search for: probe_rom

Hi Mike, On Tue, Jul 21, 2020 at 09:01:44PM +0000, Mike Stunes wrote: > I?m running into an MMIO-related bug when I try testing this on our hypervisor. > > During boot, probe_roms (arch/x86/kernel/probe_roms.c) uses > romchecksum over the video ROM and extension ROM regions. In my test > VM, the video ROM romchecksum starts at virtual address > 0xffff8880000c0000 and has length 65536. But, at address > 0xffff8880000c4000, we switch from being video-ROM-backed to...

Hmm, I have a theory ... On Tue, Jul 21, 2020 at 09:01:44PM +0000, Mike Stunes wrote: > If I remove the call to probe_roms from setup_arch, or remove the calls to romchecksum from probe_roms, this kernel boots normally. > > Please let me know of other tests I should run or data that I can collect. Thanks! ... can you please try the attached diff? diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es....

I'm seeing oopses in probe_roms() and pci_find_bios(), apparently because those pages are not mapped under Xen. I'm not sure why I'm seeing this now and not before, but I suspect its because I enabled CONFIG_DEBUG_PAGEALLOC. Anyway, I've got these patches to deal with these cases: --- a/arch/i386/kernel/setup....

I'm seeing oopses in probe_roms() and pci_find_bios(), apparently because those pages are not mapped under Xen. I'm not sure why I'm seeing this now and not before, but I suspect its because I enabled CONFIG_DEBUG_PAGEALLOC. Anyway, I've got these patches to deal with these cases: --- a/arch/i386/kernel/setup....

...+= traps.o irq.o irq_$(BITS).o dumpstack_$(BITS).o -obj-y += time.o ioport.o ldt.o dumpstack.o nmi.o +obj-y += time.o ldt.o dumpstack.o nmi.o +obj-$(CONFIG_X86_IOPORT) += ioport.o obj-y += setup.o x86_init.o i8259.o irqinit.o jump_label.o obj-$(CONFIG_IRQ_WORK) += irq_work.o obj-y += probe_roms.o diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index df088bb..1e6a74e0 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -609,6 +609,11 @@ ENTRY(stub_\func) END(stub_\func) .endm + FORK_LIKE clone + FORK_LIKE fork + FORK_LIKE vfork + +#ifde...

...+= traps.o irq.o irq_$(BITS).o dumpstack_$(BITS).o -obj-y += time.o ioport.o ldt.o dumpstack.o nmi.o +obj-y += time.o ldt.o dumpstack.o nmi.o +obj-$(CONFIG_X86_IOPORT) += ioport.o obj-y += setup.o x86_init.o i8259.o irqinit.o jump_label.o obj-$(CONFIG_IRQ_WORK) += irq_work.o obj-y += probe_roms.o diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index df088bb..1e6a74e0 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -609,6 +609,11 @@ ENTRY(stub_\func) END(stub_\func) .endm + FORK_LIKE clone + FORK_LIKE fork + FORK_LIKE vfork + +#ifde...

...+= traps.o irq.o irq_$(BITS).o dumpstack_$(BITS).o -obj-y += time.o ioport.o ldt.o dumpstack.o nmi.o +obj-y += time.o ldt.o dumpstack.o nmi.o +obj-$(CONFIG_X86_IOPORT) += ioport.o obj-y += setup.o x86_init.o i8259.o irqinit.o jump_label.o obj-$(CONFIG_IRQ_WORK) += irq_work.o obj-y += probe_roms.o diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 2793d1f..01235ef 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1223,7 +1223,6 @@ void cpu_init(void) struct tss_struct *t; unsigned long v; int cpu; - int i; /* * Load m...

...+= traps.o irq.o irq_$(BITS).o dumpstack_$(BITS).o -obj-y += time.o ioport.o ldt.o dumpstack.o nmi.o +obj-y += time.o ldt.o dumpstack.o nmi.o +obj-$(CONFIG_X86_IOPORT) += ioport.o obj-y += setup.o x86_init.o i8259.o irqinit.o jump_label.o obj-$(CONFIG_IRQ_WORK) += irq_work.o obj-y += probe_roms.o diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 8e28bf2..de79215 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1236,7 +1236,6 @@ void cpu_init(void) struct tss_struct *t; unsigned long v; int cpu; - int i; /* * Load m...

....o ioport.o ldt.o dumpstack.o nmi.o > +obj-y += time.o ldt.o dumpstack.o nmi.o > +obj-$(CONFIG_X86_IOPORT) += ioport.o > obj-y += setup.o x86_init.o i8259.o irqinit.o jump_label.o > obj-$(CONFIG_IRQ_WORK) += irq_work.o > obj-y += probe_roms.o > diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c > index 2793d1f..01235ef 100644 > --- a/arch/x86/kernel/cpu/common.c > +++ b/arch/x86/kernel/cpu/common.c > @@ -1223,7 +1223,6 @@ void cpu_init(void) > struct tss_struct *t; > unsigned...

....o ioport.o ldt.o dumpstack.o nmi.o > +obj-y += time.o ldt.o dumpstack.o nmi.o > +obj-$(CONFIG_X86_IOPORT) += ioport.o > obj-y += setup.o x86_init.o i8259.o irqinit.o jump_label.o > obj-$(CONFIG_IRQ_WORK) += irq_work.o > obj-y += probe_roms.o > diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c > index 2793d1f..01235ef 100644 > --- a/arch/x86/kernel/cpu/common.c > +++ b/arch/x86/kernel/cpu/common.c > @@ -1223,7 +1223,6 @@ void cpu_init(void) > struct tss_struct *t; > unsigned...

