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author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2008-11-27 11:05:55 +0100 |
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committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2008-11-27 11:06:56 +0100 |
commit | 59da21398e680e8100625d689c8bebee6a139e93 (patch) | |
tree | 7d93f87d2942dac06367af8b3a269e9f6d557b29 /arch/s390/kernel/entry.S | |
parent | ed313489badef16d700f5a3be50e8fd8f8294bc8 (diff) | |
download | linux-59da21398e680e8100625d689c8bebee6a139e93.tar.bz2 |
[S390] fix system call parameter functions.
syscall_get_nr() currently returns a valid result only if the call
chain of the traced process includes do_syscall_trace_enter(). But
collect_syscall() can be called for any sleeping task, the result of
syscall_get_nr() in general is completely bogus.
To make syscall_get_nr() work for any sleeping task the traps field
in pt_regs is replace with svcnr - the system call number the process
is executing. If svcnr == 0 the process is not on a system call path.
The syscall_get_arguments and syscall_set_arguments use regs->gprs[2]
for the first system call parameter. This is incorrect since gprs[2]
may have been overwritten with the system call number if the call
chain includes do_syscall_trace_enter. Use regs->orig_gprs2 instead.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/entry.S')
-rw-r--r-- | arch/s390/kernel/entry.S | 21 |
1 files changed, 11 insertions, 10 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S index 08844fc24a2e..198ea18a534d 100644 --- a/arch/s390/kernel/entry.S +++ b/arch/s390/kernel/entry.S @@ -46,7 +46,7 @@ SP_R14 = STACK_FRAME_OVERHEAD + __PT_GPRS + 56 SP_R15 = STACK_FRAME_OVERHEAD + __PT_GPRS + 60 SP_ORIG_R2 = STACK_FRAME_OVERHEAD + __PT_ORIG_GPR2 SP_ILC = STACK_FRAME_OVERHEAD + __PT_ILC -SP_TRAP = STACK_FRAME_OVERHEAD + __PT_TRAP +SP_SVCNR = STACK_FRAME_OVERHEAD + __PT_SVCNR SP_SIZE = STACK_FRAME_OVERHEAD + __PT_SIZE _TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \ @@ -183,11 +183,10 @@ STACK_SIZE = 1 << STACK_SHIFT .macro CREATE_STACK_FRAME psworg,savearea s %r15,BASED(.Lc_spsize) # make room for registers & psw mvc SP_PSW(8,%r15),0(%r12) # move user PSW to stack - la %r12,\psworg st %r2,SP_ORIG_R2(%r15) # store original content of gpr 2 - icm %r12,12,__LC_SVC_ILC + icm %r12,3,__LC_SVC_ILC stm %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack - st %r12,SP_ILC(%r15) + st %r12,SP_SVCNR(%r15) mvc SP_R12(16,%r15),\savearea # move %r12-%r15 to stack la %r12,0 st %r12,__SF_BACKCHAIN(%r15) # clear back chain @@ -264,16 +263,17 @@ sysc_update: #endif sysc_do_svc: l %r9,__LC_THREAD_INFO # load pointer to thread_info struct - sla %r7,2 # *4 and test for svc 0 + ltr %r7,%r7 # test for svc 0 bnz BASED(sysc_nr_ok) # svc number > 0 # svc 0: system call number in %r1 cl %r1,BASED(.Lnr_syscalls) bnl BASED(sysc_nr_ok) lr %r7,%r1 # copy svc number to %r7 - sla %r7,2 # *4 sysc_nr_ok: mvc SP_ARGS(4,%r15),SP_R7(%r15) sysc_do_restart: + sth %r7,SP_SVCNR(%r15) + sll %r7,2 # svc number *4 l %r8,BASED(.Lsysc_table) tm __TI_flags+3(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT) l %r8,0(%r7,%r8) # get system call addr. @@ -376,7 +376,6 @@ sysc_notify_resume: sysc_restart: ni __TI_flags+3(%r9),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC l %r7,SP_R2(%r15) # load new svc number - sla %r7,2 mvc SP_R2(4,%r15),SP_ORIG_R2(%r15) # restore first argument lm %r2,%r6,SP_R2(%r15) # load svc arguments b BASED(sysc_do_restart) # restart svc @@ -386,7 +385,8 @@ sysc_restart: # sysc_singlestep: ni __TI_flags+3(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP - mvi SP_TRAP+1(%r15),0x28 # set trap indication to pgm check + mvi SP_SVCNR(%r15),0xff # set trap indication to pgm check + mvi SP_SVCNR+1(%r15),0xff la %r2,SP_PTREGS(%r15) # address of register-save area l %r1,BASED(.Lhandle_per) # load adr. of per handler la %r14,BASED(sysc_return) # load adr. of system return @@ -407,7 +407,7 @@ sysc_tracesys: bnl BASED(sysc_tracenogo) l %r8,BASED(.Lsysc_table) lr %r7,%r2 - sll %r7,2 # *4 + sll %r7,2 # svc number *4 l %r8,0(%r7,%r8) sysc_tracego: lm %r3,%r6,SP_R3(%r15) @@ -586,7 +586,8 @@ pgm_svcper: # per was called from kernel, must be kprobes # kernel_per: - mvi SP_TRAP+1(%r15),0x28 # set trap indication to pgm check + mvi SP_SVCNR(%r15),0xff # set trap indication to pgm check + mvi SP_SVCNR+1(%r15),0xff la %r2,SP_PTREGS(%r15) # address of register-save area l %r1,BASED(.Lhandle_per) # load adr. of per handler la %r14,BASED(sysc_restore)# load adr. of system return |