From: Greg Kroah-Hartman Date: Mon, 5 Aug 2019 11:44:13 +0000 (+0200) Subject: 4.9-stable patches X-Git-Tag: v4.4.188~7 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=dd90867d10b32bc31a772f230d406d72a1ec19c8;p=thirdparty%2Fkernel%2Fstable-queue.git 4.9-stable patches added patches: backport-minimal-compiler_attributes.h-to-support-gcc-9.patch include-linux-module.h-copy-__init-__exit-attrs-to-init-cleanup_module.patch objtool-support-gcc-9-cold-subfunction-naming-scheme.patch --- diff --git a/queue-4.9/backport-minimal-compiler_attributes.h-to-support-gcc-9.patch b/queue-4.9/backport-minimal-compiler_attributes.h-to-support-gcc-9.patch new file mode 100644 index 00000000000..0fe054bbd14 --- /dev/null +++ b/queue-4.9/backport-minimal-compiler_attributes.h-to-support-gcc-9.patch @@ -0,0 +1,48 @@ +From miguel.ojeda.sandonis@gmail.com Mon Aug 5 13:30:44 2019 +From: Miguel Ojeda +Date: Fri, 2 Aug 2019 12:37:56 +0200 +Subject: Backport minimal compiler_attributes.h to support GCC 9 +To: Greg Kroah-Hartman +Cc: stable@vger.kernel.org, Miguel Ojeda +Message-ID: <20190802103757.31397-1-miguel.ojeda.sandonis@gmail.com> + +From: Miguel Ojeda + +This adds support for __copy to v4.9.y so that we can use it in +init/exit_module to avoid -Werror=missing-attributes errors on GCC 9. + +Link: https://lore.kernel.org/lkml/259986242.BvXPX32bHu@devpool35/ +Cc: +Suggested-by: Rolf Eike Beer +Signed-off-by: Miguel Ojeda +Signed-off-by: Greg Kroah-Hartman + +--- + include/linux/compiler.h | 16 ++++++++++++++++ + 1 file changed, 16 insertions(+) + +--- a/include/linux/compiler.h ++++ b/include/linux/compiler.h +@@ -54,6 +54,22 @@ extern void __chk_io_ptr(const volatile + + #ifdef __KERNEL__ + ++/* ++ * Minimal backport of compiler_attributes.h to add support for __copy ++ * to v4.9.y so that we can use it in init/exit_module to avoid ++ * -Werror=missing-attributes errors on GCC 9. ++ */ ++#ifndef __has_attribute ++# define __has_attribute(x) __GCC4_has_attribute_##x ++# define __GCC4_has_attribute___copy__ 0 ++#endif ++ ++#if __has_attribute(__copy__) ++# define __copy(symbol) __attribute__((__copy__(symbol))) ++#else ++# define __copy(symbol) ++#endif ++ + #ifdef __GNUC__ + #include + #endif diff --git a/queue-4.9/include-linux-module.h-copy-__init-__exit-attrs-to-init-cleanup_module.patch b/queue-4.9/include-linux-module.h-copy-__init-__exit-attrs-to-init-cleanup_module.patch new file mode 100644 index 00000000000..293c44e015d --- /dev/null +++ b/queue-4.9/include-linux-module.h-copy-__init-__exit-attrs-to-init-cleanup_module.patch @@ -0,0 +1,84 @@ +From miguel.ojeda.sandonis@gmail.com Mon Aug 5 13:31:00 2019 +From: Miguel Ojeda +Date: Fri, 2 Aug 2019 12:37:57 +0200 +Subject: include/linux/module.h: copy __init/__exit attrs to init/cleanup_module +To: Greg Kroah-Hartman +Cc: stable@vger.kernel.org, Miguel Ojeda +Message-ID: <20190802103757.31397-2-miguel.ojeda.sandonis@gmail.com> + +From: Miguel Ojeda + +commit a6e60d84989fa0e91db7f236eda40453b0e44afa upstream. + +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/259986242.BvXPX32bHu@devpool35/ +Cc: +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 +Signed-off-by: Greg Kroah-Hartman + +--- + include/linux/module.h | 4 ++-- + 1 file changed, 2 insertions(+), 2 deletions(-) + +--- 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) __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) __copy(exitfn) __attribute__((alias(#exitfn))); + + #endif + diff --git a/queue-4.9/objtool-support-gcc-9-cold-subfunction-naming-scheme.patch b/queue-4.9/objtool-support-gcc-9-cold-subfunction-naming-scheme.patch new file mode 100644 index 00000000000..cb2cb7e6130 --- /dev/null +++ b/queue-4.9/objtool-support-gcc-9-cold-subfunction-naming-scheme.patch @@ -0,0 +1,51 @@ +From bcb6fb5da77c2a228adf07cc9cb1a0c2aa2001c6 Mon Sep 17 00:00:00 2001 +From: Josh Poimboeuf +Date: Wed, 31 Oct 2018 21:57:30 -0500 +Subject: objtool: Support GCC 9 cold subfunction naming scheme + +From: Josh Poimboeuf + +commit bcb6fb5da77c2a228adf07cc9cb1a0c2aa2001c6 upstream. + +Starting with GCC 8, a lot of unlikely code was moved out of line to +"cold" subfunctions in .text.unlikely. + +For example, the unlikely bits of: + + irq_do_set_affinity() + +are moved out to the following subfunction: + + irq_do_set_affinity.cold.49() + +Starting with GCC 9, the numbered suffix has been removed. So in the +above example, the cold subfunction is instead: + + irq_do_set_affinity.cold() + +Tweak the objtool subfunction detection logic so that it detects both +GCC 8 and GCC 9 naming schemes. + +Reported-by: Peter Zijlstra (Intel) +Signed-off-by: Josh Poimboeuf +Signed-off-by: Thomas Gleixner +Tested-by: Peter Zijlstra (Intel) +Acked-by: Peter Zijlstra (Intel) +Link: https://lkml.kernel.org/r/015e9544b1f188d36a7f02fa31e9e95629aa5f50.1541040800.git.jpoimboe@redhat.com +Signed-off-by: Greg Kroah-Hartman + +--- + tools/objtool/elf.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +--- a/tools/objtool/elf.c ++++ b/tools/objtool/elf.c +@@ -305,7 +305,7 @@ static int read_symbols(struct elf *elf) + if (sym->type != STT_FUNC) + continue; + sym->pfunc = sym->cfunc = sym; +- coldstr = strstr(sym->name, ".cold."); ++ coldstr = strstr(sym->name, ".cold"); + if (!coldstr) + continue; + diff --git a/queue-4.9/series b/queue-4.9/series index fb17a087463..0541ac83a02 100644 --- a/queue-4.9/series +++ b/queue-4.9/series @@ -36,3 +36,6 @@ coredump-fix-race-condition-between-mmget_not_zero-get_task_mm-and-core-dumping. infiniband-fix-race-condition-between-infiniband-mlx4-mlx5-driver-and-core-dumping.patch coredump-fix-race-condition-between-collapse_huge_page-and-core-dumping.patch eeprom-at24-make-spd-world-readable-again.patch +backport-minimal-compiler_attributes.h-to-support-gcc-9.patch +include-linux-module.h-copy-__init-__exit-attrs-to-init-cleanup_module.patch +objtool-support-gcc-9-cold-subfunction-naming-scheme.patch