From 8485b98f0551f58935f15487cfcc1ec9d53e44ba Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Sun, 10 May 2020 18:38:58 +0000 Subject: [PATCH] scripts/kernel-functions: Suppress RHEL warnings about module_init() / module_exit() git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@8890 d57e44dd-8a1f-0410-8b47-8ef2f437770f --- scripts/kernel-functions | 121 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 117 insertions(+), 4 deletions(-) diff --git a/scripts/kernel-functions b/scripts/kernel-functions index 704761339..8c78ea7d3 100644 --- a/scripts/kernel-functions +++ b/scripts/kernel-functions @@ -127,8 +127,8 @@ function extract_kernel_tree { # Patch a kernel tree where $1 is the kernel version. function patch_kernel { - if [ "$1" = "2.6.29" ] || [ "$1" = "2.6.29.1" ] || [ "$1" = "2.6.29.2" ] || [ "$1" = "2.6.29.3" ] - then + if [ "$1" = "2.6.29" ] || [ "$1" = "2.6.29.1" ] || [ "$1" = "2.6.29.2" ] || + [ "$1" = "2.6.29.3" ]; then patch -f -s -p1 <<'EOF' Make sure that branch profiling does not trigger sparse warnings. See also http://bugzilla.kernel.org/show_bug.cgi?id=12925 @@ -148,8 +148,8 @@ See also http://lkml.org/lkml/2009/4/5/120 #define likely_notrace(x) __builtin_expect(!!(x), 1) EOF fi - if [ "${1#2.6.31}" != "$1" ] - then + + if [ "${1#2.6.31}" != "$1" ]; then patch -f -s -p1 <<'EOF' Checking a 2.6.31.1 kernel configured with allyesconfig/allmodconfig with sparse (make C=2) triggers a sparse warning on code that uses the @@ -203,6 +203,7 @@ Get rid of sparse errors on sk_buff.protocol. #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) EOF fi + if [ "${1#3.13}" != "$1" ]; then if [ "$1" = "3.13" ] || [ "${1#3.13.}" -lt 6 ]; then patch -f -s -p1 <<'EOF' @@ -244,6 +245,7 @@ index 3f2793d..96e45ea 100644 EOF fi fi + if [ "${1#4.15}" != "$1" ]; then patch -f -s -p1 <<'EOF' From ad343a98e74e85aa91d844310e797f96fee6983b Mon Sep 17 00:00:00 2001 @@ -334,6 +336,7 @@ index d6d65537b0d9..6aad8308a0ac 100644 } EOF fi + case "$1" in 2.6.3[6-9]*|3.[0-9]|3.[0-9].*|3.1[01345]|3.1[01345].*|3.1[789]|3.1[789].*|4.[023567]|4.[023567].*) patch -p1 <<'EOF' @@ -399,6 +402,9 @@ index 0ed6ce300543..c324b43712f0 100644 KBUILD_LDFLAGS_MODULE := -T $(srctree)/scripts/module-common.lds EOF ;; + # The patch below does not apply on the CentOS 6 kernel. + 2.6.32-*) + ;; 2.6.3[1-5]*) patch -p1 <<'EOF' diff --git a/Makefile b/Makefile @@ -425,6 +431,113 @@ EOF ;; esac + case "$1" in + 4.18.0-*) # CentOS 8.x + patch -p1 <<'EOF' +From a6e60d84989fa0e91db7f236eda40453b0e44afa Mon Sep 17 00:00:00 2001 +From: Miguel Ojeda +Date: Sat, 19 Jan 2019 20:59:34 +0100 +Subject: [PATCH] include/linux/module.h: copy __init/__exit attrs to + init/cleanup_module + +The upcoming GCC 9 release extends the -Wmissing-attributes warnings +(enabled by -Wall) to C and aliases: it warns when particular function +attributes are missing in the aliases but not in their target. + +In particular, it triggers for all the init/cleanup_module +aliases in the kernel (defined by the module_init/exit macros), +ending up being very noisy. + +These aliases point to the __init/__exit functions of a module, +which are defined as __cold (among other attributes). However, +the aliases themselves do not have the __cold attribute. + +Since the compiler behaves differently when compiling a __cold +function as well as when compiling paths leading to calls +to __cold functions, the warning is trying to point out +the possibly-forgotten attribute in the alias. + +In order to keep the warning