[PATCH 1/2] x86/signal: Move siginfo field tests
From: Brian Gerst
Date: Mon Dec 19 2022 - 14:39:44 EST
Move the tests to the appropriate signal_$(BITS).c file.
Convert them to use static_assert(), removing the need for a dummy
function.
Signed-off-by: Brian Gerst <brgerst@xxxxxxxxx>
---
arch/x86/kernel/signal_32.c | 127 +++++++++++++++++++++++
arch/x86/kernel/signal_64.c | 114 +++++++++++++++++++++
arch/x86/kernel/signal_compat.c | 176 --------------------------------
3 files changed, 241 insertions(+), 176 deletions(-)
diff --git a/arch/x86/kernel/signal_32.c b/arch/x86/kernel/signal_32.c
index 2553136cf39b..f042dcdf1f16 100644
--- a/arch/x86/kernel/signal_32.c
+++ b/arch/x86/kernel/signal_32.c
@@ -54,12 +54,14 @@ static inline void reload_segments(struct sigcontext_32 *sc)
}
#define sigset32_t compat_sigset_t
+#define siginfo32_t compat_siginfo_t
#define restore_altstack32 compat_restore_altstack
#define unsafe_save_altstack32 unsafe_compat_save_altstack
#else
#define sigset32_t sigset_t
+#define siginfo32_t siginfo_t
#define __NR_ia32_sigreturn __NR_sigreturn
#define __NR_ia32_rt_sigreturn __NR_rt_sigreturn
#define restore_altstack32 restore_altstack
@@ -377,3 +379,128 @@ int ia32_setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
user_access_end();
return -EFAULT;
}
+
+/*
+ * The siginfo_t structure and handing code is very easy
+ * to break in several ways. It must always be updated when new
+ * updates are made to the main siginfo_t, and
+ * copy_siginfo_to_user32() must be updated when the
+ * (arch-independent) copy_siginfo_to_user() is updated.
+ *
+ * It is also easy to put a new member in the siginfo_t
+ * which has implicit alignment which can move internal structure
+ * alignment around breaking the ABI. This can happen if you,
+ * for instance, put a plain 64-bit value in there.
+ */
+
+/*
+* If adding a new si_code, there is probably new data in
+* the siginfo. Make sure folks bumping the si_code
+* limits also have to look at this code. Make sure any
+* new fields are handled in copy_siginfo_to_user32()!
+*/
+static_assert(NSIGILL == 11);
+static_assert(NSIGFPE == 15);
+static_assert(NSIGSEGV == 9);
+static_assert(NSIGBUS == 5);
+static_assert(NSIGTRAP == 6);
+static_assert(NSIGCHLD == 6);
+static_assert(NSIGSYS == 2);
+
+/* This is part of the ABI and can never change in size: */
+static_assert(sizeof(siginfo32_t) == 128);
+
+/* This is a part of the ABI and can never change in alignment */
+static_assert(__alignof__(siginfo32_t) == 4);
+
+/*
+* The offsets of all the (unioned) si_fields are fixed
+* in the ABI, of course. Make sure none of them ever
+* move and are always at the beginning:
+*/
+static_assert(offsetof(siginfo32_t, _sifields) == 3 * sizeof(int));
+
+static_assert(offsetof(siginfo32_t, si_signo) == 0);
+static_assert(offsetof(siginfo32_t, si_errno) == 4);
+static_assert(offsetof(siginfo32_t, si_code) == 8);
+
+/*
+* Ensure that the size of each si_field never changes.
+* If it does, it is a sign that the
+* copy_siginfo_to_user32() code below needs to updated
+* along with the size in the CHECK_SI_SIZE().
+*
+* We repeat this check for both the generic and compat
+* siginfos.
+*
+* Note: it is OK for these to grow as long as the whole
+* structure stays within the padding size (checked
+* above).
