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[198.145.64.163]) by smtp.gmail.com with ESMTPSA id i63sm6601330pje.34.2020.06.19.20.30.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Jun 2020 20:30:26 -0700 (PDT) From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Kees Cook , Linus Torvalds , Miguel Ojeda , Alexander Potapenko , Joe Perches , Andy Whitcroft , x86@kernel.org, drbd-dev@lists.linbit.com, linux-block@vger.kernel.org, b43-dev@lists.infradead.org, netdev@vger.kernel.org, linux-doc@vger.kernel.org, linux-wireless@vger.kernel.org, linux-ide@vger.kernel.org, linux-clk@vger.kernel.org, linux-spi@vger.kernel.org, linux-mm@kvack.org, clang-built-linux@googlegroups.com Subject: [PATCH v2 14/16] checkpatch: Remove awareness of uninitialized_var() macro Date: Fri, 19 Jun 2020 20:30:04 -0700 Message-Id: <20200620033007.1444705-14-keescook@chromium.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200620033007.1444705-1-keescook@chromium.org> References: <20200620033007.1444705-1-keescook@chromium.org> MIME-Version: 1.0 X-Rspamd-Queue-Id: BFFE2180C07AB X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000002, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], partially revert commit 16b7f3c89907 ("checkpatch: avoid warning about uninitialized_var()") and remove all remaining mentions of uninitialized_var(). [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Signed-off-by: Kees Cook --- scripts/checkpatch.pl | 16 +++++----------- 1 file changed, 5 insertions(+), 11 deletions(-) diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl index 4c820607540b..60b737e222fe 100755 --- a/scripts/checkpatch.pl +++ b/scripts/checkpatch.pl @@ -840,7 +840,6 @@ our $FuncArg = qr{$Typecast{0,1}($LvalOrFunc|$Constant|$String)}; our $declaration_macros = qr{(?x: (?:$Storage\s+)?(?:[A-Z_][A-Z0-9]*_){0,2}(?:DEFINE|DECLARE)(?:_[A-Z0-9]+){1,6}\s*\(| (?:$Storage\s+)?[HLP]?LIST_HEAD\s*\(| - (?:$Storage\s+)?${Type}\s+uninitialized_var\s*\(| (?:SKCIPHER_REQUEST|SHASH_DESC|AHASH_REQUEST)_ON_STACK\s*\( )}; @@ -6330,8 +6329,7 @@ sub process { if (defined $cond) { substr($s, 0, length($cond), ''); } - if ($s =~ /^\s*;/ && - $function_name ne 'uninitialized_var') + if ($s =~ /^\s*;/) { WARN("AVOID_EXTERNS", "externs should be avoided in .c files\n" . $herecurr); @@ -6350,17 +6348,13 @@ sub process { } # check for function declarations that have arguments without identifier names -# while avoiding uninitialized_var(x) if (defined $stat && - $stat =~ /^.\s*(?:extern\s+)?$Type\s*(?:($Ident)|\(\s*\*\s*$Ident\s*\))\s*\(\s*([^{]+)\s*\)\s*;/s && - (!defined($1) || - (defined($1) && $1 ne "uninitialized_var")) && - $2 ne "void") { - my $args = trim($2); + $stat =~ /^.\s*(?:extern\s+)?$Type\s*(?:$Ident|\(\s*\*\s*$Ident\s*\))\s*\(\s*([^{]+)\s*\)\s*;/s && + $1 ne "void") { + my $args = trim($1); while ($args =~ m/\s*($Type\s*(?:$Ident|\(\s*\*\s*$Ident?\s*\)\s*$balanced_parens)?)/g) { my $arg = trim($1); - if ($arg =~ /^$Type$/ && - $arg !~ /enum\s+$Ident$/) { + if ($arg =~ /^$Type$/ && $arg !~ /enum\s+$Ident$/) { WARN("FUNCTION_ARGUMENTS", "function definition argument '$arg' should also have an identifier name\n" . $herecurr); }