[PATCH] signal: Don't init struct kernel_siginfo fields to zero again

From: Leesoo Ahn
Date: Sun Dec 20 2020 - 02:49:30 EST


clear_siginfo() is responsible for clearing struct kernel_siginfo object.
It's obvious that manually initializing those fields is needless as
a commit[1] explains why the function introduced and its guarantee that
all bits in the struct are cleared after it.

[1]: commit 8c5dbf2ae00b ("signal: Introduce clear_siginfo")

Signed-off-by: Leesoo Ahn <lsahn@xxxxxxxxxx>
---
kernel/signal.c | 21 ---------------------
1 file changed, 21 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index 5736c55aaa1a..8f49fa3ade33 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -603,10 +603,7 @@ static void collect_signal(int sig, struct sigpending *list, kernel_siginfo_t *i
*/
clear_siginfo(info);
info->si_signo = sig;
- info->si_errno = 0;
info->si_code = SI_USER;
- info->si_pid = 0;
- info->si_uid = 0;
}
}

@@ -1120,7 +1117,6 @@ static int __send_signal(int sig, struct kernel_siginfo *info, struct task_struc
case (unsigned long) SEND_SIG_NOINFO:
clear_siginfo(&q->info);
q->info.si_signo = sig;
- q->info.si_errno = 0;
q->info.si_code = SI_USER;
q->info.si_pid = task_tgid_nr_ns(current,
task_active_pid_ns(t));
@@ -1133,10 +1129,7 @@ static int __send_signal(int sig, struct kernel_siginfo *info, struct task_struc
case (unsigned long) SEND_SIG_PRIV:
clear_siginfo(&q->info);
q->info.si_signo = sig;
- q->info.si_errno = 0;
q->info.si_code = SI_KERNEL;
- q->info.si_pid = 0;
- q->info.si_uid = 0;
break;
default:
copy_siginfo(&q->info, info);
@@ -1623,10 +1616,7 @@ void force_sig(int sig)

clear_siginfo(&info);
info.si_signo = sig;
- info.si_errno = 0;
info.si_code = SI_KERNEL;
- info.si_pid = 0;
- info.si_uid = 0;
force_sig_info(&info);
}
EXPORT_SYMBOL(force_sig);
@@ -1659,7 +1649,6 @@ int force_sig_fault_to_task(int sig, int code, void __user *addr

clear_siginfo(&info);
info.si_signo = sig;
- info.si_errno = 0;
info.si_code = code;
info.si_addr = addr;
#ifdef __ARCH_SI_TRAPNO
@@ -1691,7 +1680,6 @@ int send_sig_fault(int sig, int code, void __user *addr

clear_siginfo(&info);
info.si_signo = sig;
- info.si_errno = 0;
info.si_code = code;
info.si_addr = addr;
#ifdef __ARCH_SI_TRAPNO
@@ -1712,7 +1700,6 @@ 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;
info.si_addr_lsb = lsb;
@@ -1726,7 +1713,6 @@ 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;
info.si_addr_lsb = lsb;
@@ -1740,7 +1726,6 @@ int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper)

clear_siginfo(&info);
info.si_signo = SIGSEGV;
- info.si_errno = 0;
info.si_code = SEGV_BNDERR;
info.si_addr = addr;
info.si_lower = lower;
@@ -1755,7 +1740,6 @@ int force_sig_pkuerr(void __user *addr, u32 pkey)

clear_siginfo(&info);
info.si_signo = SIGSEGV;
- info.si_errno = 0;
info.si_code = SEGV_PKUERR;
info.si_addr = addr;
info.si_pkey = pkey;
@@ -1934,7 +1918,6 @@ bool do_notify_parent(struct task_struct *tsk, int sig)

clear_siginfo(&info);
info.si_signo = sig;
- info.si_errno = 0;
/*
* We are under tasklist_lock here so our parent is tied to
* us and cannot change.
@@ -2033,7 +2016,6 @@ static void do_notify_parent_cldstop(struct task_struct *tsk,

clear_siginfo(&info);
info.si_signo = SIGCHLD;
- info.si_errno = 0;
/*
* see comment in do_notify_parent() about the following 4 lines
*/
@@ -2506,7 +2488,6 @@ static int ptrace_signal(int signr, kernel_siginfo_t *info)
if (signr != info->si_signo) {
clear_siginfo(info);
info->si_signo = signr;
- info->si_errno = 0;
info->si_code = SI_USER;
rcu_read_lock();
info->si_pid = task_pid_vnr(current->parent);
@@ -3660,7 +3641,6 @@ static inline void prepare_kill_siginfo(int sig, struct kernel_siginfo *info)
{
clear_siginfo(info);
info->si_signo = sig;
- info->si_errno = 0;
info->si_code = SI_USER;
info->si_pid = task_tgid_vnr(current);
info->si_uid = from_kuid_munged(current_user_ns(), current_uid());
@@ -3833,7 +3813,6 @@ static int do_tkill(pid_t tgid, pid_t pid, int sig)

clear_siginfo(&info);
info.si_signo = sig;
- info.si_errno = 0;
info.si_code = SI_TKILL;
info.si_pid = task_tgid_vnr(current);
info.si_uid = from_kuid_munged(current_user_ns(), current_uid());
--
2.26.2