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From:   Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>,
        linux-kernel@vger.kernel.org
Cc:     Dan Carpenter <error27@gmail.com>, Takashi Iwai <tiwai@suse.de>,
        Kees Cook <keescook@chromium.org>,
        "Luis R. Rodriguez" <mcgrof@ruslug.rutgers.edu>,
        Scott Branden <sbranden@broadcom.com>,
        Hans de Goede <hdegoede@redhat.com>,
        Brian Norris <briannorris@chromium.org>
Subject: [PATCH v2 1/1] test_firmware: return ENOMEM instead of ENOSPC on failed memory allocation
Date:   Tue,  6 Jun 2023 09:08:10 +0200
Message-Id: <20230606070808.9300-1-mirsad.todorovac@alu.unizg.hr>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

In a couple of situations like

	name = kstrndup(buf, count, GFP_KERNEL);
	if (!name)
		return -ENOSPC;

the error is not actually "No space left on device", but "Out of memory".

It is semantically correct to return -ENOMEM in all failed kstrndup()
and kzalloc() cases in this driver, as it is not a problem with disk
space, but with kernel memory allocator failing allocation.

The semantically correct should be:

        name = kstrndup(buf, count, GFP_KERNEL);
        if (!name)
                return -ENOMEM;

Cc: Dan Carpenter <error27@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Luis R. Rodriguez" <mcgrof@ruslug.rutgers.edu>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Brian Norris <briannorris@chromium.org>
Fixes: c92316bf8e948 ("test_firmware: add batched firmware tests")
Fixes: 0a8adf584759c ("test: add firmware_class loader test")
Fixes: 548193cba2a7d ("test_firmware: add support for firmware_request_platform")
Fixes: eb910947c82f9 ("test: firmware_class: add asynchronous request trigger")
Fixes: 061132d2b9c95 ("test_firmware: add test custom fallback trigger")
Fixes: 7feebfa487b92 ("test_firmware: add support for request_firmware_into_buf")
Signed-off-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
---
 v1 -> v2:
    - minor clarifications in description and subject line
    - added Fixes: lines
    - added Cc: to authors of the fixed commits
    - removed Cc: stable as suggested

 lib/test_firmware.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/lib/test_firmware.c b/lib/test_firmware.c
index 1d7d480b8eeb..add4699fc6cd 100644
--- a/lib/test_firmware.c
+++ b/lib/test_firmware.c
@@ -214,7 +214,7 @@ static int __kstrncpy(char **dst, const char *name, size_t count, gfp_t gfp)
 {
 	*dst = kstrndup(name, count, gfp);
 	if (!*dst)
-		return -ENOSPC;
+		return -ENOMEM;
 	return count;
 }
 
@@ -671,7 +671,7 @@ static ssize_t trigger_request_store(struct device *dev,
 
 	name = kstrndup(buf, count, GFP_KERNEL);
 	if (!name)
-		return -ENOSPC;
+		return -ENOMEM;
 
 	pr_info("loading '%s'\n", name);
 
@@ -719,7 +719,7 @@ static ssize_t trigger_request_platform_store(struct device *dev,
 
 	name = kstrndup(buf, count, GFP_KERNEL);
 	if (!name)
-		return -ENOSPC;
+		return -ENOMEM;
 
 	pr_info("inserting test platform fw '%s'\n", name);
 	efi_embedded_fw.name = name;
@@ -772,7 +772,7 @@ static ssize_t trigger_async_request_store(struct device *dev,
 
 	name = kstrndup(buf, count, GFP_KERNEL);
 	if (!name)
-		return -ENOSPC;
+		return -ENOMEM;
 
 	pr_info("loading '%s'\n", name);
 
@@ -817,7 +817,7 @@ static ssize_t trigger_custom_fallback_store(struct device *dev,
 
 	name = kstrndup(buf, count, GFP_KERNEL);
 	if (!name)
-		return -ENOSPC;
+		return -ENOMEM;
 
 	pr_info("loading '%s' using custom fallback mechanism\n", name);
 
@@ -868,7 +868,7 @@ static int test_fw_run_batch_request(void *data)
 
 		test_buf = kzalloc(TEST_FIRMWARE_BUF_SIZE, GFP_KERNEL);
 		if (!test_buf)
-			return -ENOSPC;
+			return -ENOMEM;
 
 		if (test_fw_config->partial)
 			req->rc = request_partial_firmware_into_buf
-- 
2.34.1