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Commit cfc9066b authored by Martin Schwidefsky's avatar Martin Schwidefsky
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[S390] remove reset of system call restart on psw changes 



git commit 20b40a79 "signal race with restarting system calls"
added code to the poke_user/poke_user_compat to reset the system call
restart information in the thread-info if the PSW address is changed.
The purpose of that change has been to workaround old gdbs that do
not know about the REGSET_SYSTEM_CALL. It turned out that this is not
a good idea, it makes the behaviour of the debuggee dependent on the
order of specific ptrace call, e.g. the REGSET_SYSTEM_CALL register
set needs to be written last. And the workaround does not really fix
old gdbs, inferior calls on interrupted restarting system calls do not
work either way.

Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent b934069c

arch/s390/kernel/ptrace.c

+0 −12
Original line number Diff line number Diff line
@@ -296,13 +296,6 @@ static int __poke_user(struct task_struct *child, addr_t addr, addr_t data) 
		     ((data & PSW_MASK_EA) && !(data & PSW_MASK_BA))))

			/* Invalid psw mask. */

			return -EINVAL;

		if (addr == (addr_t) &dummy->regs.psw.addr)

			/*

			 * The debugger changed the instruction address,

			 * reset system call restart, see signal.c:do_signal

			 */

			task_thread_info(child)->system_call = 0;



		*(addr_t *)((addr_t) &task_pt_regs(child)->psw + addr) = data;



	} else if (addr < (addr_t) (&dummy->regs.orig_gpr2)) {
@@ -614,11 +607,6 @@ static int __poke_user_compat(struct task_struct *child, 
			/* Transfer 31 bit amode bit to psw mask. */

			regs->psw.mask = (regs->psw.mask & ~PSW_MASK_BA) |

				(__u64)(tmp & PSW32_ADDR_AMODE);

			/*

			 * The debugger changed the instruction address,

			 * reset system call restart, see signal.c:do_signal

			 */

			task_thread_info(child)->system_call = 0;

		} else {

			/* gpr 0-15 */

			*(__u32*)((addr_t) &regs->psw + addr*2 + 4) = tmp;