[REVIEW][PATCH 3/6] signal: Remove the need for __ARCH_SI_PREABLE_SIZE and SI_PAD_SIZE
From: Eric W. Biederman
Date: Tue Sep 25 2018 - 13:20:19 EST
Rework the defintion of struct siginfo so that the array padding
struct siginfo to SI_MAX_SIZE can be placed in a union along side of
the rest of the struct siginfo members. The result is that we no
longer need the __ARCH_SI_PREAMBLE_SIZE or SI_PAD_SIZE definitions.
Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
---
arch/alpha/include/uapi/asm/siginfo.h | 1 -
arch/arm64/include/uapi/asm/Kbuild | 1 +
arch/arm64/include/uapi/asm/siginfo.h | 24 ---
arch/ia64/include/uapi/asm/siginfo.h | 2 -
arch/mips/include/uapi/asm/siginfo.h | 11 --
arch/parisc/include/uapi/asm/Kbuild | 1 +
arch/parisc/include/uapi/asm/siginfo.h | 11 --
arch/powerpc/include/uapi/asm/Kbuild | 1 +
arch/powerpc/include/uapi/asm/siginfo.h | 18 ---
arch/riscv/include/uapi/asm/Kbuild | 1 +
arch/riscv/include/uapi/asm/siginfo.h | 24 ---
arch/s390/include/uapi/asm/Kbuild | 1 +
arch/s390/include/uapi/asm/siginfo.h | 17 ---
arch/sparc/include/uapi/asm/siginfo.h | 1 -
arch/x86/include/uapi/asm/siginfo.h | 2 -
include/uapi/asm-generic/siginfo.h | 187 ++++++++++++------------
kernel/signal.c | 3 -
17 files changed, 99 insertions(+), 207 deletions(-)
delete mode 100644 arch/arm64/include/uapi/asm/siginfo.h
delete mode 100644 arch/parisc/include/uapi/asm/siginfo.h
delete mode 100644 arch/powerpc/include/uapi/asm/siginfo.h
delete mode 100644 arch/riscv/include/uapi/asm/siginfo.h
delete mode 100644 arch/s390/include/uapi/asm/siginfo.h
diff --git a/arch/alpha/include/uapi/asm/siginfo.h b/arch/alpha/include/uapi/asm/siginfo.h
index db3f0138536f..6e1a2af2f962 100644
--- a/arch/alpha/include/uapi/asm/siginfo.h
+++ b/arch/alpha/include/uapi/asm/siginfo.h
@@ -2,7 +2,6 @@
#ifndef _ALPHA_SIGINFO_H
#define _ALPHA_SIGINFO_H
-#define __ARCH_SI_PREAMBLE_SIZE (4 * sizeof(int))
#define __ARCH_SI_TRAPNO
#include <asm-generic/siginfo.h>
diff --git a/arch/arm64/include/uapi/asm/Kbuild b/arch/arm64/include/uapi/asm/Kbuild
index 198afbf0688f..6c5adf458690 100644
--- a/arch/arm64/include/uapi/asm/Kbuild
+++ b/arch/arm64/include/uapi/asm/Kbuild
@@ -19,3 +19,4 @@ generic-y += swab.h
generic-y += termbits.h
generic-y += termios.h
generic-y += types.h
+generic-y += siginfo.h
diff --git a/arch/arm64/include/uapi/asm/siginfo.h b/arch/arm64/include/uapi/asm/siginfo.h
deleted file mode 100644
index 574d12f86039..000000000000
--- a/arch/arm64/include/uapi/asm/siginfo.h
+++ /dev/null
@@ -1,24 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-/*
- * Copyright (C) 2012 ARM Ltd.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-#ifndef __ASM_SIGINFO_H
-#define __ASM_SIGINFO_H
-
-#define __ARCH_SI_PREAMBLE_SIZE (4 * sizeof(int))
-
-#include <asm-generic/siginfo.h>
-
-#endif
diff --git a/arch/ia64/include/uapi/asm/siginfo.h b/arch/ia64/include/uapi/asm/siginfo.h
index 52b5af424511..796af1ccaa7e 100644
--- a/arch/ia64/include/uapi/asm/siginfo.h
+++ b/arch/ia64/include/uapi/asm/siginfo.h
@@ -9,8 +9,6 @@
#define _UAPI_ASM_IA64_SIGINFO_H
-#define __ARCH_SI_PREAMBLE_SIZE (4 * sizeof(int))
