When a debugger faults in a page for a debugee, we do not need to update

the mmu cache/tlbs, since the debugger will use a kernel address to access
the page, and not the user address. This should fix the strace warning
messages that Ralf and Ulf have seen. Fix should be backported into MIPS.

2 files changed, 12 insertions, 0 deletions

diff --git a/arch/mips64/mm/andes.c b/arch/mips64/mm/andes.c
index bcff62ad9..3dfabd169 100644
--- a/arch/mips64/mm/andes.c
+++ b/arch/mips64/mm/andes.c
@@ -376,6 +376,12 @@ static void andes_update_mmu_cache(struct vm_area_struct * vma,
 	pte_t *ptep;
 	int idx, pid;
 
+	/*
+	 * Handle debugger faulting in for debugee.
+	 */
+	if (current->active_mm != vma->vm_mm)
+		return;
+
 	__save_and_cli(flags);
 	pid = get_entryhi() & 0xff;
 
diff --git a/arch/mips64/mm/r4xx0.c b/arch/mips64/mm/r4xx0.c
index 5fa267d6d..1b2fb35bf 100644
--- a/arch/mips64/mm/r4xx0.c
+++ b/arch/mips64/mm/r4xx0.c
@@ -2170,6 +2170,12 @@ static void r4k_update_mmu_cache(struct vm_area_struct * vma,
 	pte_t *ptep;
 	int idx, pid;
 
+	/*
+	 * Handle debugger faulting in for debugee.
+	 */
+	if (current->active_mm != vma->vm_mm)
+		return;
+
 	__save_and_cli(flags);
 	pid = (get_entryhi() & 0xff);