+*/
+
+#define CHECK_SI_OFFSET(name) \
+ static_assert(offsetof(siginfo32_t, _sifields) == \
+ offsetof(siginfo32_t, _sifields.name))
+
+#define CHECK_SI_SIZE(name, size) \
+ static_assert(sizeof_field(siginfo32_t, _sifields.name) == size)
+
+CHECK_SI_OFFSET(_kill);
+CHECK_SI_SIZE (_kill, 2*sizeof(int));
+static_assert(offsetof(siginfo32_t, si_pid) == 0xC);
+static_assert(offsetof(siginfo32_t, si_uid) == 0x10);
+
+CHECK_SI_OFFSET(_timer);
+#ifdef CONFIG_COMPAT
+/* compat_siginfo_t doesn't have si_sys_private */
+CHECK_SI_SIZE (_timer, 3*sizeof(int));
+#else
+CHECK_SI_SIZE (_timer, 4*sizeof(int));
+#endif
+static_assert(offsetof(siginfo32_t, si_tid) == 0x0C);
+static_assert(offsetof(siginfo32_t, si_overrun) == 0x10);
+static_assert(offsetof(siginfo32_t, si_value) == 0x14);
+
+CHECK_SI_OFFSET(_rt);
+CHECK_SI_SIZE (_rt, 3*sizeof(int));
+static_assert(offsetof(siginfo32_t, si_pid) == 0x0C);
+static_assert(offsetof(siginfo32_t, si_uid) == 0x10);
+static_assert(offsetof(siginfo32_t, si_value) == 0x14);
+
+CHECK_SI_OFFSET(_sigchld);
+CHECK_SI_SIZE (_sigchld, 5*sizeof(int));
+static_assert(offsetof(siginfo32_t, si_pid) == 0x0C);
+static_assert(offsetof(siginfo32_t, si_uid) == 0x10);
+static_assert(offsetof(siginfo32_t, si_status) == 0x14);
+static_assert(offsetof(siginfo32_t, si_utime) == 0x18);
+static_assert(offsetof(siginfo32_t, si_stime) == 0x1C);
+
+CHECK_SI_OFFSET(_sigfault);
+CHECK_SI_SIZE (_sigfault, 4*sizeof(int));
+static_assert(offsetof(siginfo32_t, si_addr) == 0x0C);
+
+static_assert(offsetof(siginfo32_t, si_trapno) == 0x10);
+
+static_assert(offsetof(siginfo32_t, si_addr_lsb) == 0x10);
+
+static_assert(offsetof(siginfo32_t, si_lower) == 0x14);
+static_assert(offsetof(siginfo32_t, si_upper) == 0x18);
+
+static_assert(offsetof(siginfo32_t, si_pkey) == 0x14);
+
+static_assert(offsetof(siginfo32_t, si_perf_data) == 0x10);
+static_assert(offsetof(siginfo32_t, si_perf_type) == 0x14);
+static_assert(offsetof(siginfo32_t, si_perf_flags) == 0x18);
+
+CHECK_SI_OFFSET(_sigpoll);
+CHECK_SI_SIZE (_sigpoll, 2*sizeof(int));
+static_assert(offsetof(siginfo32_t, si_band) == 0x0C);
+static_assert(offsetof(siginfo32_t, si_fd) == 0x10);
+
+CHECK_SI_OFFSET(_sigsys);
+CHECK_SI_SIZE (_sigsys, 3*sizeof(int));
+static_assert(offsetof(siginfo32_t, si_call_addr) == 0x0C);
+static_assert(offsetof(siginfo32_t, si_syscall) == 0x10);
+static_assert(offsetof(siginfo32_t, si_arch) == 0x14);
+
+/* any new si_fields should be added here */
diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
index ff9c55064223..9eea4e8f12ee 100644
--- a/arch/x86/kernel/signal_64.c
+++ b/arch/x86/kernel/signal_64.c
@@ -381,3 +381,117 @@ COMPAT_SYSCALL_DEFINE0(x32_rt_sigreturn)
return 0;
}
#endif /* CONFIG_X86_X32_ABI */
+
+/*
+* If adding a new si_code, there is probably new data in
+* the siginfo. Make sure folks bumping the si_code
+* limits also have to look at this code. Make sure any
+* new fields are handled in copy_siginfo_to_user32()!
+*/
+static_assert(NSIGILL == 11);
+static_assert(NSIGFPE == 15);
+static_assert(NSIGSEGV == 9);
+static_assert(NSIGBUS == 5);
+static_assert(NSIGTRAP == 6);
+static_assert(NSIGCHLD == 6);
+static_assert(NSIGSYS == 2);
+
+/* This is part of the ABI and can never change in size: */
+static_assert(sizeof(siginfo_t) == 128);
+
+/* This is a part of the ABI and can never change in alignment */
+static_assert(__alignof__(siginfo_t) == 8);
+
+/*
+* The offsets of all the (unioned) si_fields are fixed
+* in the ABI, of course. Make sure none of them ever
+* move and are always at the beginning:
+*/
+static_assert(offsetof(siginfo_t, si_signo) == 0);
+static_assert(offsetof(siginfo_t, si_errno) == 4);
+static_assert(offsetof(siginfo_t, si_code) == 8);
+
+/*
+* Ensure that the size of each si_field never changes.
