microblaze: Support ptrace syscall tracing. (23575483) · Commits · e / devices / android_kernel_teracube_2e

arch/microblaze/kernel/entry.S

+60 −12

Original line number	Original line	Diff line number	Diff line
	@@ -308,38 +308,69 @@ C_ENTRY(_user_exception):
	swi r12, r1, PTO+PT_R0;		swi r12, r1, PTO+PT_R0;
	tovirt(r1,r1)		tovirt(r1,r1)

	la r15, r0, ret_from_trap-8
	/* where the trap should return need -8 to adjust for rtsd r15, 8*/		/* where the trap should return need -8 to adjust for rtsd r15, 8*/
	/* Jump to the appropriate function for the system call number in r12		/* Jump to the appropriate function for the system call number in r12
	* (r12 is not preserved), or return an error if r12 is not valid. The LP		* (r12 is not preserved), or return an error if r12 is not valid. The LP
	* register should point to the location where		* register should point to the location where
	* the called function should return. [note that MAKE_SYS_CALL uses label 1] */		* the called function should return. [note that MAKE_SYS_CALL uses label 1] */
	/* See if the system call number is valid. */
			# Step into virtual mode.
			set_vms;
			addik r11, r0, 3f
			rtid r11, 0
			nop
			3:
			add r11, r0, CURRENT_TASK /* Get current task ptr into r11 */
			lwi r11, r11, TS_THREAD_INFO /* get thread info */
			lwi r11, r11, TI_FLAGS /* get flags in thread info */
			andi r11, r11, _TIF_WORK_SYSCALL_MASK
			beqi r11, 4f

			addik r3, r0, -ENOSYS
			swi r3, r1, PTO + PT_R3
			brlid r15, do_syscall_trace_enter
			addik r5, r1, PTO + PT_R0

			# do_syscall_trace_enter returns the new syscall nr.
			addk r12, r0, r3
			lwi r5, r1, PTO+PT_R5;
			lwi r6, r1, PTO+PT_R6;
			lwi r7, r1, PTO+PT_R7;
			lwi r8, r1, PTO+PT_R8;
			lwi r9, r1, PTO+PT_R9;
			lwi r10, r1, PTO+PT_R10;
			4:
			/* Jump to the appropriate function for the system call number in r12
			* (r12 is not preserved), or return an error if r12 is not valid.
			* The LP register should point to the location where the called function
			* should return. [note that MAKE_SYS_CALL uses label 1] */
			/* See if the system call number is valid */
	addi r11, r12, -__NR_syscalls;		addi r11, r12, -__NR_syscalls;
	bgei r11,1f;		bgei r11,5f;
	/* Figure out which function to use for this system call. */		/* Figure out which function to use for this system call. */
	/* Note Microblaze barrel shift is optional, so don't rely on it */		/* Note Microblaze barrel shift is optional, so don't rely on it */
	add r12, r12, r12; /* convert num -> ptr */		add r12, r12, r12; /* convert num -> ptr */
	add r12, r12, r12;		add r12, r12, r12;

	/* Trac syscalls and stored them to r0_ram */		/* Trac syscalls and stored them to r0_ram */
	lwi r3, r12, 0x400 + TOPHYS(r0_ram)		lwi r3, r12, 0x400 + r0_ram
	addi r3, r3, 1		addi r3, r3, 1
	swi r3, r12, 0x400 + TOPHYS(r0_ram)		swi r3, r12, 0x400 + r0_ram

			# Find and jump into the syscall handler.
			lwi r12, r12, sys_call_table
			/* where the trap should return need -8 to adjust for rtsd r15, 8 */
			la r15, r0, ret_from_trap-8
			bra r12

	lwi r12, r12, TOPHYS(sys_call_table); /* Function ptr */
	/* Make the system call. to r12*/
	set_vms;
	rtid r12, 0;
	nop;
	/* The syscall number is invalid, return an error. */		/* The syscall number is invalid, return an error. */
	1: VM_ON; /* RETURN() expects virtual mode*/		5:
	addi r3, r0, -ENOSYS;		addi r3, r0, -ENOSYS;
	rtsd r15,8; /* looks like a normal subroutine return */		rtsd r15,8; /* looks like a normal subroutine return */
	or r0, r0, r0		or r0, r0, r0


