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Commit dbbfe487 authored Sep 27, 2013 by Martin Schwidefsky

s390: fix system call restart after inferior call



Git commit 61649881 "s390: system call path micro optimization"
introduced a regression in regard to system call restarting and inferior
function calls via the ptrace interface. The pointer to the system call
table needs to be loaded in sysc_sigpending if do_signal returns with
TIF_SYSCALl set after it restored a system call context.

Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

parent 4d3b0664

arch/s390/kernel/entry.S

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -266,6 +266,7 @@ sysc_sigpending:
	tm __TI_flags+3(%r12),_TIF_SYSCALL		tm __TI_flags+3(%r12),_TIF_SYSCALL
	jno sysc_return		jno sysc_return
	lm %r2,%r7,__PT_R2(%r11) # load svc arguments		lm %r2,%r7,__PT_R2(%r11) # load svc arguments
			l %r10,__TI_sysc_table(%r12) # 31 bit system call table
	xr %r8,%r8 # svc 0 returns -ENOSYS		xr %r8,%r8 # svc 0 returns -ENOSYS
	clc __PT_INT_CODE+2(2,%r11),BASED(.Lnr_syscalls+2)		clc __PT_INT_CODE+2(2,%r11),BASED(.Lnr_syscalls+2)
	jnl sysc_nr_ok # invalid svc number -> do svc 0		jnl sysc_nr_ok # invalid svc number -> do svc 0

arch/s390/kernel/entry64.S

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -297,6 +297,7 @@ sysc_sigpending:
	tm __TI_flags+7(%r12),_TIF_SYSCALL		tm __TI_flags+7(%r12),_TIF_SYSCALL
	jno sysc_return		jno sysc_return
	lmg %r2,%r7,__PT_R2(%r11) # load svc arguments		lmg %r2,%r7,__PT_R2(%r11) # load svc arguments
			lg %r10,__TI_sysc_table(%r12) # address of system call table
	lghi %r8,0 # svc 0 returns -ENOSYS		lghi %r8,0 # svc 0 returns -ENOSYS
	llgh %r1,__PT_INT_CODE+2(%r11) # load new svc number		llgh %r1,__PT_INT_CODE+2(%r11) # load new svc number
	cghi %r1,NR_syscalls		cghi %r1,NR_syscalls