[PATCH v13 6/8] signal: deduplicate code dealing with common _sigfault fields
Peter Collingbourne
pcc at google.com
Mon Nov 2 23:09:42 EST 2020
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 at 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 b256f9c65661..e9fb05041e7a 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 8f34819e80de..d18930aafbf4 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1650,6 +1650,15 @@ 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)
@@ -1658,10 +1667,7 @@ 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
@@ -1690,10 +1696,7 @@ 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
@@ -1711,10 +1714,7 @@ 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);
}
@@ -1725,10 +1725,7 @@ 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);
}
@@ -1739,10 +1736,7 @@ 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);
@@ -1754,10 +1748,7 @@ 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);
}
@@ -1771,10 +1762,8 @@ 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);
}
@@ -3267,12 +3256,23 @@ 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;
@@ -3287,31 +3287,15 @@ 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:
@@ -3348,11 +3332,22 @@ 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;
@@ -3367,31 +3362,15 @@ 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:
--
2.29.1.341.ge80a0c044ae-goog
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