+* If it does, it is a sign that the
+* copy_siginfo_to_user32() code below needs to updated
+* along with the size in the CHECK_SI_SIZE().
+*
+* We repeat this check for both the generic and compat
+* siginfos.
+*
+* Note: it is OK for these to grow as long as the whole
+* structure stays within the padding size (checked
+* above).
+*/
+
+#define CHECK_SI_OFFSET(name) \
+ static_assert(offsetof(siginfo_t, _sifields) == \
+ offsetof(siginfo_t, _sifields.name))
+#define CHECK_SI_SIZE(name, size) \
+ static_assert(sizeof_field(siginfo_t, _sifields.name) == size)
+
+CHECK_SI_OFFSET(_kill);
+CHECK_SI_SIZE (_kill, 2*sizeof(int));
+static_assert(offsetof(siginfo_t, si_pid) == 0x10);
+static_assert(offsetof(siginfo_t, si_uid) == 0x14);
+
+CHECK_SI_OFFSET(_timer);
+CHECK_SI_SIZE (_timer, 6*sizeof(int));
+static_assert(offsetof(siginfo_t, si_tid) == 0x10);
+static_assert(offsetof(siginfo_t, si_overrun) == 0x14);
+static_assert(offsetof(siginfo_t, si_value) == 0x18);
+
+CHECK_SI_OFFSET(_rt);
+CHECK_SI_SIZE (_rt, 4*sizeof(int));
+static_assert(offsetof(siginfo_t, si_pid) == 0x10);
+static_assert(offsetof(siginfo_t, si_uid) == 0x14);
+static_assert(offsetof(siginfo_t, si_value) == 0x18);
+
+CHECK_SI_OFFSET(_sigchld);
+CHECK_SI_SIZE (_sigchld, 8*sizeof(int));
+static_assert(offsetof(siginfo_t, si_pid) == 0x10);
+static_assert(offsetof(siginfo_t, si_uid) == 0x14);
+static_assert(offsetof(siginfo_t, si_status) == 0x18);
+static_assert(offsetof(siginfo_t, si_utime) == 0x20);
+static_assert(offsetof(siginfo_t, si_stime) == 0x28);
+
+#ifdef CONFIG_X86_X32_ABI
+/* no _sigchld_x32 in the generic siginfo_t */
+static_assert(sizeof_field(compat_siginfo_t, _sifields._sigchld_x32) ==
+ 7*sizeof(int));
+static_assert(offsetof(compat_siginfo_t, _sifields) ==
+ offsetof(compat_siginfo_t, _sifields._sigchld_x32));
+static_assert(offsetof(compat_siginfo_t, _sifields._sigchld_x32._utime) == 0x18);
+static_assert(offsetof(compat_siginfo_t, _sifields._sigchld_x32._stime) == 0x20);
+#endif
+
+CHECK_SI_OFFSET(_sigfault);
+CHECK_SI_SIZE (_sigfault, 8*sizeof(int));
+static_assert(offsetof(siginfo_t, si_addr) == 0x10);
+
+static_assert(offsetof(siginfo_t, si_trapno) == 0x18);
+
+static_assert(offsetof(siginfo_t, si_addr_lsb) == 0x18);
+
+static_assert(offsetof(siginfo_t, si_lower) == 0x20);
+static_assert(offsetof(siginfo_t, si_upper) == 0x28);
+
+static_assert(offsetof(siginfo_t, si_pkey) == 0x20);
+
+static_assert(offsetof(siginfo_t, si_perf_data) == 0x18);
+static_assert(offsetof(siginfo_t, si_perf_type) == 0x20);
+static_assert(offsetof(siginfo_t, si_perf_flags) == 0x24);
+
+CHECK_SI_OFFSET(_sigpoll);
+CHECK_SI_SIZE (_sigpoll, 4*sizeof(int));
+static_assert(offsetof(siginfo_t, si_band) == 0x10);
+static_assert(offsetof(siginfo_t, si_fd) == 0x18);
+
+CHECK_SI_OFFSET(_sigsys);
+CHECK_SI_SIZE (_sigsys, 4*sizeof(int));
+static_assert(offsetof(siginfo_t, si_call_addr) == 0x10);
+static_assert(offsetof(siginfo_t, si_syscall) == 0x18);
+static_assert(offsetof(siginfo_t, si_arch) == 0x1C);
+
+/* any new si_fields should be added here */
diff --git a/arch/x86/kernel/signal_compat.c b/arch/x86/kernel/signal_compat.c
index 879ef8c72f5c..c4e9b85f1869 100644
--- a/arch/x86/kernel/signal_compat.c
+++ b/arch/x86/kernel/signal_compat.c
@@ -3,184 +3,8 @@
#include <linux/uaccess.h>
#include <linux/ptrace.h>
-/*
- * The compat_siginfo_t structure and handing code is very easy
- * to break in several ways. It must always be updated when new
- * updates are made to the main siginfo_t, and
- * copy_siginfo_to_user32() must be updated when the
- * (arch-independent) copy_siginfo_to_user() is updated.
