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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-12 13:55:32 +00:00
[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>
This commit is contained in:
parent
ed313489ba
commit
59da21398e
8 changed files with 44 additions and 42 deletions
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@ -321,8 +321,8 @@ struct pt_regs
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psw_t psw;
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unsigned long gprs[NUM_GPRS];
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unsigned long orig_gpr2;
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unsigned short svcnr;
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unsigned short ilc;
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unsigned short trap;
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};
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#endif
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@ -17,9 +17,7 @@
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static inline long syscall_get_nr(struct task_struct *task,
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struct pt_regs *regs)
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{
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if (regs->trap != __LC_SVC_OLD_PSW)
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return -1;
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return regs->gprs[2];
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return regs->svcnr ? regs->svcnr : -1;
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}
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static inline void syscall_rollback(struct task_struct *task,
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@ -52,18 +50,20 @@ static inline void syscall_get_arguments(struct task_struct *task,
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unsigned int i, unsigned int n,
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unsigned long *args)
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{
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unsigned long mask = -1UL;
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BUG_ON(i + n > 6);
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#ifdef CONFIG_COMPAT
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if (test_tsk_thread_flag(task, TIF_31BIT)) {
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if (i + n == 6)
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args[--n] = (u32) regs->args[0];
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while (n-- > 0)
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args[n] = (u32) regs->gprs[2 + i + n];
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}
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if (test_tsk_thread_flag(task, TIF_31BIT))
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mask = 0xffffffff;
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#endif
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if (i + n == 6)
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args[--n] = regs->args[0];
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memcpy(args, ®s->gprs[2 + i], n * sizeof(args[0]));
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args[--n] = regs->args[0] & mask;
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while (n-- > 0)
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if (i + n > 0)
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args[n] = regs->gprs[2 + i + n] & mask;
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if (i == 0)
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args[0] = regs->orig_gpr2 & mask;
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}
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static inline void syscall_set_arguments(struct task_struct *task,
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@ -74,7 +74,11 @@ static inline void syscall_set_arguments(struct task_struct *task,
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BUG_ON(i + n > 6);
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if (i + n == 6)
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regs->args[0] = args[--n];
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memcpy(®s->gprs[2 + i], args, n * sizeof(args[0]));
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while (n-- > 0)
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if (i + n > 0)
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regs->gprs[2 + i + n] = args[n];
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if (i == 0)
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regs->orig_gpr2 = args[0];
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}
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#endif /* _ASM_SYSCALL_H */
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@ -32,7 +32,7 @@ int main(void)
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DEFINE(__PT_GPRS, offsetof(struct pt_regs, gprs));
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DEFINE(__PT_ORIG_GPR2, offsetof(struct pt_regs, orig_gpr2));
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DEFINE(__PT_ILC, offsetof(struct pt_regs, ilc));
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DEFINE(__PT_TRAP, offsetof(struct pt_regs, trap));
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DEFINE(__PT_SVCNR, offsetof(struct pt_regs, svcnr));
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DEFINE(__PT_SIZE, sizeof(struct pt_regs));
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BLANK();
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DEFINE(__SF_BACKCHAIN, offsetof(struct stack_frame, back_chain));
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@ -340,7 +340,7 @@ static int restore_sigregs32(struct pt_regs *regs,_sigregs32 __user *sregs)
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return err;
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restore_fp_regs(¤t->thread.fp_regs);
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regs->trap = -1; /* disable syscall checks */
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regs->svcnr = 0; /* disable syscall checks */
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return 0;
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}
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@ -46,7 +46,7 @@ SP_R14 = STACK_FRAME_OVERHEAD + __PT_GPRS + 56
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SP_R15 = STACK_FRAME_OVERHEAD + __PT_GPRS + 60
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SP_ORIG_R2 = STACK_FRAME_OVERHEAD + __PT_ORIG_GPR2
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SP_ILC = STACK_FRAME_OVERHEAD + __PT_ILC
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SP_TRAP = STACK_FRAME_OVERHEAD + __PT_TRAP
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SP_SVCNR = STACK_FRAME_OVERHEAD + __PT_SVCNR
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SP_SIZE = STACK_FRAME_OVERHEAD + __PT_SIZE
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_TIF_WORK_SVC = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
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@ -183,11 +183,10 @@ STACK_SIZE = 1 << STACK_SHIFT
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.macro CREATE_STACK_FRAME psworg,savearea
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s %r15,BASED(.Lc_spsize) # make room for registers & psw
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mvc SP_PSW(8,%r15),0(%r12) # move user PSW to stack
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la %r12,\psworg
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st %r2,SP_ORIG_R2(%r15) # store original content of gpr 2
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icm %r12,12,__LC_SVC_ILC
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icm %r12,3,__LC_SVC_ILC
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stm %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack
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st %r12,SP_ILC(%r15)
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st %r12,SP_SVCNR(%r15)
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mvc SP_R12(16,%r15),\savearea # move %r12-%r15 to stack
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la %r12,0
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st %r12,__SF_BACKCHAIN(%r15) # clear back chain
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@ -264,16 +263,17 @@ sysc_update:
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#endif
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sysc_do_svc:
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l %r9,__LC_THREAD_INFO # load pointer to thread_info struct
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sla %r7,2 # *4 and test for svc 0
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ltr %r7,%r7 # test for svc 0
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bnz BASED(sysc_nr_ok) # svc number > 0
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# svc 0: system call number in %r1
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cl %r1,BASED(.Lnr_syscalls)
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bnl BASED(sysc_nr_ok)
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lr %r7,%r1 # copy svc number to %r7
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sla %r7,2 # *4
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sysc_nr_ok:
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mvc SP_ARGS(4,%r15),SP_R7(%r15)
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sysc_do_restart:
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sth %r7,SP_SVCNR(%r15)
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sll %r7,2 # svc number *4
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l %r8,BASED(.Lsysc_table)
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tm __TI_flags+3(%r9),(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT)
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l %r8,0(%r7,%r8) # get system call addr.
