From 8793bb7f4a9dd1396575d2e9337d331662cb7555 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 19 Jun 2018 13:14:56 -0700 Subject: [PATCH 1/9] kbuild: add macro for controlling warnings to linux/compiler.h I have occasionally run into a situation where it would make sense to control a compiler warning from a source file rather than doing so from a Makefile using the $(cc-disable-warning, ...) or $(cc-option, ...) helpers. The approach here is similar to what glibc uses, using __diag() and related macros to encapsulate a _Pragma("GCC diagnostic ...") statement that gets turned into the respective "#pragma GCC diagnostic ..." by the preprocessor when the macro gets expanded. Like glibc, I also have an argument to pass the affected compiler version, but decided to actually evaluate that one. For now, this supports GCC_4_6, GCC_4_7, GCC_4_8, GCC_4_9, GCC_5, GCC_6, GCC_7, GCC_8 and GCC_9. Adding support for CLANG_5 and other interesting versions is straightforward here. GNU compilers starting with gcc-4.2 could support it in principle, but "#pragma GCC diagnostic push" was only added in gcc-4.6, so it seems simpler to not deal with those at all. The same versions show a large number of warnings already, so it seems easier to just leave it at that and not do a more fine-grained control for them. The use cases I found so far include: - turning off the gcc-8 -Wattribute-alias warning inside of the SYSCALL_DEFINEx() macro without having to do it globally. - Reducing the build time for a simple re-make after a change, once we move the warnings from ./Makefile and ./scripts/Makefile.extrawarn into linux/compiler.h - More control over the warnings based on other configurations, using preprocessor syntax instead of Makefile syntax. This should make it easier for the average developer to understand and change things. - Adding an easy way to turn the W=1 option on unconditionally for a subdirectory or a specific file. This has been requested by several developers in the past that want to have their subsystems W=1 clean. - Integrating clang better into the build systems. Clang supports more warnings than GCC, and we probably want to classify them as default, W=1, W=2 etc, but there are cases in which the warnings should be classified differently due to excessive false positives from one or the other compiler. - Adding a way to turn the default warnings into errors (e.g. using a new "make E=0" tag) while not also turning the W=1 warnings into errors. This patch for now just adds the minimal infrastructure in order to do the first of the list above. As the #pragma GCC diagnostic takes precedence over command line options, the next step would be to convert a lot of the individual Makefiles that set nonstandard options to use __diag() instead. [paul.burton@mips.com: - Rebase atop current master. - Add __diag_GCC, or more generally __diag_, abstraction to avoid code outside of linux/compiler-gcc.h needing to duplicate knowledge about different GCC versions. - Add a comment argument to __diag_{ignore,warn,error} which isn't used in the expansion of the macros but serves to push people to document the reason for using them - per feedback from Kees Cook. - Translate severity to GCC-specific pragmas in linux/compiler-gcc.h rather than using GCC-specific in linux/compiler_types.h. - Drop all but GCC 8 macros, since we only need to define macros for versions that we need to introduce pragmas for, and as of this series that's just GCC 8. - Capitalize comments in linux/compiler-gcc.h