- *
- * It is also easy to put a new member in the compat_siginfo_t
- * which has implicit alignment which can move internal structure
- * alignment around breaking the ABI. This can happen if you,
- * for instance, put a plain 64-bit value in there.
- */
-static inline void signal_compat_build_tests(void)
-{
- int _sifields_offset = offsetof(compat_siginfo_t, _sifields);
-
- /*
- * If adding a new si_code, there is probably new data in
- * the siginfo. Make sure folks bumping the si_code
- * limits also have to look at this code. Make sure any
- * new fields are handled in copy_siginfo_to_user32()!
- */
- BUILD_BUG_ON(NSIGILL != 11);
- BUILD_BUG_ON(NSIGFPE != 15);
- BUILD_BUG_ON(NSIGSEGV != 9);
- BUILD_BUG_ON(NSIGBUS != 5);
- BUILD_BUG_ON(NSIGTRAP != 6);
- BUILD_BUG_ON(NSIGCHLD != 6);
- BUILD_BUG_ON(NSIGSYS != 2);
-
- /* This is part of the ABI and can never change in size: */
- BUILD_BUG_ON(sizeof(siginfo_t) != 128);
- BUILD_BUG_ON(sizeof(compat_siginfo_t) != 128);
-
- /* This is a part of the ABI and can never change in alignment */
- BUILD_BUG_ON(__alignof__(siginfo_t) != 8);
- BUILD_BUG_ON(__alignof__(compat_siginfo_t) != 4);
-
- /*
- * The offsets of all the (unioned) si_fields are fixed
- * in the ABI, of course. Make sure none of them ever
- * move and are always at the beginning:
- */
- BUILD_BUG_ON(offsetof(compat_siginfo_t, _sifields) != 3 * sizeof(int));
-#define CHECK_CSI_OFFSET(name) BUILD_BUG_ON(_sifields_offset != offsetof(compat_siginfo_t, _sifields.name))
-
- BUILD_BUG_ON(offsetof(siginfo_t, si_signo) != 0);
- BUILD_BUG_ON(offsetof(siginfo_t, si_errno) != 4);
- BUILD_BUG_ON(offsetof(siginfo_t, si_code) != 8);
-
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_signo) != 0);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_errno) != 4);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_code) != 8);
- /*
- * Ensure that the size of each si_field never changes.
- * If it does, it is a sign that the
- * copy_siginfo_to_user32() code below needs to updated
- * along with the size in the CHECK_SI_SIZE().
- *
- * We repeat this check for both the generic and compat
- * siginfos.
- *
- * Note: it is OK for these to grow as long as the whole
- * structure stays within the padding size (checked
- * above).