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@ -376,7 +376,6 @@ sysc_notify_resume:
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sysc_restart:
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ni __TI_flags+3(%r9),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC
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l %r7,SP_R2(%r15) # load new svc number
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sla %r7,2
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mvc SP_R2(4,%r15),SP_ORIG_R2(%r15) # restore first argument
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lm %r2,%r6,SP_R2(%r15) # load svc arguments
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b BASED(sysc_do_restart) # restart svc
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@ -386,7 +385,8 @@ sysc_restart:
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#
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sysc_singlestep:
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ni __TI_flags+3(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
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mvi SP_TRAP+1(%r15),0x28 # set trap indication to pgm check
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mvi SP_SVCNR(%r15),0xff # set trap indication to pgm check
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mvi SP_SVCNR+1(%r15),0xff
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la %r2,SP_PTREGS(%r15) # address of register-save area
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l %r1,BASED(.Lhandle_per) # load adr. of per handler
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la %r14,BASED(sysc_return) # load adr. of system return
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@ -407,7 +407,7 @@ sysc_tracesys:
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bnl BASED(sysc_tracenogo)
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l %r8,BASED(.Lsysc_table)
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lr %r7,%r2
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sll %r7,2 # *4
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sll %r7,2 # svc number *4
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l %r8,0(%r7,%r8)
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sysc_tracego:
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lm %r3,%r6,SP_R3(%r15)
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@ -586,7 +586,8 @@ pgm_svcper:
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# per was called from kernel, must be kprobes
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#
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kernel_per:
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mvi SP_TRAP+1(%r15),0x28 # set trap indication to pgm check
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mvi SP_SVCNR(%r15),0xff # set trap indication to pgm check
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mvi SP_SVCNR+1(%r15),0xff
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la %r2,SP_PTREGS(%r15) # address of register-save area
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l %r1,BASED(.Lhandle_per) # load adr. of per handler
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la %r14,BASED(sysc_restore)# load adr. of system return
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@ -46,7 +46,7 @@ SP_R14 = STACK_FRAME_OVERHEAD + __PT_GPRS + 112
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SP_R15 = STACK_FRAME_OVERHEAD + __PT_GPRS + 120
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SP_ORIG_R2 = STACK_FRAME_OVERHEAD + __PT_ORIG_GPR2
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SP_ILC = STACK_FRAME_OVERHEAD + __PT_ILC
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SP_TRAP = STACK_FRAME_OVERHEAD + __PT_TRAP
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SP_SVCNR = STACK_FRAME_OVERHEAD + __PT_SVCNR
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SP_SIZE = STACK_FRAME_OVERHEAD + __PT_SIZE
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STACK_SHIFT = PAGE_SHIFT + THREAD_ORDER
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@ -171,11 +171,10 @@ _TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \
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.macro CREATE_STACK_FRAME psworg,savearea
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aghi %r15,-SP_SIZE # make room for registers & psw
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mvc SP_PSW(16,%r15),0(%r12) # move user PSW to stack
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la %r12,\psworg
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stg %r2,SP_ORIG_R2(%r15) # store original content of gpr 2
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icm %r12,12,__LC_SVC_ILC
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icm %r12,3,__LC_SVC_ILC
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stmg %r0,%r11,SP_R0(%r15) # store gprs %r0-%r11 to kernel stack
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st %r12,SP_ILC(%r15)
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st %r12,SP_SVCNR(%r15)
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mvc SP_R12(32,%r15),\savearea # move %r12-%r15 to stack
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la %r12,0
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stg %r12,__SF_BACKCHAIN(%r15)
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@ -250,16 +249,17 @@ sysc_update:
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#endif
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sysc_do_svc:
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lg %r9,__LC_THREAD_INFO # load pointer to thread_info struct
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slag %r7,%r7,2 # *4 and test for svc 0
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ltgr %r7,%r7 # test for svc 0
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jnz sysc_nr_ok
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# svc 0: system call number in %r1
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cl %r1,BASED(.Lnr_syscalls)
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jnl sysc_nr_ok
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lgfr %r7,%r1 # clear high word in r1
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slag %r7,%r7,2 # svc 0: system call number in %r1
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sysc_nr_ok:
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mvc SP_ARGS(8,%r15),SP_R7(%r15)
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sysc_do_restart:
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sth %r7,SP_SVCNR(%r15)
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sllg %r7,%r7,2 # svc number * 4
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larl %r10,sys_call_table
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#ifdef CONFIG_COMPAT
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tm __TI_flags+5(%r9),(_TIF_31BIT>>16) # running in 31 bit mode ?