-
#include <asm-generic/siginfo.h>
#define si_imm _sifields._sigfault._imm /* as per UNIX SysV ABI spec */
diff --git a/arch/mips/include/uapi/asm/siginfo.h b/arch/mips/include/uapi/asm/siginfo.h
index 262504bd59a5..c34c7eef0a1c 100644
--- a/arch/mips/include/uapi/asm/siginfo.h
+++ b/arch/mips/include/uapi/asm/siginfo.h
@@ -14,17 +14,6 @@
#define __ARCH_SIGEV_PREAMBLE_SIZE (sizeof(long) + 2*sizeof(int))
#undef __ARCH_SI_TRAPNO /* exception code needs to fill this ... */
-/*
- * Careful to keep union _sifields from shifting ...
- */
-#if _MIPS_SZLONG == 32
-#define __ARCH_SI_PREAMBLE_SIZE (3 * sizeof(int))
-#elif _MIPS_SZLONG == 64
-#define __ARCH_SI_PREAMBLE_SIZE (4 * sizeof(int))
-#else
-#error _MIPS_SZLONG neither 32 nor 64
-#endif
-
#define __ARCH_HAS_SWAPPED_SIGINFO
#include <asm-generic/siginfo.h>
diff --git a/arch/parisc/include/uapi/asm/Kbuild b/arch/parisc/include/uapi/asm/Kbuild
index 286ef5a5904b..adb5c64831c7 100644
--- a/arch/parisc/include/uapi/asm/Kbuild
+++ b/arch/parisc/include/uapi/asm/Kbuild
@@ -7,3 +7,4 @@ generic-y += kvm_para.h
generic-y += param.h
generic-y += poll.h
generic-y += resource.h
+generic-y += siginfo.h
diff --git a/arch/parisc/include/uapi/asm/siginfo.h b/arch/parisc/include/uapi/asm/siginfo.h
deleted file mode 100644
index 4a1062e05aaf..000000000000
--- a/arch/parisc/include/uapi/asm/siginfo.h
+++ /dev/null
@@ -1,11 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#ifndef _PARISC_SIGINFO_H
-#define _PARISC_SIGINFO_H
-
-#if defined(__LP64__)
-#define __ARCH_SI_PREAMBLE_SIZE (4 * sizeof(int))
-#endif
-
-#include <asm-generic/siginfo.h>
-
-#endif
diff --git a/arch/powerpc/include/uapi/asm/Kbuild b/arch/powerpc/include/uapi/asm/Kbuild
index 1a6ed5919ffd..a658091a19f9 100644
--- a/arch/powerpc/include/uapi/asm/Kbuild
+++ b/arch/powerpc/include/uapi/asm/Kbuild
@@ -7,3 +7,4 @@ generic-y += poll.h
generic-y += resource.h
generic-y += sockios.h
generic-y += statfs.h
+generic-y += siginfo.h
diff --git a/arch/powerpc/include/uapi/asm/siginfo.h b/arch/powerpc/include/uapi/asm/siginfo.h
deleted file mode 100644
index 1d51d9b88221..000000000000
--- a/arch/powerpc/include/uapi/asm/siginfo.h
+++ /dev/null
@@ -1,18 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
-#ifndef _ASM_POWERPC_SIGINFO_H
-#define _ASM_POWERPC_SIGINFO_H
-
-/*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
-
-#ifdef __powerpc64__
-# define __ARCH_SI_PREAMBLE_SIZE (4 * sizeof(int))
-#endif
-
-#include <asm-generic/siginfo.h>
-
-#endif /* _ASM_POWERPC_SIGINFO_H */
diff --git a/arch/riscv/include/uapi/asm/Kbuild b/arch/riscv/include/uapi/asm/Kbuild
index 7e91f4850475..5511b9918131 100644
--- a/arch/riscv/include/uapi/asm/Kbuild
+++ b/arch/riscv/include/uapi/asm/Kbuild
@@ -26,3 +26,4 @@ generic-y += swab.h
generic-y += termbits.h
generic-y += termios.h
generic-y += types.h
+generic-y += siginfo.h
diff --git a/arch/riscv/include/uapi/asm/siginfo.h b/arch/riscv/include/uapi/asm/siginfo.h
deleted file mode 100644
index f96849aac662..000000000000
--- a/arch/riscv/include/uapi/asm/siginfo.h
+++ /dev/null
@@ -1,24 +0,0 @@
-/*
- * Copyright (C) 2012 ARM Ltd.
