Merge tag 'kbuild-fixes-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

torvalds · torvalds · commit 22d3e0c36e10 · 2018-06-30T13:05:30.000-07:00
Pull Kbuild fixes from Masahiro Yamada:

 - introduce __diag_* macros and suppress -Wattribute-alias warnings
   from GCC 8

 - fix stack protector test script for x86_64

 - fix line number handling in Kconfig

 - document that '#' starts a comment in Kconfig

 - handle P_SYMBOL property in dump debugging of Kconfig

 - correct help message of LD_DEAD_CODE_DATA_ELIMINATION

 - fix occasional segmentation faults in Kconfig

* tag 'kbuild-fixes-v4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: loop boundary condition fix
  kbuild: reword help of LD_DEAD_CODE_DATA_ELIMINATION
  kconfig: handle P_SYMBOL in print_symbol()
  kconfig: document Kconfig source file comments
  kconfig: fix line numbers for if-entries in menu tree
  stack-protector: Fix test with 32-bit userland and CONFIG_64BIT=y
  powerpc: Remove -Wattribute-alias pragmas
  disable -Wattribute-alias warning for SYSCALL_DEFINEx()
  kbuild: add macro for controlling warnings to linux/compiler.h
diff --git 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
 -------------
diff --git 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
@@ -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
@@ -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
@@ -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
@@ -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
@@ -62,9 +62,6 @@ static inline long do_mmap2(unsigned long addr, size_t len,
 	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
@@ -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
diff --git 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/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
@@ -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 */
diff --git 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 */
 
diff --git 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
diff --git 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"
diff --git 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/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;
diff --git 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);
@@ -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;

Original file line number	Diff line number	Diff line change
`@@ -285,9 +285,6 @@ pci_bus_to_hose(int bus)`
`285`	`285`	`* Note that the returned IO or memory base is a physical address`
`286`	`286`	`*/`
`287`	`287`
`288`		`-#pragma GCC diagnostic push`
`289`		`-#pragma GCC diagnostic ignored "-Wpragmas"`
`290`		`-#pragma GCC diagnostic ignored "-Wattribute-alias"`
`291`	`288`	`SYSCALL_DEFINE3(pciconfig_iobase, long, which,`
`292`	`289`	`unsigned long, bus, unsigned long, devfn)`
`293`	`290`	`{`
`@@ -313,4 +310,3 @@ SYSCALL_DEFINE3(pciconfig_iobase, long, which,`
`313`	`310`
`314`	`311`	`return result;`
`315`	`312`	`}`
`316`		`-#pragma GCC diagnostic pop`
Original file line number	Diff line number	Diff line change
`@@ -203,9 +203,6 @@ void pcibios_setup_phb_io_space(struct pci_controller *hose)`
`203`	`203`	`#define IOBASE_ISA_IO 3`
`204`	`204`	`#define IOBASE_ISA_MEM 4`
`205`	`205`
`206`		`-#pragma GCC diagnostic push`
`207`		`-#pragma GCC diagnostic ignored "-Wpragmas"`
`208`		`-#pragma GCC diagnostic ignored "-Wattribute-alias"`
`209`	`206`	`SYSCALL_DEFINE3(pciconfig_iobase, long, which, unsigned long, in_bus,`
`210`	`207`	`unsigned long, in_devfn)`
`211`	`208`	`{`
`@@ -259,7 +256,6 @@ SYSCALL_DEFINE3(pciconfig_iobase, long, which, unsigned long, in_bus,`
`259`	`256`
`260`	`257`	`return -EOPNOTSUPP;`
`261`	`258`	`}`
`262`		`-#pragma GCC diagnostic pop`
`263`	`259`
`264`	`260`	`#ifdef CONFIG_NUMA`
`265`	`261`	`int pcibus_to_node(struct pci_bus *bus)`
Original file line number	Diff line number	Diff line change
`@@ -1051,9 +1051,6 @@ struct pseries_errorlog get_pseries_errorlog(struct rtas_error_log log,`
`1051`	`1051`	`}`
`1052`	`1052`
`1053`	`1053`	`/* We assume to be passed big endian arguments */`
`1054`		`-#pragma GCC diagnostic push`
`1055`		`-#pragma GCC diagnostic ignored "-Wpragmas"`
`1056`		`-#pragma GCC diagnostic ignored "-Wattribute-alias"`
`1057`	`1054`	`SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs)`
`1058`	`1055`	`{`
`1059`	`1056`	`struct rtas_args args;`
`@@ -1140,7 +1137,6 @@ SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs)`
`1140`	`1137`
`1141`	`1138`	`return 0;`
`1142`	`1139`	`}`
`1143`		`-#pragma GCC diagnostic pop`
`1144`	`1140`
`1145`	`1141`	`/*`
`1146`	`1142`	`* Call early during boot, before mem init, to retrieve the RTAS`
Original file line number	Diff line number	Diff line change
`@@ -62,9 +62,6 @@ static inline long do_mmap2(unsigned long addr, size_t len,`
`62`	`62`	`return ret;`
`63`	`63`	`}`
`64`	`64`
`65`		`-#pragma GCC diagnostic push`
`66`		`-#pragma GCC diagnostic ignored "-Wpragmas"`
`67`		`-#pragma GCC diagnostic ignored "-Wattribute-alias"`
`68`	`65`	`SYSCALL_DEFINE6(mmap2, unsigned long, addr, size_t, len,`
`69`	`66`	`unsigned long, prot, unsigned long, flags,`
`70`	`67`	`unsigned long, fd, unsigned long, pgoff)`
`@@ -78,7 +75,6 @@ SYSCALL_DEFINE6(mmap, unsigned long, addr, size_t, len,`
`78`	`75`	`{`
`79`	`76`	`return do_mmap2(addr, len, prot, flags, fd, offset, PAGE_SHIFT);`
`80`	`77`	`}`
`81`		`-#pragma GCC diagnostic pop`
`82`	`78`
`83`	`79`	`#ifdef CONFIG_PPC32`
`84`	`80`	`/*`
Original file line number	Diff line number	Diff line change
`@@ -186,9 +186,6 @@ static void subpage_mark_vma_nohuge(struct mm_struct *mm, unsigned long addr,`
`186`	`186`	`* in a 2-bit field won't allow writes to a page that is otherwise`
`187`	`187`	`* write-protected.`
`188`	`188`	`*/`
`189`		`-#pragma GCC diagnostic push`
`190`		`-#pragma GCC diagnostic ignored "-Wpragmas"`
`191`		`-#pragma GCC diagnostic ignored "-Wattribute-alias"`
`192`	`189`	`SYSCALL_DEFINE3(subpage_prot, unsigned long, addr,`
`193`	`190`	`unsigned long, len, u32 __user *, map)`
`194`	`191`	`{`
`@@ -272,4 +269,3 @@ SYSCALL_DEFINE3(subpage_prot, unsigned long, addr,`
`272`	`269`	`up_write(&mm->mmap_sem);`
`273`	`270`	`return err;`
`274`	`271`	`}`
`275`		`-#pragma GCC diagnostic pop`