The 32-bit and 64-bit versions of copy_thread have functionally identical handling for copying the I/O bitmap, modulo differences in error handling. Clean up the error paths in both by moving the copy of the I/O bitmap to the end, to eliminate the need to free it if subsequent copy steps fail; move the resulting identical code to a static inline in a common header. Signed-off-by: Josh Triplett

The 32-bit and 64-bit versions of copy_thread have functionally identical handling for copying the I/O bitmap, modulo differences in error handling. Clean up the error paths in both by moving the copy of the I/O bitmap to the end, to eliminate the need to free it if subsequent copy steps fail; move the resulting identical code to a static inline in a common header. Signed-off-by: Josh Triplett

....o ioport.o ldt.o dumpstack.o nmi.o > +obj-y += time.o ldt.o dumpstack.o nmi.o > +obj-$(CONFIG_X86_IOPORT) += ioport.o > obj-y += setup.o x86_init.o i8259.o irqinit.o jump_label.o > obj-$(CONFIG_IRQ_WORK) += irq_work.o > obj-y += probe_roms.o > diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c > index 4b4f78c..ae2e8d7 100644 > --- a/arch/x86/kernel/cpu/common.c > +++ b/arch/x86/kernel/cpu/common.c > @@ -1297,7 +1297,6 @@ void cpu_init(void) > struct tss_struct *t; > unsigned...

This patch series makes it possible to compile out the iopl and ioperm system calls, which allow privileged processes to request permission to directly poke I/O ports from userspace. Nothing on a modern Linux system uses these calls anymore, and anything new should be using /dev/port instead, or better yet writing a driver. Copying the bloat-o-meter stats from the final patch: 32-bit

This patch series makes it possible to compile out the iopl and ioperm system calls, which allow privileged processes to request permission to directly poke I/O ports from userspace. Nothing on a modern Linux system uses these calls anymore, and anything new should be using /dev/port instead, or better yet writing a driver. Copying the bloat-o-meter stats from the final patch: 32-bit

...+= traps.o irq.o irq_$(BITS).o dumpstack_$(BITS).o -obj-y += time.o ioport.o ldt.o dumpstack.o nmi.o +obj-y += time.o ldt.o dumpstack.o nmi.o +obj-$(CONFIG_X86_IOPORT) += ioport.o obj-y += setup.o x86_init.o i8259.o irqinit.o jump_label.o obj-$(CONFIG_IRQ_WORK) += irq_work.o obj-y += probe_roms.o diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 4b4f78c..ae2e8d7 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1297,7 +1297,6 @@ void cpu_init(void) struct tss_struct *t; unsigned long v; int cpu = stack_smp_processor_id();...

...+= traps.o irq.o irq_$(BITS).o dumpstack_$(BITS).o -obj-y += time.o ioport.o ldt.o dumpstack.o nmi.o +obj-y += time.o ldt.o dumpstack.o nmi.o +obj-$(CONFIG_X86_IOPORT) += ioport.o obj-y += setup.o x86_init.o i8259.o irqinit.o jump_label.o obj-$(CONFIG_IRQ_WORK) += irq_work.o obj-y += probe_roms.o diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 4b4f78c..ae2e8d7 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1297,7 +1297,6 @@ void cpu_init(void) struct tss_struct *t; unsigned long v; int cpu = stack_smp_processor_id();...

...).o dumpstack_$(BITS).o > -obj-y += time.o ioport.o ldt.o dumpstack.o nmi.o > +obj-y += time.o ldt.o dumpstack.o nmi.o > +obj-$(CONFIG_X86_IOPORT) += ioport.o > obj-y += setup.o x86_init.o i8259.o irqinit.o jump_label.o > obj-$(CONFIG_IRQ_WORK) += irq_work.o > obj-y += probe_roms.o > diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c > index 2793d1f..01235ef 100644 > --- a/arch/x86/kernel/cpu/common.c > +++ b/arch/x86/kernel/cpu/common.c > @@ -1223,7 +1223,6 @@ void cpu_init(void) > struct tss_struct *t; > unsigned long v; &gt...

...).o dumpstack_$(BITS).o > -obj-y += time.o ioport.o ldt.o dumpstack.o nmi.o > +obj-y += time.o ldt.o dumpstack.o nmi.o > +obj-$(CONFIG_X86_IOPORT) += ioport.o > obj-y += setup.o x86_init.o i8259.o irqinit.o jump_label.o > obj-$(CONFIG_IRQ_WORK) += irq_work.o > obj-y += probe_roms.o > diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c > index 2793d1f..01235ef 100644 > --- a/arch/x86/kernel/cpu/common.c > +++ b/arch/x86/kernel/cpu/common.c > @@ -1223,7 +1223,6 @@ void cpu_init(void) > struct tss_struct *t; > unsigned long v; &gt...

The 32-bit and 64-bit versions of copy_thread have functionally identical handling for copying the I/O bitmap, modulo differences in error handling. Clean up the error paths in both by moving the copy of the I/O bitmap to the end, to eliminate the need to free it if subsequent copy steps fail; move the resulting identical code to a static inline in a common header. Signed-off-by: Josh Triplett