+ */
+#define SPSR_EL1_AARCH64_RES0_BITS \
+	(GENMASK_ULL(63,32) | GENMASK_ULL(27, 22) | GENMASK_ULL(20, 10) | \
+	 GENMASK_ULL(5, 5))
+#define SPSR_EL1_AARCH32_RES0_BITS \
+	(GENMASK_ULL(63,32) | GENMASK_ULL(24, 22) | GENMASK_ULL(20,20))
+
+static int valid_compat_regs(struct user_pt_regs *regs)
+{
+	regs->pstate &= ~SPSR_EL1_AARCH32_RES0_BITS;
+
+	if (!system_supports_mixed_endian_el0()) {
+		if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN))
+			regs->pstate |= COMPAT_PSR_E_BIT;
+		else
+			regs->pstate &= ~COMPAT_PSR_E_BIT;
+	}
+
+	if (user_mode(regs) && (regs->pstate & PSR_MODE32_BIT) &&
+	    (regs->pstate & COMPAT_PSR_A_BIT) == 0 &&
+	    (regs->pstate & COMPAT_PSR_I_BIT) == 0 &&
+	    (regs->pstate & COMPAT_PSR_F_BIT) == 0) {
+		return 1;
+	}
+
+	/*
+	 * Force PSR to a valid 32-bit EL0t, preserving the same bits as
+	 * arch/arm.
+	 */
+	regs->pstate &= COMPAT_PSR_N_BIT | COMPAT_PSR_Z_BIT |
+			COMPAT_PSR_C_BIT | COMPAT_PSR_V_BIT |
+			COMPAT_PSR_Q_BIT | COMPAT_PSR_IT_MASK |
+			COMPAT_PSR_GE_MASK | COMPAT_PSR_E_BIT |
+			COMPAT_PSR_T_BIT;
+	regs->pstate |= PSR_MODE32_BIT;
+
+	return 0;
+}
+
+static int valid_native_regs(struct user_pt_regs *regs)
+{
+	regs->pstate &= ~SPSR_EL1_AARCH64_RES0_BITS;
+
+	if (user_mode(regs) && !(regs->pstate & PSR_MODE32_BIT) &&
+	    (regs->pstate & PSR_D_BIT) == 0 &&
+	    (regs->pstate & PSR_A_BIT) == 0 &&
+	    (regs->pstate & PSR_I_BIT) == 0 &&
+	    (regs->pstate & PSR_F_BIT) == 0) {
+		return 1;
+	}
+
+	/* Force PSR to a valid 64-bit EL0t */
+	regs->pstate &= PSR_N_BIT | PSR_Z_BIT | PSR_C_BIT | PSR_V_BIT;
+
+	return 0;
+}
+
+/*
+ * Are the current registers suitable for user mode? (used to maintain
+ * security in signal handlers)
+ */
+int valid_user_regs(struct user_pt_regs *regs, struct task_struct *task)
+{
+	if (!test_tsk_thread_flag(task, TIF_SINGLESTEP))
+		regs->pstate &= ~DBG_SPSR_SS;
+
+	if (is_compat_thread(task_thread_info(task)))
+		return valid_compat_regs(regs);
+	else
+		return valid_native_regs(regs);
+}