scripts: checkpatch.pl: add 2 new checks on memset calls

This patch adds 2 new checks on memset calls in the file checkpatch.pl as follows:

replace memset by eth_zero_addr if the second argument is an address of zeros (0x00). eth_zero_addr is a wrapper function for memset that takes an address array to set as zero. The size address has to be ETH_ALEN.

scripts/checkpatch.pl +10 -0

+					 "Prefer eth_zero_addr() over memset() if the second address is 0x00\n" . $herecurr) &&
+				    $fix) {
+
+					$fixed[$fixlinenr] =~ s/\bmemset\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\,\s*ETH_ALEN\s*\)/eth_zero_addr($ms_addr)/;
+				} elsif ($ms_val =~ /^0xff/i && WARN("PREFER_ETH_BROADCAST_ADDR",
+					 "Prefer eth_broadcast_addr() over memset() if the second address is 0xff\n" . $herecurr) &&
+				    $fix) {
+
+					$fixed[$fixlinenr] =~ s/\bmemset\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\,\s*ETH_ALEN\s*\)/eth_broadcast_addr($ms_addr)/;
+				}
 			}
 		}
 

Quoted 7 lines · Aya Mahfouz

This patch adds 2 new checks on memset calls in the file checkpatch.pl as follows:

replace memset by eth_zero_addr if the second argument is an address of zeros (0x00). eth_zero_addr is a wrapper function for memset that takes an address array to set as zero. The size address has to be ETH_ALEN.

[]

scripts/checkpatch.pl

Quoted 1 line

scripts/checkpatch.pl +0 -0

[]

scripts/checkpatch.pl sub process { · line 4909

Quoted 12 lines

scripts/checkpatch.pl +4 -2

@@ -4901,10 +4901,22 @@ sub process {
 
 			if ($ms_size =~ /^(0x|)0$/i) {
 				ERROR("MEMSET",
-				      "memset to 0's uses 0 as the 2nd argument, not the 3rd\n" . "$here\n$stat\n");
+				      "memset to 0's uses 0 as the 2nd argument, not the 3rd\n" . "$here\n$line\n");
 			} elsif ($ms_size =~ /^(0x|)1$/i) {
 				WARN("MEMSET",
-				     "single byte memset is suspicious. Swapped 2nd/3rd argument?\n" . "$here\n$stat\n");
+				     "single byte memset is suspicious. Swapped 2nd/3rd argument?\n" . "$here\n$line\n");
+			} elsif ($ms_size =~ /^ETH_ALEN/i) {
+				if ($ms_val =~ /^0x00/i && WARN("PREFER_ETH_ZERO_ADDR",

This isn't right. Look again at what I suggested.

This would match 0x00ff and wouldn't match 0

scripts/checkpatch.pl sub process { · line 4922

Quoted 13 lines

scripts/checkpatch.pl +10 -0

+					 "Prefer eth_zero_addr() over memset() if the second address is 0x00\n" . $herecurr) &&
+				    $fix) {
+
+					$fixed[$fixlinenr] =~ s/\bmemset\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\,\s*ETH_ALEN\s*\)/eth_zero_addr($ms_addr)/;
+				} elsif ($ms_val =~ /^0xff/i && WARN("PREFER_ETH_BROADCAST_ADDR",
+					 "Prefer eth_broadcast_addr() over memset() if the second address is 0xff\n" . $herecurr) &&
+				    $fix) {
+
+					$fixed[$fixlinenr] =~ s/\bmemset\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\,\s*ETH_ALEN\s*\)/eth_broadcast_addr($ms_addr)/;
+				}
 			}
 		}
 

Quoted 3 lines · Joe Perches

Quoted 2 lines · Aya Mahfouz

This patch adds 2 new checks on memset calls in the file checkpatch.pl as follows:

ok, I didn't see your suggestion, sorry.

Can you look at the following
modification before sending the third patch? I don't use $stat because I get false positives with it.

Quoted 4 lines · Aya Mahfouz

Quoted 3 lines · Joe Perches

Quoted 2 lines · Aya Mahfouz

This patch adds 2 new checks on memset calls in the file checkpatch.pl as follows:

[]

Quoted 1 line

ok, I didn't see your suggestion, sorry.

No worries.

Quoted 3 lines

Can you look at the following
modification before sending the third patch? I don't use $stat because I get false positives with it.

Please describe the false positives.

Quoted 8 lines · Joe Perches

Quoted 4 lines · Aya Mahfouz

Quoted 3 lines · Joe Perches

Quoted 2 lines · Aya Mahfouz

This patch adds 2 new checks on memset calls in the file checkpatch.pl as follows:

[]

Quoted 1 line

ok, I didn't see your suggestion, sorry.

Quoted 9 lines

No worries.

