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Diffstat (limited to 'arch/s390/kernel/signal.c')
-rw-r--r--arch/s390/kernel/signal.c128
1 files changed, 70 insertions, 58 deletions
diff --git a/arch/s390/kernel/signal.c b/arch/s390/kernel/signal.c
index 9a40e1cc5ec..05a85bc14c9 100644
--- a/arch/s390/kernel/signal.c
+++ b/arch/s390/kernel/signal.c
@@ -30,6 +30,7 @@
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/lowcore.h>
+#include <asm/compat.h>
#include "entry.h"
#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
@@ -116,7 +117,8 @@ static int save_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
/* Copy a 'clean' PSW mask to the user to avoid leaking
information about whether PER is currently on. */
- user_sregs.regs.psw.mask = PSW_MASK_MERGE(psw_user_bits, regs->psw.mask);
+ user_sregs.regs.psw.mask = psw_user_bits |
+ (regs->psw.mask & PSW_MASK_USER);
user_sregs.regs.psw.addr = regs->psw.addr;
memcpy(&user_sregs.regs.gprs, &regs->gprs, sizeof(sregs->regs.gprs));
memcpy(&user_sregs.regs.acrs, current->thread.acrs,
@@ -143,9 +145,13 @@ static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
err = __copy_from_user(&user_sregs, sregs, sizeof(_sigregs));
if (err)
return err;
- regs->psw.mask = PSW_MASK_MERGE(regs->psw.mask,
- user_sregs.regs.psw.mask);
- regs->psw.addr = PSW_ADDR_AMODE | user_sregs.regs.psw.addr;
+ /* Use regs->psw.mask instead of psw_user_bits to preserve PER bit. */
+ regs->psw.mask = (regs->psw.mask & ~PSW_MASK_USER) |
+ (user_sregs.regs.psw.mask & PSW_MASK_USER);
+ /* Check for invalid amode */
+ if (regs->psw.mask & PSW_MASK_EA)
+ regs->psw.mask |= PSW_MASK_BA;
+ regs->psw.addr = user_sregs.regs.psw.addr;
memcpy(&regs->gprs, &user_sregs.regs.gprs, sizeof(sregs->regs.gprs));
memcpy(&current->thread.acrs, &user_sregs.regs.acrs,
sizeof(sregs->regs.acrs));
@@ -156,7 +162,7 @@ static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
current->thread.fp_regs.fpc &= FPC_VALID_MASK;
restore_fp_regs(&current->thread.fp_regs);
- regs->svcnr = 0; /* disable syscall checks */
+ clear_thread_flag(TIF_SYSCALL); /* No longer in a system call */
return 0;
}
@@ -288,6 +294,7 @@ static int setup_frame(int sig, struct k_sigaction *ka,
/* Set up registers for signal handler */
regs->gprs[15] = (unsigned long) frame;
+ regs->psw.mask |= PSW_MASK_EA | PSW_MASK_BA; /* 64 bit amode */
regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
regs->gprs[2] = map_signal(sig);
@@ -356,6 +363,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
/* Set up registers for signal handler */
regs->gprs[15] = (unsigned long) frame;
+ regs->psw.mask |= PSW_MASK_EA | PSW_MASK_BA; /* 64 bit amode */
regs->psw.addr = (unsigned long) ka->sa.sa_handler | PSW_ADDR_AMODE;
regs->gprs[2] = map_signal(sig);
@@ -401,7 +409,6 @@ static int handle_signal(unsigned long sig, struct k_sigaction *ka,
*/
void do_signal(struct pt_regs *regs)
{
- unsigned long retval = 0, continue_addr = 0, restart_addr = 0;
siginfo_t info;
int signr;
struct k_sigaction ka;
@@ -421,54 +428,45 @@ void do_signal(struct pt_regs *regs)
else
oldset = &current->blocked;
- /* Are we from a system call? */
- if (regs->svcnr) {
- continue_addr = regs->psw.addr;
- restart_addr = continue_addr - regs->ilc;
- retval = regs->gprs[2];
-
- /* Prepare for system call restart. We do this here so that a
- debugger will see the already changed PSW. */
- switch (retval) {
- case -ERESTARTNOHAND:
- case -ERESTARTSYS:
- case -ERESTARTNOINTR:
- regs->gprs[2] = regs->orig_gpr2;
- regs->psw.addr = restart_addr;
- break;
- case -ERESTART_RESTARTBLOCK:
- regs->gprs[2] = -EINTR;
- }
- regs->svcnr = 0; /* Don't deal with this again. */
- }
-
- /* Get signal to deliver. When running under ptrace, at this point
- the debugger may change all our registers ... */
+ /*
+ * Get signal to deliver. When running under ptrace, at this point
+ * the debugger may change all our registers, including the system
+ * call information.