to match the style of the rest of the file. - Line up macro definitions with tabs in linux/compiler-gcc.h.] Signed-off-by: Arnd Bergmann Signed-off-by: Paul Burton Tested-by: Christophe Leroy Tested-by: Stafford Horne Signed-off-by: Masahiro Yamada --- include/linux/compiler-gcc.h | 25 +++++++++++++++++++++++++ include/linux/compiler_types.h | 18 ++++++++++++++++++ 2 files changed, 43 insertions(+) diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h index f1a7492a5cc8..fd282c7d3e5e 100644 --- a/include/linux/compiler-gcc.h +++ b/include/linux/compiler-gcc.h @@ -347,3 +347,28 @@ #if GCC_VERSION >= 50100 #define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1 #endif + +/* + * Turn individual warnings and errors on and off locally, depending + * on version. + */ +#define __diag_GCC(version, severity, s) \ + __diag_GCC_ ## version(__diag_GCC_ ## severity s) + +/* Severity used in pragma directives */ +#define __diag_GCC_ignore ignored +#define __diag_GCC_warn warning +#define __diag_GCC_error error + +/* Compilers before gcc-4.6 do not understand "#pragma GCC diagnostic push" */ +#if GCC_VERSION >= 40600 +#define __diag_str1(s) #s +#define __diag_str(s) __diag_str1(s) +#define __diag(s) _Pragma(__diag_str(GCC diagnostic s)) +#endif + +#if GCC_VERSION >= 80000 +#define __diag_GCC_8(s) __diag(s) +#else +#define __diag_GCC_8(s) +#endif diff --git a/include/linux/compiler_types.h b/include/linux/compiler_types.h index 6b79a9bba9a7..a8ba6b04152c 100644 --- a/include/linux/compiler_types.h +++ b/include/linux/compiler_types.h @@ -271,4 +271,22 @@ struct ftrace_likely_data { # define __native_word(t) (sizeof(t) == sizeof(char) || sizeof(t) == sizeof(short) || sizeof(t) == sizeof(int) || sizeof(t) == sizeof(long)) #endif +#ifndef __diag +#define __diag(string) +#endif + +#ifndef __diag_GCC +#define __diag_GCC(version, severity, string) +#endif + +#define __diag_push() __diag(push) +#define __diag_pop() __diag(pop) + +#define __diag_ignore(compiler, version, option, comment) \ + __diag_ ## compiler(version, ignore, option) +#define __diag_warn(compiler, version, option, comment) \ + __diag_ ## compiler(version, warn, option) +#define __diag_error(compiler, version, option, comment) \ + __diag_ ## compiler(version, error, option) + #endif /* __LINUX_COMPILER_TYPES_H */ From bee20031772af3debe8cbaa234528f24c7892e8f Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 19 Jun 2018 13:14:57 -0700 Subject: [PATCH 2/9] disable -Wattribute-alias warning for SYSCALL_DEFINEx() gcc-8 warns for every single definition of a system call entry point, e.g.: include/linux/compat.h:56:18: error: 'compat_sys_rt_sigprocmask' alias between functions of incompatible types 'long int(int, compat_sigset_t *, compat_sigset_t *, compat_size_t)' {aka 'long int(int, struct *, struct *, unsigned int)'} and 'long int(long int, long int, long int, long int)' [-Werror=attribute-alias] asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))\ ^~~~~~~~~~ include/linux/compat.h:45:2: note: in expansion of macro 'COMPAT_SYSCALL_DEFINEx' COMPAT_SYSCALL_DEFINEx(4, _##name, __VA_ARGS__) ^~~~~~~~~~~~~~~~~~~~~~ kernel/signal.c:2601:1: note: in expansion of macro 'COMPAT_SYSCALL_DEFINE4' COMPAT_SYSCALL_DEFINE4(rt_sigprocmask, int, how, compat_sigset_t __user *, nset, ^~~~~~~~~~~~~~~~~~~~~~ include/linux/compat.h:60:18: note: aliased declaration here asmlinkage long compat_SyS##name(__MAP(x,__SC_LONG,__VA_ARGS__))\ ^~~~~~~~~~ The new warning seems reasonable in principle, but it doesn't help us here, since we rely on the type mismatch to sanitize the system call arguments. After I reported this as GCC PR82435, a new -Wno-attribute-alias option was added that could be used to turn the warning off globally on the command line, but I'd prefer to do it a little more fine-grained. Interestingly, turning a warning off and on again inside of a single macro doesn't always work, in this case I had to add an extra statement inbetween and decided to copy the __SC_TEST one from the native syscall to the compat syscall macro. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83256 for more details about this. [paul.burton@mips.com: - Rebase atop current master. - Split GCC & version arguments to __diag_ignore() in order to match changes to the preceding patch. - Add the comment argument to match the preceding patch.] Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82435 Signed-off-by: Arnd Bergmann Signed-off-by: Paul Burton Tested-by: Christophe Leroy Tested-by: Stafford Horne Signed-off-by: Masahiro Yamada --- include/linux/compat.h | 8 +++++++- include/linux/syscalls.h | 4 ++++ 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/include/linux/compat.h b/include/linux/compat.h index b1a5562b3215..c68acc47da57 100644 --- a/include/linux/compat.h +++ b/include/linux/compat.h @@ -72,6 +72,9 @@ */ #ifndef COMPAT_SYSCALL_DEFINEx #define COMPAT_SYSCALL_DEFINEx(x, name, ...) \ + __diag_push(); \ + __diag_ignore(GCC, 8, "-Wattribute-alias", \ + "Type aliasing is used to sanitize syscall arguments");\ asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)); \ asmlinkage long compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \ __attribute__((alias(__stringify(__se_compat_sys##name)))); \ @@ -80,8 +83,11 @@ asmlinkage long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \ asmlinkage long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)) \ { \ - return __do_compat_sys##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));\ + long ret = __do_compat_sys##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));\ + __MAP(x,__SC_TEST,__VA_ARGS__); \ + return ret; \ } \ + __diag_pop(); \ static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) #endif /* COMPAT_SYSCALL_DEFINEx */ diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 73810808cdf2..a368a68cb667 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -231,6 +231,9 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event) */ #ifndef __SYSCALL_DEFINEx #define __SYSCALL_DEFINEx(x, name, ...) \ + __diag_push(); \ + __diag_ignore(GCC, 8, "-Wattribute-alias", \ + "Type aliasing is used to sanitize syscall arguments");\ asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) \ __attribute__((alias(__stringify(__se_sys##name)))); \ ALLOW_ERROR_INJECTION(sys##name, ERRNO); \ @@ -243,6 +246,7 @@ static inline int is_syscall_trace_event(struct trace_event_call *tp_event) __PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__)); \ return ret; \ } \ + __diag_pop(); \ static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__)) #endif /* __SYSCALL_DEFINEx */ From ac8517440344dbe598f7c1c23e686c800b563061 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Tue, 19 Jun 2018 13:14:58 -0700 Subject: [PATCH 3/9] powerpc: Remove -Wattribute-alias pragmas With SYSCALL_DEFINEx() disabling -Wattribute-alias generically, there's no need to duplicate that for PowerPC syscalls. This reverts commit 415520373975 ("powerpc: fix build failure by disabling attribute-alias warning in pci_32") and commit 2479bfc9bc60 ("powerpc: Fix build by disabling attribute-alias warning for SYSCALL_DEFINEx"). Signed-off-by: Paul Burton Acked-by: Christophe Leroy Acked-by: Michael Ellerman Signed-off-by: Masahiro Yamada --- arch/powerpc/kernel/pci_32.c | 4 ---- arch/powerpc/kernel/pci_64.c | 4 ---- arch/powerpc/kernel/rtas.c | 4 ---- arch/powerpc/kernel/signal_32.c | 8 -------- arch/powerpc/kernel/signal_64.c | 4 ---- arch/powerpc/kernel/syscalls.c | 4 ---- arch/powerpc/mm/subpage-prot.c | 4 ---- 7 files changed, 32 deletions(-) diff --git a/arch/powerpc/kernel/pci_32.c b/arch/powerpc/kernel/pci_32.c index 4f861055a852..d63b488d34d7 100644 --- a/arch/powerpc/kernel/pci_32.c +++ b/arch/powerpc/kernel/pci_32.c @@ -285,9 +285,6 @@ pci_bus_to_hose(int bus) * Note that the returned IO or memory base is a physical address */ -#pragma GCC diagnostic push -#pragma GCC diagnostic ignored "-Wpragmas" -#pragma GCC diagnostic ignored "-Wattribute-alias" SYSCALL_DEFINE3(pciconfig_iobase, long, which, unsigned long, bus, unsigned long, devfn) { @@ -313,4 +310,3 @@ SYSCALL_DEFINE3(pciconfig_iobase, long, which, return result; } -#pragma GCC diagnostic pop diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c index 812171c09f42..dff28f903512 100644 --- a/arch/powerpc/kernel/pci_64.c +++ b/arch/powerpc/kernel/pci_64.c @@ -203,9 +203,6 @@ void pcibios_setup_phb_io_space(struct pci_controller *hose) #define IOBASE_ISA_IO 3 #define IOBASE_ISA_MEM 4 -#pragma GCC diagnostic push -#pragma GCC diagnostic ignored "-Wpragmas" -#pragma GCC diagnostic ignored "-Wattribute-alias" SYSCALL_DEFINE3(pciconfig_iobase, long, which, unsigned long, in_bus, unsigned long, in_devfn) { @@ -259,7 +256,6 @@ SYSCALL_DEFINE3(pciconfig_iobase, long, which, unsigned long, in_bus, return -EOPNOTSUPP; } -#pragma GCC diagnostic pop #ifdef CONFIG_NUMA int pcibus_to_node(struct pci_bus *bus) diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c index 7fb9f83dcde8..8afd146bc9c7 100644 --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -1051,9 +1051,6 @@ struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log, } /* We assume to be passed big endian arguments */ -#pragma GCC diagnostic push -#pragma GCC diagnostic ignored "-Wpragmas" -#pragma GCC diagnostic ignored "-Wattribute-alias" SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs) { struct rtas_args args; @@ -1140,7 +1137,6 @@ SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs) return 0; } -#pragma GCC diagnostic pop /* * Call early during boot, before mem init, to retrieve the RTAS diff --git a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c index 5eedbb282d42..e6474a45cef5 100644 --- a/arch/powerpc/kernel/signal_32.c +++ b/arch/powerpc/kernel/signal_32.c @@ -1038,9 +1038,6 @@ static int do_setcontext_tm(struct ucontext __user *ucp, } #endif -#pragma GCC diagnostic push -#pragma GCC diagnostic ignored "-Wpragmas" -#pragma GCC diagnostic ignored "-Wattribute-alias" #ifdef CONFIG_PPC64 COMPAT_SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, struct ucontext __user *, new_ctx, int, ctx_size) @@ -1134,7 +1131,6 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, set_thread_flag(TIF_RESTOREALL); return 0; } -#pragma GCC diagnostic pop #ifdef CONFIG_PPC64 COMPAT_SYSCALL_DEFINE0(rt_sigreturn) @@ -1231,9 +1227,6 @@ SYSCALL_DEFINE0(rt_sigreturn) return 0; } -#pragma GCC diagnostic push -#pragma GCC diagnostic ignored "-Wpragmas" -#pragma GCC diagnostic ignored "-Wattribute-alias" #ifdef CONFIG_PPC32 SYSCALL_DEFINE3(debug_setcontext, struct ucontext __user *, ctx, int, ndbg, struct sig_dbg_op __user *, dbg) @@ -1337,7 +1330,6 @@ SYSCALL_DEFINE3(debug_setcontext, struct ucontext __user *, ctx, return 0; } #endif -#pragma GCC diagnostic pop /* * OK, we're invoking a handler diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c index d42b60020389..83d51bf586c7 100644 --- a/arch/powerpc/kernel/signal_64.c +++ b/arch/powerpc/kernel/signal_64.c @@ -625,9 +625,6 @@ static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp) /* * Handle {get,set,swap}_context operations */ -#pragma GCC diagnostic push -#pragma GCC diagnostic ignored "-Wpragmas" -#pragma GCC diagnostic ignored "-Wattribute-alias" SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, struct ucontext __user *, new_ctx, long, ctx_size) { @@ -693,7 +690,6 @@ SYSCALL_DEFINE3(swapcontext, struct ucontext __user *, old_ctx, set_thread_flag(TIF_RESTOREALL); return 0; } -#pragma GCC diagnostic pop /* diff --git a/arch/powerpc/kernel/syscalls.c b/arch/powerpc/kernel/syscalls.c index 083fa06962fd..466216506eb2 100644 --- a/arch/powerpc/kernel/syscalls.c +++ b/arch/powerpc/kernel/syscalls.c @@ -62,9 +62,6 @@ out: return ret; } -#pragma GCC diagnostic push -#pragma GCC diagnostic ignored "-Wpragmas" -#pragma GCC diagnostic ignored "-Wattribute-alias" SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len, unsigned long, prot, unsigned long, flags, unsigned long, fd, unsigned long, pgoff) @@ -78,7 +75,6 @@ SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len, { return do_mmap2(addr, len, prot, flags, fd, offset, PAGE_SHIFT); } -#pragma GCC diagnostic pop #ifdef CONFIG_PPC32 /* diff --git a/arch/powerpc/mm/subpage-prot.c b/arch/powerpc/mm/subpage-prot.c index 75cb646a79c3..9d16ee251fc0 100644 --- a/arch/powerpc/mm/subpage-prot.c +++ b/arch/powerpc/mm/subpage-prot.c @@ -186,9 +186,6 @@ static void subpage_mark_vma_nohuge(struct mm_struct *mm, unsigned long addr, * in a 2-bit field won't allow writes to a page that is otherwise * write-protected. */ -#pragma GCC diagnostic push -#pragma GCC diagnostic ignored "-Wpragmas" -#pragma GCC diagnostic ignored "-Wattribute-alias" SYSCALL_DEFINE3(subpage_prot, unsigned long, addr, unsigned long, len, u32 __user *, map) { @@ -272,4 +269,3 @@ SYSCALL_DEFINE3(subpage_prot, unsigned long, addr, up_write(&mm->mmap_sem); return err; } -#pragma GCC diagnostic pop From 5391e536dbf702de6581369e47c9c4cea3a87170 Mon Sep 17 00:00:00 2001 From: Sven Joachim Date: Mon, 18 Jun 2018 19:45:25 +0200 Subject: [PATCH 4/9] stack-protector: Fix test with 32-bit userland and CONFIG_64BIT=y When building a 64-bit 4.18-rc1 kernel with a 32-bit userland, I noticed that stack protection was silently disabled. Adding -m64 in gcc-x86_64-has-stack-protector.sh fixed that, similar to what has been noticed in commit 2a61f4747eea ("stack-protector: test compiler capability in Kconfig and drop AUTO mode") for gcc-x86_32-has-stack-protector.sh. Signed-off-by: Sven Joachim Signed-off-by: Masahiro Yamada --- scripts/gcc-x86_64-has-stack-protector.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/scripts/gcc-x86_64-has-stack-protector.sh b/scripts/gcc-x86_64-has-stack-protector.sh index 3755af0cd9f7..75e4e22b986a 100755 --- a/scripts/gcc-x86_64-has-stack-protector.sh +++ b/scripts/gcc-x86_64-has-stack-protector.sh @@ -1,4 +1,4 @@ #!