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Luma3DS-3GX/sysmodules/rosalina/source/gdb/watchpoints.c

152 lines
4.2 KiB
C

/*
* This file is part of Luma3DS.
* Copyright (C) 2016-2019 Aurora Wright, TuxSH
*
* SPDX-License-Identifier: (MIT OR GPL-2.0-or-later)
*/
#include "gdb/watchpoints.h"
#include "csvc.h"
#define _REENT_ONLY
#include <errno.h>
/*
There are only 2 Watchpoint Register Pairs on MPCORE ARM11 CPUs,
and only 2 Breakpoint Register Pairs with context ID capabilities (BRP4-5) as well.
We'll reserve and use all 4 of them
*/
RecursiveLock watchpointManagerLock;
typedef struct Watchpoint
{
u32 address;
u32 size;
WatchpointKind kind;
Handle debug; // => context ID
} Watchpoint;
typedef struct WatchpointManager
{
u32 total;
Watchpoint watchpoints[2];
} WatchpointManager;
static WatchpointManager manager;
void GDB_ResetWatchpoints(void)
{
static bool lockInitialized = false;
if(!lockInitialized)
{
RecursiveLock_Init(&watchpointManagerLock);
lockInitialized = true;
}
RecursiveLock_Lock(&watchpointManagerLock);
svcKernelSetState(0x10003); // enable monitor mode debugging
svcKernelSetState(0x10004, 0); // disable watchpoint 0
svcKernelSetState(0x10004, 1); // disable watchpoint 1
memset(&manager, 0, sizeof(WatchpointManager));
RecursiveLock_Unlock(&watchpointManagerLock);
}
int GDB_AddWatchpoint(GDBContext *ctx, u32 address, u32 size, WatchpointKind kind)
{
RecursiveLock_Lock(&watchpointManagerLock);
u32 offset = address - (address & ~3);
if(manager.total == 2)
return -EBUSY;
if(size == 0 || (offset + size) > 4 || kind == WATCHPOINT_DISABLED)
return -EINVAL;
if(GDB_GetWatchpointKind(ctx, address) != WATCHPOINT_DISABLED)
// Disallow duplicate watchpoints: the kernel doesn't give us sufficient info to differentiate them by kind (DFSR)
return -EINVAL;
u32 id = manager.watchpoints[0].kind == WATCHPOINT_DISABLED ? 0 : 1;
u32 selectMask = ((1 << size) - 1) << offset;
u32 WCR = (1 << 20) | /* linked */
((4 + id) << 16) | /* ID of the linked BRP */
(selectMask << 5) | /* byte address select */
((u32)kind << 3) | /* kind */
(2 << 1) | /* user mode only */
(1 << 0) ; /* enabled */
s64 out;
Result r = svcGetHandleInfo(&out, ctx->debug, 0x10000); // context ID
if(R_SUCCEEDED(r))
{
svcKernelSetState(id == 0 ? 0x10005 : 0x10006, address, WCR, (u32)out); // set watchpoint
Watchpoint *watchpoint = &manager.watchpoints[id];
manager.total++;
watchpoint->address = address;
watchpoint->size = size;
watchpoint->kind = kind;
watchpoint->debug = ctx->debug;
ctx->watchpoints[ctx->nbWatchpoints++] = address;
RecursiveLock_Unlock(&watchpointManagerLock);
return 0;
}
else
{
RecursiveLock_Unlock(&watchpointManagerLock);
return -EINVAL;
}
}
int GDB_RemoveWatchpoint(GDBContext *ctx, u32 address, WatchpointKind kind)
{
RecursiveLock_Lock(&watchpointManagerLock);
u32 id;
for(id = 0; id < 2 && manager.watchpoints[id].address != address && manager.watchpoints[id].debug != ctx->debug; id++);
if(id == 2 || (kind != WATCHPOINT_DISABLED && manager.watchpoints[id].kind != kind))
{
RecursiveLock_Unlock(&watchpointManagerLock);
return -EINVAL;
}
else
{
svcKernelSetState(0x10004, id); // disable watchpoint
memset(&manager.watchpoints[id], 0, sizeof(Watchpoint));
manager.total--;
if(ctx->watchpoints[0] == address)
{
ctx->watchpoints[0] = ctx->watchpoints[1];
ctx->watchpoints[1] = 0;
ctx->nbWatchpoints--;
}
else if(ctx->watchpoints[1] == address)
{
ctx->watchpoints[1] = 0;
ctx->nbWatchpoints--;
}
RecursiveLock_Unlock(&watchpointManagerLock);
return 0;
}
}
WatchpointKind GDB_GetWatchpointKind(GDBContext *ctx, u32 address)
{
u32 id;
for(id = 0; id < 2 && (manager.watchpoints[id].address != address || manager.watchpoints[id].debug != ctx->debug); id++);
return id == 2 ? WATCHPOINT_DISABLED : manager.watchpoints[id].kind;
}