Adding upstream version 6.1.76.upstream/6.1.76

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

1 files changed, 158 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/hw_breakpoint_constraints.c b/arch/powerpc/kernel/hw_breakpoint_constraints.c
new file mode 100644
index 000000000..9e51801c4
--- /dev/null
+++ b/arch/powerpc/kernel/hw_breakpoint_constraints.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0+
+#include <linux/kernel.h>
+#include <linux/uaccess.h>
+#include <linux/sched.h>
+#include <asm/hw_breakpoint.h>
+#include <asm/sstep.h>
+#include <asm/cache.h>
+
+static bool dar_in_user_range(unsigned long dar, struct arch_hw_breakpoint *info)
+{
+	return ((info->address <= dar) && (dar - info->address < info->len));
+}
+
+static bool ea_user_range_overlaps(unsigned long ea, int size,
+				   struct arch_hw_breakpoint *info)
+{
+	return ((ea < info->address + info->len) &&
+		(ea + size > info->address));
+}
+
+static bool dar_in_hw_range(unsigned long dar, struct arch_hw_breakpoint *info)
+{
+	unsigned long hw_start_addr, hw_end_addr;
+
+	hw_start_addr = ALIGN_DOWN(info->address, HW_BREAKPOINT_SIZE);
+	hw_end_addr = ALIGN(info->address + info->len, HW_BREAKPOINT_SIZE);
+
+	return ((hw_start_addr <= dar) && (hw_end_addr > dar));
+}
+
+static bool ea_hw_range_overlaps(unsigned long ea, int size,
+				 struct arch_hw_breakpoint *info)
+{
+	unsigned long hw_start_addr, hw_end_addr;
+	unsigned long align_size = HW_BREAKPOINT_SIZE;
+
+	/*
+	 * On p10 predecessors, quadword is handle differently then
+	 * other instructions.
+	 */
+	if (!cpu_has_feature(CPU_FTR_ARCH_31) && size == 16)
+		align_size = HW_BREAKPOINT_SIZE_QUADWORD;
+
+	hw_start_addr = ALIGN_DOWN(info->address, align_size);
+	hw_end_addr = ALIGN(info->address + info->len, align_size);
+
+	return ((ea < hw_end_addr) && (ea + size > hw_start_addr));
+}
+
+/*
+ * If hw has multiple DAWR registers, we also need to check all
+ * dawrx constraint bits to confirm this is _really_ a valid event.
+ * If type is UNKNOWN, but privilege level matches, consider it as
+ * a positive match.
+ */
+static bool check_dawrx_constraints(struct pt_regs *regs, int type,
+				    struct arch_hw_breakpoint *info)
+{
+	if (OP_IS_LOAD(type) && !(info->type & HW_BRK_TYPE_READ))
+		return false;
+
+	/*
+	 * The Cache Management instructions other than dcbz never
+	 * cause a match. i.e. if type is CACHEOP, the instruction
+	 * is dcbz, and dcbz is treated as Store.
+	 */
+	if ((OP_IS_STORE(type) || type == CACHEOP) && !(info->type & HW_BRK_TYPE_WRITE))
+		return false;
+
+	if (is_kernel_addr(regs->nip) && !(info->type & HW_BRK_TYPE_KERNEL))
+		return false;
+
+	if (user_mode(regs) && !(info->type & HW_BRK_TYPE_USER))
+		return false;
+
+	return true;
+}
+
+/*
+ * Return true if the event is valid wrt dawr configuration,
+ * including extraneous exception. Otherwise return false.
+ */
+bool wp_check_constraints(struct pt_regs *regs, ppc_inst_t instr,
+			  unsigned long ea, int type, int size,
+			  struct arch_hw_breakpoint *info)
+{
+	bool in_user_range = dar_in_user_range(regs->dar, info);
+	bool dawrx_constraints;
+
+	/*
+	 * 8xx supports only one breakpoint and thus we can
+	 * unconditionally return true.
+	 */
+	if (IS_ENABLED(CONFIG_PPC_8xx)) {
+		if (!in_user_range)
+			info->type |= HW_BRK_TYPE_EXTRANEOUS_IRQ;
+		return true;
+	}
+
+	if (unlikely(ppc_inst_equal(instr, ppc_inst(0)))) {
+		if (cpu_has_feature(CPU_FTR_ARCH_31) &&
+		    !dar_in_hw_range(regs->dar, info))
+			return false;
+
+		return true;
+	}
+
+	dawrx_constraints = check_dawrx_constraints(regs, type, info);
+
+	if (type == UNKNOWN) {
+		if (cpu_has_feature(CPU_FTR_ARCH_31) &&
+		    !dar_in_hw_range(regs->dar, info))
+			return false;
+
+		return dawrx_constraints;
+	}
+
+	if (ea_user_range_overlaps(ea, size, info))
+		return dawrx_constraints;
+
+	if (ea_hw_range_overlaps(ea, size, info)) {
+		if (dawrx_constraints) {
+			info->type |= HW_BRK_TYPE_EXTRANEOUS_IRQ;
+			return true;
+		}
+	}
+	return false;
+}
+
+void wp_get_instr_detail(struct pt_regs *regs, ppc_inst_t *instr,
+			 int *type, int *size, unsigned long *ea)
+{
+	struct instruction_op op;
+	int err;
+
+	pagefault_disable();
+	err = __get_user_instr(*instr, (void __user *)regs->nip);
+	pagefault_enable();
+
+	if (err)
+		return;
+
+	analyse_instr(&op, regs, *instr);
+	*type = GETTYPE(op.type);
+	*ea = op.ea;
+
+	if (!(regs->msr & MSR_64BIT))
+		*ea &= 0xffffffffUL;
+
+
+	*size = GETSIZE(op.type);
+	if (*type == CACHEOP) {
+		*size = l1_dcache_bytes();
+		*ea &= ~(*size - 1);
+	} else if (*type == LOAD_VMX || *type == STORE_VMX) {
+		*ea &= ~(*size - 1);
+	}
+}