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From: Peter Collingbourne <pcc@google.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
	Evgenii Stepanov <eugenis@google.com>,
	Kostya Serebryany <kcc@google.com>,
	Vincenzo Frascino <vincenzo.frascino@arm.com>,
	Dave Martin <Dave.Martin@arm.com>, Will Deacon <will@kernel.org>,
	Oleg Nesterov <oleg@redhat.com>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	"James E.J. Bottomley" <James.Bottomley@hansenpartnership.com>
Cc: Peter Collingbourne <pcc@google.com>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	Kevin Brodsky <kevin.brodsky@arm.com>,
	Andrey Konovalov <andreyknvl@google.com>,
	Richard Henderson <rth@twiddle.net>,
	linux-api@vger.kernel.org, Helge Deller <deller@gmx.de>,
	David Spickett <david.spickett@linaro.org>
Subject: [PATCH v12 6/8] signal: deduplicate code dealing with common _sigfault fields
Date: Fri, 16 Oct 2020 17:12:31 -0700	[thread overview]
Message-ID: <3cabc4cf8ac3c7c9005df489625d26193c0db4c7.1602892799.git.pcc@google.com> (raw)
In-Reply-To: <cover.1602892799.git.pcc@google.com>

We're about to add more common _sigfault fields, so deduplicate the
existing code for initializing _sigfault fields in {send,force}_sig_*,
and for copying _sigfault fields in copy_siginfo_to_external32 and
post_copy_siginfo_from_user32, to reduce the number of places that
will need to be updated by upcoming changes.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Link: https://linux-review.googlesource.com/id/I4f56174e1b7b2bf4a3c8139e6879cbfd52750a24
---
 include/linux/signal.h |  13 ++++++
 kernel/signal.c        | 101 ++++++++++++++++-------------------------
 2 files changed, 53 insertions(+), 61 deletions(-)

diff --git a/include/linux/signal.h b/include/linux/signal.h
index 7bbc0e9cf084..9b7fef0c559d 100644
--- a/include/linux/signal.h
+++ b/include/linux/signal.h
@@ -50,6 +50,19 @@ enum siginfo_layout {
 
 enum siginfo_layout siginfo_layout(unsigned sig, int si_code);
 
+static inline bool siginfo_layout_is_fault(enum siginfo_layout layout)
+{
+	switch (layout) {
+	case SIL_FAULT:
+	case SIL_FAULT_MCEERR:
+	case SIL_FAULT_BNDERR:
+	case SIL_FAULT_PKUERR:
+		return true;
+	default:
+		return false;
+	}
+}
+
 /*
  * Define some primitives to manipulate sigset_t.
  */
diff --git a/kernel/signal.c b/kernel/signal.c
index 018c19f6cf66..acdfd5a6d424 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1649,6 +1649,15 @@ void force_sigsegv(int sig)
 	force_sig(SIGSEGV);
 }
 
+static void set_sigfault_common_fields(struct kernel_siginfo *info, int sig,
+				       int code, void __user *addr)
+{
+	info->si_signo = sig;
+	info->si_errno = 0;
+	info->si_code = code;
+	info->si_addr = addr;
+}
+
 int force_sig_fault_to_task(int sig, int code, void __user *addr
 	___ARCH_SI_TRAPNO(int trapno)
 	___ARCH_SI_IA64(int imm, unsigned int flags, unsigned long isr)
@@ -1657,10 +1666,7 @@ int force_sig_fault_to_task(int sig, int code, void __user *addr
 	struct kernel_siginfo info;
 
 	clear_siginfo(&info);
-	info.si_signo = sig;
-	info.si_errno = 0;
-	info.si_code  = code;
-	info.si_addr  = addr;
+	set_sigfault_common_fields(&info, sig, code, addr);
 #ifdef __ARCH_SI_TRAPNO
 	info.si_trapno = trapno;
 #endif
@@ -1689,10 +1695,7 @@ int send_sig_fault(int sig, int code, void __user *addr
 	struct kernel_siginfo info;
 
 	clear_siginfo(&info);
-	info.si_signo = sig;
-	info.si_errno = 0;
-	info.si_code  = code;
-	info.si_addr  = addr;
+	set_sigfault_common_fields(&info, sig, code, addr);
 #ifdef __ARCH_SI_TRAPNO
 	info.si_trapno = trapno;
 #endif
@@ -1710,10 +1713,7 @@ int force_sig_mceerr(int code, void __user *addr, short lsb)
 