/bin/sh # SPDX-License-Identifier: GPL-2.0 -echo "int foo(void) { char X[200]; return 3; }" | $* -S -x c -c -O0 -mcmodel=kernel -fno-PIE -fstack-protector - -o - 2> /dev/null | grep -q "%gs" +echo "int foo(void) { char X[200]; return 3; }" | $* -S -x c -c -m64 -O0 -mcmodel=kernel -fno-PIE -fstack-protector - -o - 2> /dev/null | grep -q "%gs" From b2d00d7c61c84edd150310af3f556f8a3c6e2e67 Mon Sep 17 00:00:00 2001 From: Dirk Gouders Date: Thu, 21 Jun 2018 15:30:54 +0200 Subject: [PATCH 5/9] kconfig: fix line numbers for if-entries in menu tree The line numers for if-entries in the menu tree are off by one or more lines which is confusing when debugging for correctness of unrelated changes. According to the git log, commit a02f0570ae201c49 (kconfig: improve error handling in the parser) was the last one that changed that part of the parser and replaced "if_entry: T_IF expr T_EOL" by "if_entry: T_IF expr nl" but the commit message does not state why this has been done. When reverting that part of the commit, only the line numers are corrected (checked with cdebug = DEBUG_PARSE in zconf.y), otherwise the menu tree remains unchanged (checked with zconfdump() enabled in conf.c). An example for the corrected line numbers: drivers/soc/Kconfig:15:source drivers/soc/tegra/Kconfig drivers/soc/tegra/Kconfig:4:if drivers/soc/tegra/Kconfig:6:if changes to: drivers/soc/Kconfig:15:source drivers/soc/tegra/Kconfig drivers/soc/tegra/Kconfig:1:if drivers/soc/tegra/Kconfig:4:if Signed-off-by: Dirk Gouders Signed-off-by: Masahiro Yamada --- scripts/kconfig/zconf.y | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/scripts/kconfig/zconf.y b/scripts/kconfig/zconf.y index 6f9b0aa32a82..ed84d4a8e288 100644 --- a/scripts/kconfig/zconf.y +++ b/scripts/kconfig/zconf.y @@ -31,7 +31,7 @@ struct symbol *symbol_hash[SYMBOL_HASHSIZE]; static struct menu *current_menu, *current_entry; %} -%expect 32 +%expect 31 %union { @@ -337,7 +337,7 @@ choice_block: /* if entry */ -if_entry: T_IF expr nl +if_entry: T_IF expr T_EOL { printd(DEBUG_PARSE, "%s:%d:if\n", zconf_curname(), zconf_lineno()); menu_add_entry(NULL); From bdb60101df4a2999608430112a5abfb78628db1e Mon Sep 17 00:00:00 2001 From: Randy Dunlap Date: Fri, 22 Jun 2018 20:08:21 -0700 Subject: [PATCH 6/9] kconfig: document Kconfig source file comments I saw this type of Kconfig construct on LKML: config SYMBOOL #bool "prompt string" default y and wondered what it does. Then I wondered if '#' comments are even documented. They aren't, so add a little doc for that. Ah, good. kconfig says: arch/x86/Kconfig:2942:warning: config symbol defined without type Signed-off-by: Randy Dunlap Signed-off-by: Masahiro Yamada --- Documentation/kbuild/kconfig-language.txt | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/Documentation/kbuild/kconfig-language.txt b/Documentation/kbuild/kconfig-language.txt index 3534a84d206c..64e0775a62d4 100644 --- a/Documentation/kbuild/kconfig-language.txt +++ b/Documentation/kbuild/kconfig-language.txt @@ -430,6 +430,12 @@ This sets the config program's title bar if the config program chooses to use it. It should be placed at the top of the configuration, before any other statement. +'#' Kconfig source file comment: + +An unquoted '#' character anywhere in a source file line indicates +the beginning of a source file comment. The remainder of that line +is a comment. + Kconfig hints ------------- From ecd53ac2f2c6e42fe732d0aa282192cb6ad3faea Mon Sep 17 00:00:00 2001 From: Dirk Gouders Date: Fri, 22 Jun 2018 21:27:38 +0200 Subject: [PATCH 7/9] kconfig: handle P_SYMBOL in print_symbol() Each symbol has a property of type P_SYMBOL since commit 59e89e3ddf85 (kconfig: save location of config symbols). Handle those properties in