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xtensa: use generic tracehooks 

Use tracehook_report_syscall_{entry,exit} instead of a local copy of it
in do_syscall_trace. Allow tracehook to cancel syscall by returning
invalid syscall number to the system_call function.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
This commit is contained in:
Max Filippov 2015-03-16 14:40:14 +03:00
parent 0700ed072f
commit f984409a00
2 changed files with 14 additions and 27 deletions
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3
arch/xtensa/kernel/entry.S
View File

@ -1899,10 +1899,11 @@ ENTRY(system_call)
movi a4, do_syscall_trace_enter
s32i a3, a2, PT_SYSCALL
callx4 a4
mov a3, a6
/* syscall = sys_call_table[syscall_nr] */
movi a4, sys_call_table;
movi a4, sys_call_table
movi a5, __NR_syscall_count
movi a6, -ENOSYS
bgeu a3, a5, 1f

38
arch/xtensa/kernel/ptrace.c
View File

@ -23,6 +23,7 @@
#include <linux/security.h>
#include <linux/signal.h>
#include <linux/smp.h>
#include <linux/tracehook.h>
#include <linux/uaccess.h>
#include <asm/coprocessor.h>
@ -468,36 +469,21 @@ long arch_ptrace(struct task_struct *child, long request,
return ret;
}
void do_syscall_trace(void)
{
/*
* The 0x80 provides a way for the tracing parent to distinguish
* between a syscall stop and SIGTRAP delivery
*/
ptrace_notify(SIGTRAP |
((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0));
/*
* this isn't the same as continuing with a signal, but it will do
* for normal use. strace only continues with a signal if the
* stopping signal is not SIGTRAP. -brl
*/
if (current->exit_code) {
send_sig(current->exit_code, current, 1);
current->exit_code = 0;
}
}
void do_syscall_trace_enter(struct pt_regs *regs)
unsigned long do_syscall_trace_enter(struct pt_regs *regs)
{
if (test_thread_flag(TIF_SYSCALL_TRACE) &&
(current->ptrace & PT_PTRACED))
do_syscall_trace();
tracehook_report_syscall_entry(regs))
return -1;
return regs->areg[2];
}
void do_syscall_trace_leave(struct pt_regs *regs)
{
if (test_thread_flag(TIF_SYSCALL_TRACE) &&
(current->ptrace & PT_PTRACED))
do_syscall_trace();
int step;
step = test_thread_flag(TIF_SINGLESTEP);
if (step || test_thread_flag(TIF_SYSCALL_TRACE))
tracehook_report_syscall_exit(regs, step);
}