- * Copyright (C) 2016 SiFive, Inc.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-#ifndef __ASM_SIGINFO_H
-#define __ASM_SIGINFO_H
-
-#define __ARCH_SI_PREAMBLE_SIZE (__SIZEOF_POINTER__ == 4 ? 12 : 16)
-
-#include <asm-generic/siginfo.h>
-
-#endif
diff --git a/arch/s390/include/uapi/asm/Kbuild b/arch/s390/include/uapi/asm/Kbuild
index e364873e0d10..dc38a90cf091 100644
--- a/arch/s390/include/uapi/asm/Kbuild
+++ b/arch/s390/include/uapi/asm/Kbuild
@@ -18,3 +18,4 @@ generic-y += shmbuf.h
generic-y += sockios.h
generic-y += swab.h
generic-y += termbits.h
+generic-y += siginfo.h
\ No newline at end of file
diff --git a/arch/s390/include/uapi/asm/siginfo.h b/arch/s390/include/uapi/asm/siginfo.h
deleted file mode 100644
index 6984820f2f1c..000000000000
--- a/arch/s390/include/uapi/asm/siginfo.h
+++ /dev/null
@@ -1,17 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-/*
- * S390 version
- *
- * Derived from "include/asm-i386/siginfo.h"
- */
-
-#ifndef _S390_SIGINFO_H
-#define _S390_SIGINFO_H
-
-#ifdef __s390x__
-#define __ARCH_SI_PREAMBLE_SIZE (4 * sizeof(int))
-#endif
-
-#include <asm-generic/siginfo.h>
-
-#endif
diff --git a/arch/sparc/include/uapi/asm/siginfo.h b/arch/sparc/include/uapi/asm/siginfo.h
index 6c820ea0813b..68bdde4c2a2e 100644
--- a/arch/sparc/include/uapi/asm/siginfo.h
+++ b/arch/sparc/include/uapi/asm/siginfo.h
@@ -4,7 +4,6 @@
#if defined(__sparc__) && defined(__arch64__)
-#define __ARCH_SI_PREAMBLE_SIZE (4 * sizeof(int))
#define __ARCH_SI_BAND_T int
#endif /* defined(__sparc__) && defined(__arch64__) */
diff --git a/arch/x86/include/uapi/asm/siginfo.h b/arch/x86/include/uapi/asm/siginfo.h
index b3d157957177..6642d8be40c4 100644
--- a/arch/x86/include/uapi/asm/siginfo.h
+++ b/arch/x86/include/uapi/asm/siginfo.h
@@ -7,8 +7,6 @@
typedef long long __kernel_si_clock_t __attribute__((aligned(4)));
# define __ARCH_SI_CLOCK_T __kernel_si_clock_t
# define __ARCH_SI_ATTRIBUTES __attribute__((aligned(8)))
-# else /* x86-64 */
-# define __ARCH_SI_PREAMBLE_SIZE (4 * sizeof(int))
# endif
#endif
diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h
index 1811b8101937..cb3d6c267181 100644
--- a/include/uapi/asm-generic/siginfo.h
+++ b/include/uapi/asm-generic/siginfo.h
@@ -10,18 +10,7 @@ typedef union sigval {
void __user *sival_ptr;
} sigval_t;
-/*
- * This is the size (including padding) of the part of the
- * struct siginfo that is before the union.
