From 5b4ad89f381e2c864395af2b762d75151c03fdb3 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Tue, 8 Mar 2016 11:34:01 -0500 Subject: [PATCH] Fix: filter interpreter with userspace strings The filter interpreter is populating the "str" register field, but the string comparison functions expect to use the "user_str" register field whenever it deals with a userspace string ("user" flag set to 1). Since we are using __copy_from_user_inatomic(), this is typically bailing out on anything that requires to read the string (except the '*' wildcard). Fixes #943 Signed-off-by: Mathieu Desnoyers --- lttng-filter-interpreter.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lttng-filter-interpreter.c b/lttng-filter-interpreter.c index c288cc02..713a9d7d 100644 --- a/lttng-filter-interpreter.c +++ b/lttng-filter-interpreter.c @@ -818,7 +818,7 @@ uint64_t lttng_filter_interpret_bytecode(void *filter_data, dbg_printk("load field ref offset %u type user string\n", ref->offset); estack_push(stack, top, ax, bx); - estack_ax(stack, top)->u.s.str = + estack_ax(stack, top)->u.s.user_str = *(const char * const *) &filter_stack_data[ref->offset]; if (unlikely(!estack_ax(stack, top)->u.s.str)) { dbg_printk("Filter warning: loading a NULL string.\n"); @@ -843,7 +843,7 @@ uint64_t lttng_filter_interpret_bytecode(void *filter_data, estack_push(stack, top, ax, bx); estack_ax(stack, top)->u.s.seq_len = *(unsigned long *) &filter_stack_data[ref->offset]; - estack_ax(stack, top)->u.s.str = + estack_ax(stack, top)->u.s.user_str = *(const char **) (&filter_stack_data[ref->offset + sizeof(unsigned long)]); if (unlikely(!estack_ax(stack, top)->u.s.str)) { -- 2.34.1