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@ -363,7 +363,6 @@ sysc_notify_resume:
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sysc_restart:
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ni __TI_flags+7(%r9),255-_TIF_RESTART_SVC # clear TIF_RESTART_SVC
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lg %r7,SP_R2(%r15) # load new svc number
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slag %r7,%r7,2 # *4
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mvc SP_R2(8,%r15),SP_ORIG_R2(%r15) # restore first argument
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lmg %r2,%r6,SP_R2(%r15) # load svc arguments
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j sysc_do_restart # restart svc
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@ -372,9 +371,8 @@ sysc_restart:
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# _TIF_SINGLE_STEP is set, call do_single_step
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#
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sysc_singlestep:
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ni __TI_flags+7(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
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lhi %r0,__LC_PGM_OLD_PSW
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sth %r0,SP_TRAP(%r15) # set trap indication to pgm check
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ni __TI_flags+7(%r9),255-_TIF_SINGLE_STEP # clear TIF_SINGLE_STEP
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xc SP_SVCNR(2,%r15),SP_SVCNR(%r15) # clear svc number
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la %r2,SP_PTREGS(%r15) # address of register-save area
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larl %r14,sysc_return # load adr. of system return
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jg do_single_step # branch to do_sigtrap
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@ -392,7 +390,7 @@ sysc_tracesys:
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lghi %r0,NR_syscalls
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clgr %r0,%r2
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jnh sysc_tracenogo
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slag %r7,%r2,2 # *4
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sllg %r7,%r2,2 # svc number *4
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lgf %r8,0(%r7,%r10)
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sysc_tracego:
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lmg %r3,%r6,SP_R3(%r15)
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@ -567,8 +565,7 @@ pgm_svcper:
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# per was called from kernel, must be kprobes
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#
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kernel_per:
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lhi %r0,__LC_PGM_OLD_PSW
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sth %r0,SP_TRAP(%r15) # set trap indication to pgm check
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xc SP_SVCNR(2,%r15),SP_SVCNR(%r15) # clear svc number
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la %r2,SP_PTREGS(%r15) # address of register-save area
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larl %r14,sysc_restore # load adr. of system ret, no work
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jg do_single_step # branch to do_single_step
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@ -657,7 +657,7 @@ asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
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* debugger stored an invalid system call number. Skip
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* the system call and the system call restart handling.
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*/
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regs->trap = -1;
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regs->svcnr = 0;
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ret = -1;
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}
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@ -160,7 +160,7 @@ static int restore_sigregs(struct pt_regs *regs, _sigregs __user *sregs)
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current->thread.fp_regs.fpc &= FPC_VALID_MASK;
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restore_fp_regs(¤t->thread.fp_regs);
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regs->trap = -1; /* disable syscall checks */
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regs->svcnr = 0; /* disable syscall checks */
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return 0;
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}
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@ -445,7 +445,7 @@ void do_signal(struct pt_regs *regs)
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oldset = ¤t->blocked;
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/* Are we from a system call? */
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if (regs->trap == __LC_SVC_OLD_PSW) {
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if (regs->svcnr) {
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continue_addr = regs->psw.addr;
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restart_addr = continue_addr - regs->ilc;
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retval = regs->gprs[2];
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@ -462,7 +462,7 @@ void do_signal(struct pt_regs *regs)
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case -ERESTART_RESTARTBLOCK:
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regs->gprs[2] = -EINTR;
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}
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regs->trap = -1; /* Don't deal with this again. */
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regs->svcnr = 0; /* Don't deal with this again. */
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}
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/* Get signal to deliver. When running under ptrace, at this point
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