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Limit FSAReadFileWithPos calls to 1 MiB

This commit is contained in:
Maschell 2023-11-17 10:29:49 +01:00
parent c965730690
commit 6be62dee19
1 changed files with 41 additions and 46 deletions
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87
source/romfs_dev.cpp
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@ -7,6 +7,7 @@
#include <malloc.h>
#include <string.h>
#include <sys/iosupport.h>
#include <sys/param.h>
#include <unistd.h>
#include "romfs_dev.h"
@ -56,74 +57,68 @@ static romfs_file *romFS_file(romfs_mount *mount, uint32_t off) {
return curFile;
}
static ssize_t _romfs_read(romfs_mount *mount, uint64_t offset, void *buffer, uint64_t size) {
if (size == 0) {
static ssize_t _romfs_read(romfs_mount *mount, uint64_t readOffset, void *buffer, uint64_t readSize) {
if (readSize == 0) {
return 0;
}
uint64_t pos = mount->offset + offset;
uint64_t pos = mount->offset + readOffset;
if (mount->fd_type == RomfsSource_FileDescriptor) {
off_t seek_offset = lseek(mount->fd, pos, SEEK_SET);
if (seek_offset < 0 || (off_t) pos != seek_offset) {
return -1;
}
return read(mount->fd, buffer, size);
return read(mount->fd, buffer, readSize);
} else if (mount->fd_type == RomfsSource_FileDescriptor_CafeOS) {
FSError status;
uint32_t bytesRead = 0;
__attribute__((aligned(0x40))) uint8_t alignedBuffer[0x40];
uint64_t len = readSize;
void *ptr = buffer;
while (bytesRead < len) {
// only use input buffer if cache-aligned and read size is a multiple of cache line size
// otherwise read into alignedBuffer
uint8_t *tmp = (uint8_t *) ptr;
size_t size = len - bytesRead;
uint32_t ptrAligned = ((uint32_t) buffer + 0x3F) & ~(0x3F);
uint32_t lenToAlignedPtr = ptrAligned - (uint32_t) buffer;
uint32_t headLen = lenToAlignedPtr > size ? size : lenToAlignedPtr;
uint32_t remainingLen = size;
if (size < 0x40) {
// read partial cache-line back-end
tmp = alignedBuffer;
} else if ((uintptr_t) ptr & 0x3F) {
// read partial cache-line front-end
tmp = alignedBuffer;
size = MIN(size, 0x40 - ((uintptr_t) ptr & 0x3F));
} else {
// read whole cache lines
size &= ~0x3F;
}
// Limit each request to 1 MiB
if (size > 0x100000) {
size = 0x100000;
}
status = FSAReadFileWithPos(mount->cafe_client, tmp, 1, size, pos, mount->cafe_fd, 0);
// read "head
if (headLen > 0) {
status = FSAReadFileWithPos(mount->cafe_client, alignedBuffer, 1, headLen, pos, mount->cafe_fd, 0);
if (status < 0) {
if (bytesRead != 0) {
return bytesRead; // error after partial read
}
return -1;
} else if (status > 0) {
memcpy(buffer, alignedBuffer, (uint32_t) status);
bytesRead += (uint32_t) status;
pos += (uint32_t) status;
buffer = (void *) ((uint32_t) buffer + status);
remainingLen -= status;
}
// Return when we've read partial data or finished reading all data
if ((uint32_t) status < headLen || remainingLen == 0) {
return bytesRead;
}
}
uint32_t bodyLen = remainingLen & ~(0x3F);
// read "body"
if (bodyLen > 0) {
status = FSAReadFileWithPos(mount->cafe_client, (uint8_t *) buffer, 1, bodyLen, pos, mount->cafe_fd, 0);
if (status < 0) {
return -1;
} else if (status > 0) {
bytesRead += (uint32_t) status;
buffer = (void *) ((uint32_t) buffer + status);
pos += status;
remainingLen -= status;
if (tmp == alignedBuffer) {
memcpy(ptr, alignedBuffer, status);
}
// Return when we've read partial data or finished reading all data
if ((uint32_t) status < bodyLen || remainingLen == 0) {
return bytesRead;
}
}
// read "tail"
status = FSAReadFileWithPos(mount->cafe_client, alignedBuffer, 1, remainingLen, pos, mount->cafe_fd, 0);
if (status < 0) {
return -1;
} else if (status > 0) {
memcpy(buffer, alignedBuffer, (uint32_t) status);
pos += (uint32_t) status;
bytesRead += (uint32_t) status;
ptr = (void *) (((uint32_t) ptr) + status);
if ((size_t) status != size) {
return bytesRead; // partial read
}
}
return bytesRead;