On Mon, Jan 07, 2019 at 07:21:20PM +0800, Miles Chen wrote: > Current __virt_to_phys() only print warning messages for non-linear > addresses. It's hard to catch all warnings by those messages.
Why? Are you seeing a large number of warnings somewhere? > So add a VIRTUAL_BUG_ON() to trap all non-linear and non-symbol > addresses (e.g., stack addresses) > > Tested by pass stack addresses and symbol addresses to __pa(). Result: > stack addresses: kernel BUG() Either: * Stacks are vmap'd, and __is_lm_address(stack_addr) is false. We'll produce a WARNING() today (and return a junk physical address). * Stacks are linear mapped, and cannot be distinguished from other linear mapped addresses. The physical address will be valid. ... so I don't understand why you need to change this. > symbol addresses: kernel warning message That should already be the case today, since the kernel image is mapped separately from the linear map, so __is_lm_address(symbol_addr) should be false. > > Maybe we should trap all non-linear address translations in the future. > > Signed-off-by: Miles Chen <miles.c...@mediatek.com> > --- > arch/arm64/mm/physaddr.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/arch/arm64/mm/physaddr.c b/arch/arm64/mm/physaddr.c > index 67a9ba9eaa96..f6b935dad19c 100644 > --- a/arch/arm64/mm/physaddr.c > +++ b/arch/arm64/mm/physaddr.c > @@ -14,6 +14,11 @@ phys_addr_t __virt_to_phys(unsigned long x) > (void *)x, > (void *)x); > > + /* trap all non-linear and non-symbol addresses */ > + VIRTUAL_BUG_ON(!__is_lm_address(x) && > + (x < (unsigned long)KERNEL_START || > + x > (unsigned long)KERNEL_END)); The KERNEL_START and KERNEL_END definitions refer to the kernel image, not the linear map, so it doesn't make any sense to permit those here. It is *not* valid to call __virt_to_phys() with a symbol address. We only support those in __virt_to_phys_nodebug() so that broken code has a chance of stumbling on. If you want the kernel to die immediately when it hits a warning here, please set panic_on_warn. Thanks, Mark.
