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acpi-build: don't access unaligned addresses

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casting an unaligned address to e.g.
uint32_t can trigger undefined behaviour in C.
Replace cast + assignment with memcpy.

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2014-03-10 21:30:16 +02:00
parent 263cf4367f
commit b4e5a4bffd
1 changed files with 16 additions and 15 deletions
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31
hw/i386/acpi-build.c
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@ -466,9 +466,15 @@ static void acpi_align_size(GArray *blob, unsigned align)
g_array_set_size(blob, ROUND_UP(acpi_data_len(blob), align));
}
/* Get pointer within table in a safe manner */
#define ACPI_BUILD_PTR(table, size, off, type) \
((type *)(acpi_data_get_ptr(table, size, off, sizeof(type))))
/* Set a value within table in a safe manner */
#define ACPI_BUILD_SET_LE(table, size, off, bits, val) \
do { \
uint64_t ACPI_BUILD_SET_LE_val = cpu_to_le64(val); \
memcpy(acpi_data_get_ptr(table, size, off, \
(bits) / BITS_PER_BYTE), \
&ACPI_BUILD_SET_LE_val, \
(bits) / BITS_PER_BYTE); \
} while (0)
static inline void *acpi_data_get_ptr(uint8_t *table_data, unsigned table_size,
unsigned off, unsigned size)
@ -974,22 +980,17 @@ static void build_pci_bus_end(PCIBus *bus, void *bus_state)
static void patch_pci_windows(PcPciInfo *pci, uint8_t *start, unsigned size)
{
*ACPI_BUILD_PTR(start, size, acpi_pci32_start[0], uint32_t) =
cpu_to_le32(pci->w32.begin);
ACPI_BUILD_SET_LE(start, size, acpi_pci32_start[0], 32, pci->w32.begin);
*ACPI_BUILD_PTR(start, size, acpi_pci32_end[0], uint32_t) =
cpu_to_le32(pci->w32.end - 1);
ACPI_BUILD_SET_LE(start, size, acpi_pci32_end[0], 32, pci->w32.end - 1);
if (pci->w64.end || pci->w64.begin) {
*ACPI_BUILD_PTR(start, size, acpi_pci64_valid[0], uint8_t) = 1;
*ACPI_BUILD_PTR(start, size, acpi_pci64_start[0], uint64_t) =
cpu_to_le64(pci->w64.begin);
*ACPI_BUILD_PTR(start, size, acpi_pci64_end[0], uint64_t) =
cpu_to_le64(pci->w64.end - 1);
*ACPI_BUILD_PTR(start, size, acpi_pci64_length[0], uint64_t) =
cpu_to_le64(pci->w64.end - pci->w64.begin);
ACPI_BUILD_SET_LE(start, size, acpi_pci64_valid[0], 8, 1);
ACPI_BUILD_SET_LE(start, size, acpi_pci64_start[0], 64, pci->w64.begin);
ACPI_BUILD_SET_LE(start, size, acpi_pci64_end[0], 64, pci->w64.end - 1);
ACPI_BUILD_SET_LE(start, size, acpi_pci64_length[0], 64, pci->w64.end - pci->w64.begin);
} else {
*ACPI_BUILD_PTR(start, size, acpi_pci64_valid[0], uint8_t) = 0;
ACPI_BUILD_SET_LE(start, size, acpi_pci64_valid[0], 8, 0);
}
}