- */
-#ifndef __ARCH_SI_PREAMBLE_SIZE
-#define __ARCH_SI_PREAMBLE_SIZE (3 * sizeof(int))
-#endif
-
#define SI_MAX_SIZE 128
-#ifndef SI_PAD_SIZE
-#define SI_PAD_SIZE ((SI_MAX_SIZE - __ARCH_SI_PREAMBLE_SIZE) / sizeof(int))
-#endif
/*
* The default "si_band" type is "long", as specified by POSIX.
@@ -40,96 +29,108 @@ typedef union sigval {
#define __ARCH_SI_ATTRIBUTES
#endif
-typedef struct siginfo {
- int si_signo;
-#ifndef __ARCH_HAS_SWAPPED_SIGINFO
- int si_errno;
- int si_code;
-#else
- int si_code;
- int si_errno;
-#endif
-
- union {
- int _pad[SI_PAD_SIZE];
-
- /* kill() */
- struct {
- __kernel_pid_t _pid; /* sender's pid */
- __kernel_uid32_t _uid; /* sender's uid */
- } _kill;
-
- /* POSIX.1b timers */
- struct {
- __kernel_timer_t _tid; /* timer id */
- int _overrun; /* overrun count */
- sigval_t _sigval; /* same as below */
- int _sys_private; /* not to be passed to user */
- } _timer;
-
- /* POSIX.1b signals */
- struct {
- __kernel_pid_t _pid; /* sender's pid */
- __kernel_uid32_t _uid; /* sender's uid */
- sigval_t _sigval;
- } _rt;
-
- /* SIGCHLD */
- struct {
- __kernel_pid_t _pid; /* which child */
- __kernel_uid32_t _uid; /* sender's uid */
- int _status; /* exit code */
- __ARCH_SI_CLOCK_T _utime;
- __ARCH_SI_CLOCK_T _stime;
- } _sigchld;
-
- /* SIGILL, SIGFPE, SIGSEGV, SIGBUS, SIGTRAP, SIGEMT */
- struct {
- void __user *_addr; /* faulting insn/memory ref. */
+union __sifields {
+ /* kill() */
+ struct {
+ __kernel_pid_t _pid; /* sender's pid */
+ __kernel_uid32_t _uid; /* sender's uid */
+ } _kill;
+
+ /* POSIX.1b timers */
+ struct {
+ __kernel_timer_t _tid; /* timer id */
+ int _overrun; /* overrun count */
+ sigval_t _sigval; /* same as below */
+ int _sys_private; /* not to be passed to user */
+ } _timer;
+
+ /* POSIX.1b signals */
+ struct {
+ __kernel_pid_t _pid; /* sender's pid */
+ __kernel_uid32_t _uid; /* sender's uid */
+ sigval_t _sigval;
+ } _rt;
+
+ /* SIGCHLD */
+ struct {
+ __kernel_pid_t _pid; /* which child */
+ __kernel_uid32_t _uid; /* sender's uid */
+ int _status; /* exit code */
+ __ARCH_SI_CLOCK_T _utime;
+ __ARCH_SI_CLOCK_T _stime;
+ } _sigchld;
+
+ /* SIGILL, SIGFPE, SIGSEGV, SIGBUS, SIGTRAP, SIGEMT */
+ struct {
+ void __user *_addr; /* faulting insn/memory ref. */
#ifdef __ARCH_SI_TRAPNO
- int _trapno; /* TRAP # which caused the signal */
+ int _trapno; /* TRAP # which caused the signal */
#endif
#ifdef __ia64__
- int _imm; /* immediate value for "break" */
- unsigned int _flags; /* see ia64 si_flags */
- unsigned long _isr; /* isr */
+ int _imm; /* immediate value for "break" */
+ unsigned int _flags; /* see ia64 si_flags */
