perf expr: Fix missing check for return value of hashmap__new()

The hashmap__new() function may return ERR_PTR(-ENOMEM) when malloc()
fails, add IS_ERR() checking for ctx->ids.

Signed-off-by: Miaoqian Lin <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lore.kernel.org/lkml/[email protected]
[ s/kfree()/free()/ and add missing linux/err.h include ]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

Author: Yuuoniy

tools/perf/util/expr.c

@@ -12,6 +12,7 @@
 #include "expr-bison.h"
 #include "expr-flex.h"
 #include "smt.h"
+#include <linux/err.h>
 #include <linux/kernel.h>
 #include <linux/zalloc.h>
 #include <ctype.h>
@@ -299,6 +300,10 @@ struct expr_parse_ctx *expr__ctx_new(void)
 		return NULL;
 
 	ctx->ids = hashmap__new(key_hash, key_equal, NULL);
+	if (IS_ERR(ctx->ids)) {
+		free(ctx);
+		return NULL;
+	}
 	ctx->runtime = 0;
 
 	return ctx;