 	WARN_ON((code != BUS_MCEERR_AO) && (code != BUS_MCEERR_AR));
 	clear_siginfo(&info);
-	info.si_signo = SIGBUS;
-	info.si_errno = 0;
-	info.si_code = code;
-	info.si_addr = addr;
+	set_sigfault_common_fields(&info, SIGBUS, code, addr);
 	info.si_addr_lsb = lsb;
 	return force_sig_info(&info);
 }
@@ -1724,10 +1724,7 @@ int send_sig_mceerr(int code, void __user *addr, short lsb, struct task_struct *
 
 	WARN_ON((code != BUS_MCEERR_AO) && (code != BUS_MCEERR_AR));
 	clear_siginfo(&info);
-	info.si_signo = SIGBUS;
-	info.si_errno = 0;
-	info.si_code = code;
-	info.si_addr = addr;
+	set_sigfault_common_fields(&info, SIGBUS, code, addr);
 	info.si_addr_lsb = lsb;
 	return send_sig_info(info.si_signo, &info, t);
 }
@@ -1738,10 +1735,7 @@ int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper)
 	struct kernel_siginfo info;
 
 	clear_siginfo(&info);
-	info.si_signo = SIGSEGV;
-	info.si_errno = 0;
-	info.si_code  = SEGV_BNDERR;
-	info.si_addr  = addr;
+	set_sigfault_common_fields(&info, SIGSEGV, SEGV_BNDERR, addr);
 	info.si_lower = lower;
 	info.si_upper = upper;
 	return force_sig_info(&info);
@@ -1753,10 +1747,7 @@ int force_sig_pkuerr(void __user *addr, u32 pkey)
 	struct kernel_siginfo info;
 
 	clear_siginfo(&info);
-	info.si_signo = SIGSEGV;
-	info.si_errno = 0;
-	info.si_code  = SEGV_PKUERR;
-	info.si_addr  = addr;
+	set_sigfault_common_fields(&info, SIGSEGV, SEGV_PKUERR, addr);
 	info.si_pkey  = pkey;
 	return force_sig_info(&info);
 }
@@ -1770,10 +1761,8 @@ int force_sig_ptrace_errno_trap(int errno, void __user *addr)
 	struct kernel_siginfo info;
 
 	clear_siginfo(&info);
-	info.si_signo = SIGTRAP;
+	set_sigfault_common_fields(&info, SIGTRAP, TRAP_HWBKPT, addr);
 	info.si_errno = errno;
-	info.si_code  = TRAP_HWBKPT;
-	info.si_addr  = addr;
 	return force_sig_info(&info);
 }
 
@@ -3266,12 +3255,23 @@ int copy_siginfo_from_user(kernel_siginfo_t *to, const siginfo_t __user *from)
 void copy_siginfo_to_external32(struct compat_siginfo *to,
 		const struct kernel_siginfo *from)
 {
+	enum siginfo_layout layout =
+		siginfo_layout(from->si_signo, from->si_code);
+
 	memset(to, 0, sizeof(*to));
 
