| Message ID | 20190503175041.7949-5-fancer.lancer@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | mips: Post-bootmem-memblock transition fixes | expand |
Hello, Serge Semin wrote: > 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> Applied to mips-next. Thanks, Paul [ This message was auto-generated; if you believe anything is incorrect then please email paul.burton@mips.com to report it. ]
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,
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> --- arch/mips/kernel/prom.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)