print_symbol(). Further, place a pointer to print_symbol() in the comment above the list of known property type. Signed-off-by: Dirk Gouders Signed-off-by: Masahiro Yamada --- scripts/kconfig/expr.h | 3 +++ scripts/kconfig/zconf.y | 4 ++++ 2 files changed, 7 insertions(+) diff --git a/scripts/kconfig/expr.h b/scripts/kconfig/expr.h index 94a383b21df6..f63b41b0dd49 100644 --- a/scripts/kconfig/expr.h +++ b/scripts/kconfig/expr.h @@ -171,6 +171,9 @@ struct symbol { * config BAZ * int "BAZ Value" * range 1..255 + * + * Please, also check zconf.y:print_symbol() when modifying the + * list of property types! */ enum prop_type { P_UNKNOWN, diff --git a/scripts/kconfig/zconf.y b/scripts/kconfig/zconf.y index ed84d4a8e288..4b68272ebdb9 100644 --- a/scripts/kconfig/zconf.y +++ b/scripts/kconfig/zconf.y @@ -717,6 +717,10 @@ static void print_symbol(FILE *out, struct menu *menu) print_quoted_string(out, prop->text); fputc('\n', out); break; + case P_SYMBOL: + fputs( " symbol ", out); + fprintf(out, "%s\n", prop->sym->name); + break; default: fprintf(out, " unknown prop %d!\n", prop->type); break; From 8b9d27124094964b3c4f8985ba66355ac4d9e842 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sun, 24 Jun 2018 01:41:51 +0900 Subject: [PATCH 8/9] kbuild: reword help of LD_DEAD_CODE_DATA_ELIMINATION Since commit 5d20ee3192a5 ("kbuild: Allow LD_DEAD_CODE_DATA_ELIMINATION to be selectable if enabled"), HAVE_LD_DEAD_CODE_DATA_ELIMINATION is supposed to be selected by architectures that are capable of this functionality. LD_DEAD_CODE_DATA_ELIMINATION is now users' selection. Update the help message. Signed-off-by: Masahiro Yamada --- init/Kconfig | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/init/Kconfig b/init/Kconfig index 5a52f07259a2..eaad1536647f 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1051,10 +1051,9 @@ config LD_DEAD_CODE_DATA_ELIMINATION depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION depends on EXPERT help - Select this if the architecture wants to do dead code and - data elimination with the linker by compiling with - -ffunction-sections -fdata-sections, and linking with - --gc-sections. + Enable this if you want to do dead code and data elimination with + the linker by compiling with -ffunction-sections -fdata-sections, + and linking with --gc-sections. This can reduce on disk and in-memory size of the kernel code and static data, particularly for small configs and From 73d1c580f92b203f4c3a189ee98c917c65712f7e Mon Sep 17 00:00:00 2001 From: Jerry James Date: Sat, 23 Jun 2018 22:49:04 +0200 Subject: [PATCH 9/9] kconfig: loop boundary condition fix If buf[-1] just happens to hold the byte 0x0A, then nread can wrap around to (size_t)-1, leading to invalid memory accesses. This has caused segmentation faults when trying to build the latest kernel snapshots for i686 in Fedora: https://bugzilla.redhat.com/show_bug.cgi?id=1592374 Signed-off-by: Jerry James [alexpl@fedoraproject.org: reformatted patch for submission] Signed-off-by: Alexander Ploumistos Signed-off-by: Masahiro Yamada --- scripts/kconfig/preprocess.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/scripts/kconfig/preprocess.c b/scripts/kconfig/preprocess.c index 65da87fce907..5ca2df790d3c 100644 --- a/scripts/kconfig/preprocess.c +++ b/scripts/kconfig/preprocess.c @@ -156,7 +156,7 @@ static char *do_shell(int argc, char *argv[]) nread--; /* remove trailing new lines */ - while (buf[nread - 1] == '\n') + while (nread > 0 && buf[nread - 1] == '\n') nread--; buf[nread] = 0;