Hi Eugen, On Wed, Nov 19, 2025 at 05:44:19PM +0200, Eugen Hristev wrote: > This memblock flag indicates that a specific block is registered > into an inspection table. > The block can be marked for inspection using memblock_mark_inspect() > and cleared with memblock_clear_inspect()
Can you explain why memblock should treat memory registered for inspection differently? > Signed-off-by: Eugen Hristev <[email protected]> > --- > include/linux/memblock.h | 7 +++++++ > mm/memblock.c | 36 ++++++++++++++++++++++++++++++++++++ > 2 files changed, 43 insertions(+) > > diff --git a/include/linux/memblock.h b/include/linux/memblock.h > index 221118b5a16e..c3e55a4475cf 100644 > --- a/include/linux/memblock.h > +++ b/include/linux/memblock.h > @@ -51,6 +51,10 @@ extern unsigned long long max_possible_pfn; > * memory reservations yet, so we get scratch memory from the previous > * kernel that we know is good to use. It is the only memory that > * allocations may happen from in this phase. > + * @MEMBLOCK_INSPECT: memory region is annotated in kernel memory inspection > + * table. This means a dedicated entry will be created for this region which > + * will contain the memory's address and size. This allows kernel inspectors > + * to retrieve the memory. > */ > enum memblock_flags { > MEMBLOCK_NONE = 0x0, /* No special request */ > @@ -61,6 +65,7 @@ enum memblock_flags { > MEMBLOCK_RSRV_NOINIT = 0x10, /* don't initialize struct pages */ > MEMBLOCK_RSRV_KERN = 0x20, /* memory reserved for kernel use */ > MEMBLOCK_KHO_SCRATCH = 0x40, /* scratch memory for kexec handover */ > + MEMBLOCK_INSPECT = 0x80, /* memory selected for kernel > inspection */ > }; > > /** > @@ -149,6 +154,8 @@ unsigned long memblock_addrs_overlap(phys_addr_t base1, > phys_addr_t size1, > bool memblock_overlaps_region(struct memblock_type *type, > phys_addr_t base, phys_addr_t size); > bool memblock_validate_numa_coverage(unsigned long threshold_bytes); > +int memblock_mark_inspect(phys_addr_t base, phys_addr_t size); > +int memblock_clear_inspect(phys_addr_t base, phys_addr_t size); > int memblock_mark_hotplug(phys_addr_t base, phys_addr_t size); > int memblock_clear_hotplug(phys_addr_t base, phys_addr_t size); > int memblock_mark_mirror(phys_addr_t base, phys_addr_t size); > diff --git a/mm/memblock.c b/mm/memblock.c > index e23e16618e9b..a5df5ab286e5 100644 > --- a/mm/memblock.c > +++ b/mm/memblock.c > @@ -17,6 +17,7 @@ > #include <linux/seq_file.h> > #include <linux/memblock.h> > #include <linux/mutex.h> > +#include <linux/meminspect.h> > > #ifdef CONFIG_KEXEC_HANDOVER > #include <linux/libfdt.h> > @@ -1016,6 +1017,40 @@ static int __init_memblock memblock_setclr_flag(struct > memblock_type *type, > return 0; > } > > +/** > + * memblock_mark_inspect - Mark inspectable memory with flag > MEMBLOCK_INSPECT. > + * @base: the base phys addr of the region > + * @size: the size of the region > + * > + * Return: 0 on success, -errno on failure. > + */ > +int __init_memblock memblock_mark_inspect(phys_addr_t base, phys_addr_t size) > +{ > + int ret; > + > + ret = memblock_setclr_flag(&memblock.memory, base, size, 1, > MEMBLOCK_INSPECT); > + if (ret) > + return ret; > + > + meminspect_lock_register_pa(base, size); > + > + return 0; > +} > + > +/** > + * memblock_clear_inspect - Clear flag MEMBLOCK_INSPECT for a specified > region. > + * @base: the base phys addr of the region > + * @size: the size of the region > + * > + * Return: 0 on success, -errno on failure. > + */ > +int __init_memblock memblock_clear_inspect(phys_addr_t base, phys_addr_t > size) > +{ > + meminspect_lock_unregister_pa(base, size); > + > + return memblock_setclr_flag(&memblock.memory, base, size, 0, > MEMBLOCK_INSPECT); > +} > + > /** > * memblock_mark_hotplug - Mark hotpluggable memory with flag > MEMBLOCK_HOTPLUG. > * @base: the base phys addr of the region > @@ -2704,6 +2739,7 @@ static const char * const flagname[] = { > [ilog2(MEMBLOCK_RSRV_NOINIT)] = "RSV_NIT", > [ilog2(MEMBLOCK_RSRV_KERN)] = "RSV_KERN", > [ilog2(MEMBLOCK_KHO_SCRATCH)] = "KHO_SCRATCH", > + [ilog2(MEMBLOCK_INSPECT)] = "INSPECT", > }; > > static int memblock_debug_show(struct seq_file *m, void *private) > -- > 2.43.0 > -- Sincerely yours, Mike.
