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authorSebastian Siewior <bigeasy@linutronix.de>2008-10-12 23:15:26 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2008-10-21 15:17:47 +1100
commitc10c178a92b032ea3dd7259dcbbd1b9331c05c41 (patch)
treed539b62ebf4f6821f7b4b2159982ba1214c30d68
parentc1075fb7ec62b7ac0ac6baee2ceeb77270206aef (diff)
powerpc/boot: Compare _start against ei.loadsize instead ei.memsize
If the vmlinux binary in memory is larger than 4 MiB than it collides with the initial boot code which is linked at 4 MiB in case of cuBoot. If the the uncompressed image size (on disk size) is less than 4 MiB then it would fit. The difference between those two sizes is the bss section. In cuBoot we have the dtb embedded right after the data section so it is very likely that the reset of the bss section (in kernel's start up code) will overwrite the dtb blob. Therefore we reallocate the dtb. Something similar is allready done to the initrd. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
-rw-r--r--arch/powerpc/boot/libfdt-wrapper.c16
-rw-r--r--arch/powerpc/boot/main.c14
2 files changed, 20 insertions, 10 deletions
diff --git a/arch/powerpc/boot/libfdt-wrapper.c b/arch/powerpc/boot/libfdt-wrapper.c
index c541fd8a95d..1daa73f08ba 100644
--- a/arch/powerpc/boot/libfdt-wrapper.c
+++ b/arch/powerpc/boot/libfdt-wrapper.c
@@ -165,6 +165,7 @@ static unsigned long fdt_wrapper_finalize(void)
void fdt_init(void *blob)
{
int err;
+ int bufsize;
dt_ops.finddevice = fdt_wrapper_finddevice;
dt_ops.getprop = fdt_wrapper_getprop;
@@ -178,16 +179,15 @@ void fdt_init(void *blob)
/* Make sure the dt blob is the right version and so forth */
fdt = blob;
- err = fdt_open_into(fdt, fdt, fdt_totalsize(blob));
- if (err == -FDT_ERR_NOSPACE) {
- int bufsize = fdt_totalsize(fdt) + 4;
- buf = malloc(bufsize);
- err = fdt_open_into(fdt, buf, bufsize);
- }
+ bufsize = fdt_totalsize(fdt) + 4;
+ buf = malloc(bufsize);
+ if(!buf)
+ fatal("malloc failed. can't relocate the device tree\n\r");
+
+ err = fdt_open_into(fdt, buf, bufsize);
if (err != 0)
fatal("fdt_init(): %s\n\r", fdt_strerror(err));
- if (buf)
- fdt = buf;
+ fdt = buf;
}
diff --git a/arch/powerpc/boot/main.c b/arch/powerpc/boot/main.c
index 9e7f3ddd991..ae32801ebd6 100644
--- a/arch/powerpc/boot/main.c
+++ b/arch/powerpc/boot/main.c
@@ -56,9 +56,19 @@ static struct addr_range prep_kernel(void)
if (platform_ops.vmlinux_alloc) {
addr = platform_ops.vmlinux_alloc(ei.memsize);
} else {
- if ((unsigned long)_start < ei.memsize)
+ /*
+ * Check if the kernel image (without bss) would overwrite the
+ * bootwrapper. The device tree has been moved in fdt_init()
+ * to an area allocated with malloc() (somewhere past _end).
+ */
+ if ((unsigned long)_start < ei.loadsize)
fatal("Insufficient memory for kernel at address 0!"
- " (_start=%p)\n\r", _start);
+ " (_start=%p, uncomressed size=%08x)\n\r",
+ _start, ei.loadsize);
+
+ if ((unsigned long)_end < ei.memsize)
+ fatal("The final kernel image would overwrite the "
+ "device tree\n\r");
}
/* Finally, gunzip the kernel */