ash: add comment about bash's ENOEXEC handling. No code changes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 14472cb61..d02b74a4c 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -7435,6 +7435,12 @@ tryexec(IF_FEATURE_SH_STANDALONE(int applet_no,) char *cmd, char **argv, char **
                  *
                  * That is, do not use $SHELL, user's shell, or /bin/sh;
                  * just call ourselves.
+                 *
+                 * Note that bash reads ~80 chars of the file, and if it sees
+                 * a zero byte before it sees newline, it doesn't try to
+                 * interpret it, but fails with "cannot execute binary file"
+                 * message. For one, it prevents atempts to interpret
+                 * foreign ELF binaries as shell scripts.
                  */
                 char **ap;
                 char **new;