+ unsigned long _isr; /* isr */
#endif
#define __ADDR_BND_PKEY_PAD (__alignof__(void *) < sizeof(short) ? \
sizeof(short) : __alignof__(void *))
- union {
- /*
- * used when si_code=BUS_MCEERR_AR or
- * used when si_code=BUS_MCEERR_AO
- */
- short _addr_lsb; /* LSB of the reported address */
- /* used when si_code=SEGV_BNDERR */
- struct {
- char _dummy_bnd[__ADDR_BND_PKEY_PAD];
- void __user *_lower;
- void __user *_upper;
- } _addr_bnd;
- /* used when si_code=SEGV_PKUERR */
- struct {
- char _dummy_pkey[__ADDR_BND_PKEY_PAD];
- __u32 _pkey;
- } _addr_pkey;
- };
- } _sigfault;
-
- /* SIGPOLL */
- struct {
- __ARCH_SI_BAND_T _band; /* POLL_IN, POLL_OUT, POLL_MSG */
- int _fd;
- } _sigpoll;
+ union {
+ /*
+ * used when si_code=BUS_MCEERR_AR or
+ * used when si_code=BUS_MCEERR_AO
+ */
+ short _addr_lsb; /* LSB of the reported address */
+ /* used when si_code=SEGV_BNDERR */
+ struct {
+ char _dummy_bnd[__ADDR_BND_PKEY_PAD];
+ void __user *_lower;
+ void __user *_upper;
+ } _addr_bnd;
+ /* used when si_code=SEGV_PKUERR */
+ struct {
+ char _dummy_pkey[__ADDR_BND_PKEY_PAD];
+ __u32 _pkey;
+ } _addr_pkey;
+ };
+ } _sigfault;
+
+ /* SIGPOLL */
+ struct {
+ __ARCH_SI_BAND_T _band; /* POLL_IN, POLL_OUT, POLL_MSG */
+ int _fd;
+ } _sigpoll;
+
+ /* SIGSYS */
+ struct {
+ void __user *_call_addr; /* calling user insn */
+ int _syscall; /* triggering system call number */
+ unsigned int _arch; /* AUDIT_ARCH_* of syscall */
+ } _sigsys;
+};
- /* SIGSYS */
- struct {
- void __user *_call_addr; /* calling user insn */
- int _syscall; /* triggering system call number */
- unsigned int _arch; /* AUDIT_ARCH_* of syscall */
- } _sigsys;
- } _sifields;
+#ifndef __ARCH_HAS_SWAPPED_SIGINFO
+#define __SIGINFO \
+struct { \
+ int si_signo; \
+ int si_errno; \
+ int si_code; \
+ union __sifields _sifields; \
+}
+#else
+#define __SIGINFO \
+struct { \
+ int si_signo; \
+ int si_code; \
+ int si_errno; \
+ union __sifields _sifields; \
+}
+#endif /* __ARCH_HAS_SWAPPED_SIGINFO */
+
+typedef struct siginfo {
+ union {
+ __SIGINFO;
+ int _si_pad[SI_MAX_SIZE/sizeof(int)];
+ };
} __ARCH_SI_ATTRIBUTES siginfo_t;
/*
diff --git a/kernel/signal.c b/kernel/signal.c
index e445b0a63faa..debb485a76db 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3963,9 +3963,6 @@ __weak const char *arch_vma_name(struct vm_area_struct *vma)
void __init signals_init(void)
{
- /* If this check fails, the __ARCH_SI_PREAMBLE_SIZE value is wrong! */
- BUILD_BUG_ON(__ARCH_SI_PREAMBLE_SIZE
- != offsetof(struct siginfo, _sifields._pad));
BUILD_BUG_ON(sizeof(struct siginfo) != SI_MAX_SIZE);
sigqueue_cachep = KMEM_CACHE(sigqueue, SLAB_PANIC);
--
2.17.1