80486DX2-66/86Box-fork
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Fixed a very bad flaw in mem.c which was causing lookup arrays for memory above 1 MB but below 2 MB to point to a bogus area of memory, also fixes 64-bit 86Box.

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OBattler
2020-07-15 23:22:26 +02:00
parent 4cd6ffa5fd
commit a4afacfe0e
1 changed files with 26 additions and 10 deletions
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36
src/mem/mem.c
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@@ -80,7 +80,8 @@ page_t *pages, /* RAM page table */
**page_lookup; /* pagetable lookup */
uint32_t pages_sz; /* #pages in table */
uint8_t *ram, *ram2; /* the virtual RAM */
uint8_t *low_ram,
*ram, *ram2; /* the virtual RAM */
uint8_t page_ff[4096];
uint32_t rammask;
@@ -588,10 +589,12 @@ addreadlookup(uint32_t virt, uint32_t phys)
if (readlookup[readlnext] != (int) 0xffffffff)
readlookup2[readlookup[readlnext]] = LOOKUP_INV;
a = (uintptr_t)(phys & ~0xfff) - (uintptr_t)(virt & ~0xfff);
a = (uint32_t)(phys & ~0xfff) - (uint32_t)(virt & ~0xfff);
if ((phys & ~0xfff) >= (1 << 30))
readlookup2[virt>>12] = (uintptr_t)&ram2[a - (1 << 30)];
else if (a >= 0xfff00000)
readlookup2[virt>>12] = (uintptr_t)&low_ram[a & 0x000fffff];
else
readlookup2[virt>>12] = (uintptr_t)&ram[a];
@@ -632,10 +635,12 @@ addwritelookup(uint32_t virt, uint32_t phys)
#endif
page_lookup[virt >> 12] = &pages[phys >> 12];
else {
a = (uintptr_t)(phys & ~0xfff) - (uintptr_t)(virt & ~0xfff);
a = (uint32_t)(phys & ~0xfff) - (uint32_t)(virt & ~0xfff);
if ((phys & ~0xfff) >= (1 << 30))
writelookup2[virt>>12] = (uintptr_t)&ram2[a - (1 << 30)];
else if (a >= 0xfff00000)
writelookup2[virt>>12] = (uintptr_t)&low_ram[a & 0x000fffff];
else
writelookup2[virt>>12] = (uintptr_t)&ram[a];
}
@@ -2526,26 +2531,36 @@ mem_reset(void)
memset(page_ff, 0xff, sizeof(page_ff));
m = 1024UL * mem_size;
if (ram != NULL) {
free(ram);
ram = NULL;
if (low_ram != NULL) {
free(low_ram);
low_ram = NULL;
}
#if (defined __amd64__ || defined _M_X64)
if (ram2 != NULL) {
free(ram2);
ram2 = NULL;
}
#endif
if (mem_size > 2097152)
fatal("Attempting to use more than 2 GB of guest RAM\n");
#if (defined __amd64__ || defined _M_X64)
if (mem_size > 1048576) {
ram = (uint8_t *)malloc(1 << 30); /* allocate and clear the RAM block of the first 1 GB */
memset(ram, 0x00, 1 << 30);
low_ram = (uint8_t *)malloc((1 << 30) + (1 << 10)); /* allocate and clear the RAM block of the first 1 GB */
memset(low_ram, 0x00, (1 << 30) + (1 << 10));
ram2 = (uint8_t *)malloc(m - (1 << 30)); /* allocate and clear the RAM block above 1 GB */
memset(ram2, 0x00, m - (1 << 30));
} else {
ram = (uint8_t *)malloc(m); /* allocate and clear the RAM block */
memset(ram, 0x00, m);
low_ram = (uint8_t *)malloc(m + (1 << 10)); /* allocate and clear the RAM block */
memset(low_ram, 0x00, m + (1 << 10));
}
#else
low_ram = (uint8_t *)malloc(m + (1 << 10)); /* allocate and clear the RAM block */
memset(low_ram, 0x00, m + (1 << 10));
if (mem_size > 1048576)
ram2 = &(low_ram[(1 << 30) + (1 << 10)]);
#endif
ram = &(low_ram[1 << 10]);
/*
* Allocate the page table based on how much RAM we have.
@@ -2758,6 +2773,7 @@ void
mem_init(void)
{
/* Perform a one-time init. */
low_ram = NULL;
ram = rom = NULL;
ram2 = NULL;
pages = NULL;