	/* Entry point used to return from a syscall/trap. */		/* Entry point used to return from a syscall/trap */
	/* We re-enable BIP bit before state restore */		/* We re-enable BIP bit before state restore */
	C_ENTRY(ret_from_trap):		C_ENTRY(ret_from_trap):
	set_bip; /* Ints masked for state restore*/		set_bip; /* Ints masked for state restore*/
	@@ -347,6 +378,23 @@ C_ENTRY(ret_from_trap):
	/* See if returning to kernel mode, if so, skip resched &c. */		/* See if returning to kernel mode, if so, skip resched &c. */
	bnei r11, 2f;		bnei r11, 2f;

			/* We're returning to user mode, so check for various conditions that
			* trigger rescheduling. */
			# FIXME: Restructure all these flag checks.
			add r11, r0, CURRENT_TASK; /* Get current task ptr into r11 */
			lwi r11, r11, TS_THREAD_INFO; /* get thread info */
			lwi r11, r11, TI_FLAGS; /* get flags in thread info */
			andi r11, r11, _TIF_WORK_SYSCALL_MASK
			beqi r11, 1f

			swi r3, r1, PTO + PT_R3
			swi r4, r1, PTO + PT_R4
			brlid r15, do_syscall_trace_leave
			addik r5, r1, PTO + PT_R0
			lwi r3, r1, PTO + PT_R3
			lwi r4, r1, PTO + PT_R4
			1:

	/* We're returning to user mode, so check for various conditions that		/* We're returning to user mode, so check for various conditions that
	* trigger rescheduling. */		* trigger rescheduling. */
	/* Get current task ptr into r11 */		/* Get current task ptr into r11 */

arch/microblaze/kernel/ptrace.c

+62 −0

Original line number	Original line	Diff line number	Diff line
	@@ -29,6 +29,10 @@
	#include <linux/sched.h>		#include <linux/sched.h>
	#include <linux/ptrace.h>		#include <linux/ptrace.h>
	#include <linux/signal.h>		#include <linux/signal.h>
			#include <linux/elf.h>
			#include <linux/audit.h>
			#include <linux/seccomp.h>
			#include <linux/tracehook.h>

	#include <linux/errno.h>		#include <linux/errno.h>
	#include <asm/processor.h>		#include <asm/processor.h>
	@@ -174,6 +178,64 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
	return rval;		return rval;
	}		}

			asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
			{
			long ret = 0;

			secure_computing(regs->r12);

			if (test_thread_flag(TIF_SYSCALL_TRACE) &&
			tracehook_report_syscall_entry(regs))
			/*
			* Tracing decided this syscall should not happen.
			* We'll return a bogus call number to get an ENOSYS
			* error, but leave the original number in regs->regs[0].
			*/
			ret = -1L;

			if (unlikely(current->audit_context))
			audit_syscall_entry(EM_XILINX_MICROBLAZE, regs->r12,
			regs->r5, regs->r6,
			regs->r7, regs->r8);

			return ret ?: regs->r12;
			}

			asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
			{
			int step;

			if (unlikely(current->audit_context))
			audit_syscall_exit(AUDITSC_RESULT(regs->r3), regs->r3);

			step = test_thread_flag(TIF_SINGLESTEP);
			if (step \|\| test_thread_flag(TIF_SYSCALL_TRACE))
			tracehook_report_syscall_exit(regs, step);
			}

			#if 0
			static asmlinkage void syscall_trace(void)
			{
			if (!test_thread_flag(TIF_SYSCALL_TRACE))
			return;
			if (!(current->ptrace & PT_PTRACED))
			return;
			/* 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;
			}
			}
			#endif

	void ptrace_disable(struct task_struct *child)		void ptrace_disable(struct task_struct *child)
	{		{
	/* nothing to do */		/* nothing to do */