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authorSerge Semin <fancer.lancer@gmail.com>2019-05-03 19:50:40 +0200
committerPaul Burton <paul.burton@mips.com>2019-05-06 05:11:59 +0200
commit93fa5b280761a4dbb14c5330f260380385ab2b49 (patch)
tree8df23f64c96aa3843caaac462607694c97a5603e /arch/mips/kernel/prom.c
parentmips: Perform early low memory test (diff)
downloadlinux-93fa5b280761a4dbb14c5330f260380385ab2b49.tar.xz
linux-93fa5b280761a4dbb14c5330f260380385ab2b49.zip
mips: Make sure dt memory regions are valid
There are situations when memory regions coming from dts may be too big for the platform physical address space. This especially concerns XPA-capable systems. Bootloader may determine more than 4GB memory available and pass it to the kernel over dts memory node, while kernel is built without XPA/64BIT support. In this case the region may either simply be truncated by add_memory_region() method or by u64->phys_addr_t type casting. But in worst case the method can even drop the memory region if it exceeds PHYS_ADDR_MAX size. So lets make sure the retrieved from dts memory regions are valid, and if some of them aren't, just manually truncate them with a warning printed out. Signed-off-by: Serge Semin <fancer.lancer@gmail.com> Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: James Hogan <jhogan@kernel.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Thomas Bogendoerfer <tbogendoerfer@suse.de> Cc: Huacai Chen <chenhc@lemote.com> Cc: Stefan Agner <stefan@agner.ch> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com> Cc: Juergen Gross <jgross@suse.com> Cc: Serge Semin <Sergey.Semin@t-platforms.ru> Cc: linux-mips@vger.kernel.org Cc: linux-kernel@vger.kernel.org
Diffstat (limited to 'arch/mips/kernel/prom.c')
-rw-r--r--arch/mips/kernel/prom.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/arch/mips/kernel/prom.c b/arch/mips/kernel/prom.c
index 437a174e3ef9..28bf01961bb2 100644
--- a/arch/mips/kernel/prom.c
+++ b/arch/mips/kernel/prom.c
@@ -41,7 +41,19 @@ char *mips_get_machine_name(void)
#ifdef CONFIG_USE_OF
void __init early_init_dt_add_memory_arch(u64 base, u64 size)
{
- return add_memory_region(base, size, BOOT_MEM_RAM);
+ if (base >= PHYS_ADDR_MAX) {
+ pr_warn("Trying to add an invalid memory region, skipped\n");
+ return;
+ }
+
+ /* Truncate the passed memory region instead of type casting */
+ if (base + size - 1 >= PHYS_ADDR_MAX || base + size < base) {
+ pr_warn("Truncate memory region %llx @ %llx to size %llx\n",
+ size, base, PHYS_ADDR_MAX - base);
+ size = PHYS_ADDR_MAX - base;
+ }
+
+ add_memory_region(base, size, BOOT_MEM_RAM);
}
int __init early_init_dt_reserve_memory_arch(phys_addr_t base,