Quoted 3 lines

Can you look at the following
modification before sending the third patch? I don't use $stat because I get false positives with it.

Please describe the false positives.

ok, here are the relevant warnings issued by checkpatch.pl when using $stat for the file drivers/staging/rtl8188eu/os_dep/ioctl_linux.c. The only correct results are lines 95, 830, 1031, 1040, 1908.

WARNING: Prefer eth_zero_addr() over memset() if the second address is 0x00 #95: FILE: drivers/staging/rtl8188eu/os_dep/ioctl_linux.c:95:

(quoted diff) +1 -0

+	memset(wrqu.ap_addr.sa_data, 0, ETH_ALEN);

WARNING: Prefer eth_zero_addr() over memset() if the second address is 0x00 #775: FILE: drivers/staging/rtl8188eu/os_dep/ioctl_linux.c:775:
+}

Quoted 28 lines · Aya Mahfouz

Quoted 8 lines · Joe Perches

Quoted 4 lines · Aya Mahfouz

Quoted 3 lines · Joe Perches

Quoted 2 lines · Aya Mahfouz

This patch adds 2 new checks on memset calls in the file checkpatch.pl as follows:

[]

Quoted 1 line

ok, I didn't see your suggestion, sorry.

Quoted 9 lines

No worries.

Quoted 3 lines

Can you look at the following
modification before sending the third patch? I don't use $stat because I get false positives with it.

Please describe the false positives.

ok, here are the relevant warnings issued by checkpatch.pl when using $stat for the file drivers/staging/rtl8188eu/os_dep/ioctl_linux.c. The only correct results are lines 95, 830, 1031, 1040, 1908.

WARNING: Prefer eth_zero_addr() over memset() if the second address is 0x00 #95: FILE: drivers/staging/rtl8188eu/os_dep/ioctl_linux.c:95:

(quoted diff) +1 -0

+	memset(wrqu.ap_addr.sa_data, 0, ETH_ALEN);

Quoted 3 lines

WARNING: Prefer eth_zero_addr() over memset() if the second address is 0x00 #775: FILE: drivers/staging/rtl8188eu/os_dep/ioctl_linux.c:775:
+}

[]

Try this:

---
 scripts/checkpatch.pl | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

scripts/checkpatch.pl +10 -4

index d124359..9127c65 100755
@@ -4890,10 +4890,11 @@ sub process {
 			}
 		}
 
-# Check for misused memsets
+# Check for misused memsets then check for memset(foo, 0x00|0xff, ETH_ALEN)
+# calls that could be eth_zero_addr(foo)|eth_broadcast_addr(foo)
 		if ($^V && $^V ge 5.10.0 &&
 		    defined $stat &&
-		    $stat =~ /^\+(?:.*?)\bmemset\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\,\s*$FuncArg\s*\)/s) {
+		    $stat =~ /^\+(?:\s*$Ident\s*=)?\s*memset\s*\(\s*$FuncArg\s*,\s*$FuncArg\s*\,\s*$FuncArg\s*\)/s) {
 
 			my $ms_addr = $2;
 			my $ms_val = $7;

@@ -4901,10 +4902,22 @@ sub process {
 
 			if ($ms_size =~ /^(0x|)0$/i) {
 				ERROR("MEMSET",
-				      "memset to 0's uses 0 as the 2nd argument, not the 3rd\n" . "$here\n$stat\n");
+				      "memset to 0's uses 0 as the 2nd argument, not the 3rd\n" . "$here\n$line\n");
 			} elsif ($ms_size =~ /^(0x|)1$/i) {
 				WARN("MEMSET",
-				     "single byte memset is suspicious. Swapped 2nd/3rd argument?\n" . "$here\n$stat\n");
+				     "single byte memset is suspicious. Swapped 2nd/3rd argument?\n" . "$here\n$line\n");
+			} elsif ($ms_val =~ /^(?:0x)?0+$/i &&
+				 $ms_size =~ /^ETH_ALEN$/ &&
+				 WARN("PREFER_ETH_ADDR",
+				     "Prefer eth_zero_addr() over memset() if the second address is 0\n" . $herecurr) &&
+				 $fix) {

What is the next step?

Quoted 1 line · Aya Mahfouz

What is the next step?

Ideally, you understanding why the suggested patch is an improvement over the patch you proposed.

Beyond that, submit a patch. Then submit more...

cheers, Joe

Quoted 5 lines · Joe Perches

Quoted 1 line · Aya Mahfouz

What is the next step?

Ideally, you understanding why the suggested patch is an improvement over the patch you proposed. Beyond that, submit a patch. Then submit more...

This is just a note that I did not forget about the patch.

I understand how it works now.

I'm just finalizing some final steps with Julia which might take some time.

Thanks for all your help,