enabled, we decided to silence +this case. Ideally, we would mark the aliases directly +as __init/__exit. However, there are currently around 132 modules +in the kernel which are missing __init/__exit in their init/cleanup +functions (either because they are missing, or for other reasons, +e.g. the functions being called from somewhere else); and +a section mismatch is a hard error. + +A conservative alternative was to mark the aliases as __cold only. +However, since we would like to eventually enforce __init/__exit +to be always marked, we chose to use the new __copy function +attribute (introduced by GCC 9 as well to deal with this). +With it, we copy the attributes used by the target functions +into the aliases. This way, functions that were not marked +as __init/__exit won't have their aliases marked either, +and therefore there won't be a section mismatch. + +Note that the warning would go away marking either the extern +declaration, the definition, or both. However, we only mark +the definition of the alias, since we do not want callers +(which only see the declaration) to be compiled as if the function +was __cold (and therefore the paths leading to those calls +would be assumed to be unlikely). + +Link: https://lore.kernel.org/lkml/20190123173707.GA16603@gmail.com/ +Link: https://lore.kernel.org/lkml/20190206175627.GA20399@gmail.com/ +Suggested-by: Martin Sebor +Acked-by: Jessica Yu +Signed-off-by: Miguel Ojeda +--- + include/linux/module.h | 4 ++-- + 1 file changed, 2 insertions(+), 2 deletions(-) + +diff --git a/include/linux/module.h b/include/linux/module.h +index 8fa38d3e7538..f5bc4c046461 100644 +--- a/include/linux/module.h ++++ b/include/linux/module.h +@@ -129,13 +129,13 @@ extern void cleanup_module(void); + #define module_init(initfn) \ + static inline initcall_t __maybe_unused __inittest(void) \ + { return initfn; } \ +- int init_module(void) __attribute__((alias(#initfn))); ++ int init_module(void) __attribute__((__copy__(initfn))) __attribute__((alias(#initfn))); + + /* This is only required if you want to be unloadable. */ + #define module_exit(exitfn) \ + static inline exitcall_t __maybe_unused __exittest(void) \ + { return exitfn; } \ +- void cleanup_module(void) __attribute__((alias(#exitfn))); ++ void cleanup_module(void) __attribute__((__copy__(exitfn))) __attribute__((alias(#exitfn))); + + #endif + +EOF + ;; + *) # CentOS 6.x and 7.x + patch -p1 <<'EOF' +--- linux-3.10.0-1127.el7/include/linux/init.h.orig 2020-05-09 20:55:48.638956513 -0700 ++++ linux-3.10.0-1127.el7/include/linux/init.h 2020-05-09 20:56:46.947612445 -0700 +@@ -309,13 +309,15 @@ + #define module_init(initfn) \ + static inline initcall_t __inittest(void) \ + { return initfn; } \ +- int init_module(void) __attribute__((alias(#initfn))); ++ int init_module(void) __attribute__((__copy__(initfn))) \ ++ __attribute__((alias(#initfn))); + + /* This is only required if you want to be unloadable. */ + #define module_exit(exitfn) \ + static inline exitcall_t __exittest(void) \ + { return exitfn; } \ +- void cleanup_module(void) __attribute__((alias(#exitfn))); ++ void cleanup_module(void) __attribute__((__copy__(exitfn)))\ ++ __attribute__((alias(#exitfn))); + + #define __setup_param(str, unique_id, fn) /* nothing */ + #define __setup(str, func) /* nothing */ +EOF + ;; + esac + # Use sed to patch the ____ilog2_NaN() prototype. sed -i 's/__attribute__((const, noreturn))/__attribute__((noreturn))/' \ include/linux/log2.h tools/include/linux/log2.h 2>/dev/null