+ */
+ current_thread_info()->system_call =
+ test_thread_flag(TIF_SYSCALL) ? regs->svc_code : 0;
signr = get_signal_to_deliver(&info, &ka, regs, NULL);
- /* Depending on the signal settings we may need to revert the
- decision to restart the system call. */
- if (signr > 0 && regs->psw.addr == restart_addr) {
- if (retval == -ERESTARTNOHAND
- || (retval == -ERESTARTSYS
- && !(current->sighand->action[signr-1].sa.sa_flags
- & SA_RESTART))) {
- regs->gprs[2] = -EINTR;
- regs->psw.addr = continue_addr;
- }
- }
-
if (signr > 0) {
/* Whee! Actually deliver the signal. */
- int ret;
-#ifdef CONFIG_COMPAT
- if (is_compat_task()) {
- ret = handle_signal32(signr, &ka, &info, oldset, regs);
- }
- else
-#endif
- ret = handle_signal(signr, &ka, &info, oldset, regs);
- if (!ret) {
+ if (current_thread_info()->system_call) {
+ regs->svc_code = current_thread_info()->system_call;
+ /* Check for system call restarting. */
+ switch (regs->gprs[2]) {
+ case -ERESTART_RESTARTBLOCK:
+ case -ERESTARTNOHAND:
+ regs->gprs[2] = -EINTR;
+ break;
+ case -ERESTARTSYS:
+ if (!(ka.sa.sa_flags & SA_RESTART)) {
+ regs->gprs[2] = -EINTR;
+ break;
+ }
+ /* fallthrough */
+ case -ERESTARTNOINTR:
+ regs->gprs[2] = regs->orig_gpr2;
+ regs->psw.addr =
+ __rewind_psw(regs->psw,
+ regs->svc_code >> 16);
+ break;
+ }
+ /* No longer in a system call */
+ clear_thread_flag(TIF_SYSCALL);
+ }
+
+ if ((is_compat_task() ?
+ handle_signal32(signr, &ka, &info, oldset, regs) :
+ handle_signal(signr, &ka, &info, oldset, regs)) == 0) {
/*
* A signal was successfully delivered; the saved
* sigmask will have been stored in the signal frame,
@@ -482,11 +480,32 @@ void do_signal(struct pt_regs *regs)
* Let tracing know that we've done the handler setup.
*/
tracehook_signal_handler(signr, &info, &ka, regs,
- test_thread_flag(TIF_SINGLE_STEP));
+ test_thread_flag(TIF_SINGLE_STEP));
}
return;
}
+ /* No handlers present - check for system call restart */
+ if (current_thread_info()->system_call) {
+ regs->svc_code = current_thread_info()->system_call;
+ switch (regs->gprs[2]) {
+ case -ERESTART_RESTARTBLOCK:
+ /* Restart with sys_restart_syscall */
+ regs->svc_code = __NR_restart_syscall;
+ /* fallthrough */
+ case -ERESTARTNOHAND:
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR:
+ /* Restart system call with magic TIF bit. */
+ regs->gprs[2] = regs->orig_gpr2;
+ set_thread_flag(TIF_SYSCALL);
+ break;
+ default:
+ clear_thread_flag(TIF_SYSCALL);
+ break;
+ }
+ }
+
/*
* If there's no signal to deliver, we just put the saved sigmask back.
*/
@@ -494,13 +513,6 @@ void do_signal(struct pt_regs *regs)
clear_thread_flag(TIF_RESTORE_SIGMASK);
sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
}
-
- /* Restart a different system call. */
- if (retval == -ERESTART_RESTARTBLOCK
- && regs->psw.addr == continue_addr) {
- regs->gprs[2] = __NR_restart_syscall;
- set_thread_flag(TIF_RESTART_SVC);
- }
}
void do_notify_resume(struct pt_regs *regs)
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-09 19:21:34 +0000