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| author |   Serge Semin <fancer.lancer@gmail.com> | 2019-05-03 20:50:40 +0300 |
|---|---|---|
| committer |   Paul Burton <paul.burton@mips.com> | 2019-05-05 20:11:59 -0700 |
| commit | 93fa5b280761a4dbb14c5330f260380385ab2b49 (patch) | |
| tree | 8df23f64c96aa3843caaac462607694c97a5603e /arch/mips | |
| parent | mips: Perform early low memory test (diff) | |
| download | linux-dev-93fa5b280761a4dbb14c5330f260380385ab2b49.tar.xz linux-dev-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')
| -rw-r--r-- | arch/mips/kernel/prom.c | 14 |
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, |