 	to->si_signo = from->si_signo;
 	to->si_errno = from->si_errno;
 	to->si_code  = from->si_code;
-	switch(siginfo_layout(from->si_signo, from->si_code)) {
+
+	if (siginfo_layout_is_fault(layout)) {
+		to->si_addr = ptr_to_compat(from->si_addr);
+#ifdef __ARCH_SI_TRAPNO
+		to->si_trapno = from->si_trapno;
+#endif
+	}
+
+	switch (layout) {
 	case SIL_KILL:
 		to->si_pid = from->si_pid;
 		to->si_uid = from->si_uid;
@@ -3286,31 +3286,15 @@ void copy_siginfo_to_external32(struct compat_siginfo *to,
 		to->si_fd   = from->si_fd;
 		break;
 	case SIL_FAULT:
-		to->si_addr = ptr_to_compat(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
-		to->si_trapno = from->si_trapno;
-#endif
 		break;
 	case SIL_FAULT_MCEERR:
-		to->si_addr = ptr_to_compat(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
-		to->si_trapno = from->si_trapno;
-#endif
 		to->si_addr_lsb = from->si_addr_lsb;
 		break;
 	case SIL_FAULT_BNDERR:
-		to->si_addr = ptr_to_compat(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
-		to->si_trapno = from->si_trapno;
-#endif
 		to->si_lower = ptr_to_compat(from->si_lower);
 		to->si_upper = ptr_to_compat(from->si_upper);
 		break;
 	case SIL_FAULT_PKUERR:
-		to->si_addr = ptr_to_compat(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
-		to->si_trapno = from->si_trapno;
-#endif
 		to->si_pkey = from->si_pkey;
 		break;
 	case SIL_CHLD:
@@ -3347,11 +3331,22 @@ int __copy_siginfo_to_user32(struct compat_siginfo __user *to,
 static int post_copy_siginfo_from_user32(kernel_siginfo_t *to,
 					 const struct compat_siginfo *from)
 {
+	enum siginfo_layout layout =
+		siginfo_layout(from->si_signo, from->si_code);
+
 	clear_siginfo(to);
 	to->si_signo = from->si_signo;
 	to->si_errno = from->si_errno;
 	to->si_code  = from->si_code;
-	switch(siginfo_layout(from->si_signo, from->si_code)) {
+
+	if (siginfo_layout_is_fault(layout)) {
+		to->si_addr = compat_ptr(from->si_addr);
+#ifdef __ARCH_SI_TRAPNO
+		to->si_trapno = from->si_trapno;
+#endif
+	}
+
+	switch (layout) {
 	case SIL_KILL:
 		to->si_pid = from->si_pid;
 		to->si_uid = from->si_uid;
@@ -3366,31 +3361,15 @@ static int post_copy_siginfo_from_user32(kernel_siginfo_t *to,
 		to->si_fd   = from->si_fd;
 		break;
 	case SIL_FAULT:
-		to->si_addr = compat_ptr(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
-		to->si_trapno = from->si_trapno;
-#endif
 		break;
 	case SIL_FAULT_MCEERR:
-		to->si_addr = compat_ptr(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
-		to->si_trapno = from->si_trapno;
-#endif
 		to->si_addr_lsb = from->si_addr_lsb;
 		break;
 	case SIL_FAULT_BNDERR:
-		to->si_addr = compat_ptr(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
-		to->si_trapno = from->si_trapno;
-#endif
 		to->si_lower = compat_ptr(from->si_lower);
 		to->si_upper = compat_ptr(from->si_upper);
 		break;
 	case SIL_FAULT_PKUERR:
-		to->si_addr = compat_ptr(from->si_addr);
-#ifdef __ARCH_SI_TRAPNO
-		to->si_trapno = from->si_trapno;
-#endif
 		to->si_pkey = from->si_pkey;
 		break;
 	case SIL_CHLD:
-- 
2.29.0.rc1.297.gfa9743e501-goog


  parent reply	other threads:[~2020-10-17  6:02 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-17  0:12 [PATCH v12 0/8] arm64: expose FAR_EL1 tag bits in siginfo Peter Collingbourne
2020-10-17  0:12 ` [PATCH v12 1/8] parisc: Drop parisc special case for __sighandler_t Peter Collingbourne
2020-10-17  0:12 ` [PATCH v12 2/8] parisc: start using signal-defs.h Peter Collingbourne
2020-10-17  0:12 ` [PATCH v12 3/8] arch: move SA_* definitions to generic headers Peter Collingbourne
2020-11-02 17:23   ` Dave Martin
2020-10-17  0:12 ` [PATCH v12 4/8] signal: clear non-uapi flag bits when passing/returning sa_flags Peter Collingbourne
2020-11-02 17:26   ` Dave Martin
2020-10-17  0:12 ` [PATCH v12 5/8] signal: define the SA_UNSUPPORTED bit in sa_flags Peter Collingbourne
2020-10-17  0:12 ` Peter Collingbourne [this message]
2020-10-17  0:12 ` [PATCH v12 7/8] signal: define the field siginfo.si_xflags Peter Collingbourne
2020-11-02 17:37   ` Dave Martin
2020-11-03  4:10     ` Peter Collingbourne
2020-11-03 11:44       ` Dave Martin
2020-10-17  0:12 ` [PATCH v12 8/8] arm64: expose FAR_EL1 tag bits in siginfo Peter Collingbourne
2020-11-02 17:54   ` Dave Martin
2020-11-03  3:59     ` Peter Collingbourne
2020-11-03 11:49       ` Dave Martin

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