kernel: ltq-vectoring: add patch fixing compilation warning

Add patch fixing compilation warning related to stack limit.
Fix compilation warning:
/builder/shared-workdir/build/build_dir/target-mips_24kc_musl/linux-lantiq_xrx200/ltq-vectoring-2019-05-20-4fa7ac30/src/vectoring/ifxmips_vectoring.c: In function 'proc_write_dbg':
/builder/shared-workdir/build/build_dir/target-mips_24kc_musl/linux-lantiq_xrx200/ltq-vectoring-2019-05-20-4fa7ac30/src/vectoring/ifxmips_vectoring.c:369:1: error: the frame size of 2088 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]
  369 | }
      | ^
cc1: all warnings being treated as errors

Signed-off-by: Christian Marangi <[email protected]>

package/kernel/lantiq/ltq-vectoring/patches/300-fix-compilation-warning-stack-limit.patch

@@ -0,0 +1,69 @@
+--- a/src/vectoring/ifxmips_vectoring.c
++++ b/src/vectoring/ifxmips_vectoring.c
+@@ -298,7 +298,7 @@ static int proc_write_dbg(struct file *file, const char __user *buf, size_t coun
+         DBG_ENABLE_MASK_ALL
+     };
+ 
+-    char str[2048];
++    char *str;
+     char *p;
+ 
+     int len, rlen;
+@@ -306,6 +306,10 @@ static int proc_write_dbg(struct file *file, const char __user *buf, size_t coun
+     int f_enable = 0;
+     int i;
+ 
++    str = kcalloc(2048, sizeof(*str), GFP_KERNEL);
++    if (!str)
++        return -ENOMEM;
++
+     len = count < sizeof(str) ? count : sizeof(str) - 1;
+     rlen = len - copy_from_user(str, buf, len);
+     while ( rlen && str[rlen - 1] <= ' ' )
+@@ -365,6 +369,8 @@ static int proc_write_dbg(struct file *file, const char __user *buf, size_t coun
+         }
+     }
+ 
++    kfree(str);
++
+     return count;
+ }
+ 
+--- a/src/vectoring/ifxmips_vectoring_test.c
++++ b/src/vectoring/ifxmips_vectoring_test.c
+@@ -3,6 +3,7 @@
+ #include <linux/module.h>
+ #include <linux/proc_fs.h>
+ #include <linux/seq_file.h>
++#include <linux/slab.h>
+ 
+ #include "ifxmips_vectoring_stub.h"
+ 
+@@ -46,13 +47,17 @@ static int proc_write_vectoring(struct file *file, const char __user *buf, size_
+ {
+     char *p;
+     int len;
+-    char local_buf[1024];
++    char *local_buf;
+ 
+     unsigned long pkt_len;
+     int ret;
+     unsigned long sys_flag;
+     unsigned long start, end;
+ 
++    local_buf = kcalloc(1024, sizeof(*local_buf), GFP_KERNEL);
++    if (!local_buf)
++        return -ENOMEM;
++
+     len = sizeof(local_buf) < count ? sizeof(local_buf) - 1 : count;
+     len = len - copy_from_user(local_buf, buf, len);
+     local_buf[len] = 0;
+@@ -81,6 +86,8 @@ static int proc_write_vectoring(struct file *file, const char __user *buf, size_
+     else
+         printk("echo send <size> > /proc/driver/vectoring_test\n");
+ 
++    kfree(local_buf);
++
+     return count;
+ }
+