- */
-#define CHECK_CSI_SIZE(name, size) BUILD_BUG_ON(size != sizeof(((compat_siginfo_t *)0)->_sifields.name))
-#define CHECK_SI_SIZE(name, size) BUILD_BUG_ON(size != sizeof(((siginfo_t *)0)->_sifields.name))
-
- CHECK_CSI_OFFSET(_kill);
- CHECK_CSI_SIZE (_kill, 2*sizeof(int));
- CHECK_SI_SIZE (_kill, 2*sizeof(int));
-
- BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x10);
- BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x14);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pid) != 0xC);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_uid) != 0x10);
-
- CHECK_CSI_OFFSET(_timer);
- CHECK_CSI_SIZE (_timer, 3*sizeof(int));
- CHECK_SI_SIZE (_timer, 6*sizeof(int));
-
- BUILD_BUG_ON(offsetof(siginfo_t, si_tid) != 0x10);
- BUILD_BUG_ON(offsetof(siginfo_t, si_overrun) != 0x14);
- BUILD_BUG_ON(offsetof(siginfo_t, si_value) != 0x18);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_tid) != 0x0C);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_overrun) != 0x10);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_value) != 0x14);
-
- CHECK_CSI_OFFSET(_rt);
- CHECK_CSI_SIZE (_rt, 3*sizeof(int));
- CHECK_SI_SIZE (_rt, 4*sizeof(int));
-
- BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x10);
- BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x14);
- BUILD_BUG_ON(offsetof(siginfo_t, si_value) != 0x18);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pid) != 0x0C);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_uid) != 0x10);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_value) != 0x14);
-
- CHECK_CSI_OFFSET(_sigchld);
- CHECK_CSI_SIZE (_sigchld, 5*sizeof(int));
- CHECK_SI_SIZE (_sigchld, 8*sizeof(int));
-
- BUILD_BUG_ON(offsetof(siginfo_t, si_pid) != 0x10);
- BUILD_BUG_ON(offsetof(siginfo_t, si_uid) != 0x14);
- BUILD_BUG_ON(offsetof(siginfo_t, si_status) != 0x18);
- BUILD_BUG_ON(offsetof(siginfo_t, si_utime) != 0x20);
- BUILD_BUG_ON(offsetof(siginfo_t, si_stime) != 0x28);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pid) != 0x0C);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_uid) != 0x10);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_status) != 0x14);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_utime) != 0x18);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_stime) != 0x1C);
-
-#ifdef CONFIG_X86_X32_ABI
- CHECK_CSI_OFFSET(_sigchld_x32);
- CHECK_CSI_SIZE (_sigchld_x32, 7*sizeof(int));
- /* no _sigchld_x32 in the generic siginfo_t */
- BUILD_BUG_ON(offsetof(compat_siginfo_t, _sifields._sigchld_x32._utime) != 0x18);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, _sifields._sigchld_x32._stime) != 0x20);
-#endif
-
- CHECK_CSI_OFFSET(_sigfault);
- CHECK_CSI_SIZE (_sigfault, 4*sizeof(int));
- CHECK_SI_SIZE (_sigfault, 8*sizeof(int));
-
- BUILD_BUG_ON(offsetof(siginfo_t, si_addr) != 0x10);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_addr) != 0x0C);
-
- BUILD_BUG_ON(offsetof(siginfo_t, si_trapno) != 0x18);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_trapno) != 0x10);
-
- BUILD_BUG_ON(offsetof(siginfo_t, si_addr_lsb) != 0x18);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_addr_lsb) != 0x10);
-
- BUILD_BUG_ON(offsetof(siginfo_t, si_lower) != 0x20);
- BUILD_BUG_ON(offsetof(siginfo_t, si_upper) != 0x28);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_lower) != 0x14);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_upper) != 0x18);
-
- BUILD_BUG_ON(offsetof(siginfo_t, si_pkey) != 0x20);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_pkey) != 0x14);
-
- BUILD_BUG_ON(offsetof(siginfo_t, si_perf_data) != 0x18);
- BUILD_BUG_ON(offsetof(siginfo_t, si_perf_type) != 0x20);
- BUILD_BUG_ON(offsetof(siginfo_t, si_perf_flags) != 0x24);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_perf_data) != 0x10);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_perf_type) != 0x14);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_perf_flags) != 0x18);
-
- CHECK_CSI_OFFSET(_sigpoll);
- CHECK_CSI_SIZE (_sigpoll, 2*sizeof(int));
- CHECK_SI_SIZE (_sigpoll, 4*sizeof(int));
-
- BUILD_BUG_ON(offsetof(siginfo_t, si_band) != 0x10);
- BUILD_BUG_ON(offsetof(siginfo_t, si_fd) != 0x18);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_band) != 0x0C);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_fd) != 0x10);
-
- CHECK_CSI_OFFSET(_sigsys);
- CHECK_CSI_SIZE (_sigsys, 3*sizeof(int));
- CHECK_SI_SIZE (_sigsys, 4*sizeof(int));
-
- BUILD_BUG_ON(offsetof(siginfo_t, si_call_addr) != 0x10);
- BUILD_BUG_ON(offsetof(siginfo_t, si_syscall) != 0x18);
- BUILD_BUG_ON(offsetof(siginfo_t, si_arch) != 0x1C);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_call_addr) != 0x0C);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_syscall) != 0x10);
- BUILD_BUG_ON(offsetof(compat_siginfo_t, si_arch) != 0x14);
-
- /* any new si_fields should be added here */
-}
-
void sigaction_compat_abi(struct k_sigaction *act, struct k_sigaction *oact)
{
- signal_compat_build_tests();
-
if (!act)
return;
--
2.38.1