2024-04-19 14:05:29

by Robert Richter

[permalink] [raw]
Subject: [PATCH v3 1/5] x86/numa: Fix SRAT lookup of CFMWS ranges with numa_fill_memblks()

For configurations that have the kconfig option NUMA_KEEP_MEMINFO
disabled, the SRAT lookup done with numa_fill_memblks() fails
returning NUMA_NO_MEMBLK (-1). An existing SRAT memory range cannot be
found for a CFMWS address range. This causes the addition of a
duplicate numa_memblk with a different node id and a subsequent page
fault and kernel crash during boot.

numa_fill_memblks() is implemented and used in the init section only.
The option NUMA_KEEP_MEMINFO is only for the case when NUMA data will
be used outside of init. So fix the SRAT lookup by moving
numa_fill_memblks() out of the NUMA_KEEP_MEMINFO block to make it
always available in the init section.

Note that the issue was initially introduced with [1]. But since
phys_to_target_node() was originally used that returned the valid node
0, an additional numa_memblk was not added. Though, the node id was
wrong too.

[1] commit fd49f99c1809 ("ACPI: NUMA: Add a node and memblk for each
CFMWS not in SRAT")

Fixes: 8f1004679987 ("ACPI/NUMA: Apply SRAT proximity domain to entire CFMWS window")
Cc: Derick Marks <[email protected]>
Cc: Dan Williams <[email protected]>
Cc: Alison Schofield <[email protected]>
Signed-off-by: Robert Richter <[email protected]>
---
arch/x86/include/asm/sparsemem.h | 2 +-
arch/x86/mm/numa.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/sparsemem.h b/arch/x86/include/asm/sparsemem.h
index 1be13b2dfe8b..1aaa447ef24b 100644
--- a/arch/x86/include/asm/sparsemem.h
+++ b/arch/x86/include/asm/sparsemem.h
@@ -37,9 +37,9 @@ extern int phys_to_target_node(phys_addr_t start);
#define phys_to_target_node phys_to_target_node
extern int memory_add_physaddr_to_nid(u64 start);
#define memory_add_physaddr_to_nid memory_add_physaddr_to_nid
+#endif
extern int numa_fill_memblks(u64 start, u64 end);
#define numa_fill_memblks numa_fill_memblks
-#endif
#endif /* __ASSEMBLY__ */

#endif /* _ASM_X86_SPARSEMEM_H */
diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
index 65e9a6e391c0..ce84ba86e69e 100644
--- a/arch/x86/mm/numa.c
+++ b/arch/x86/mm/numa.c
@@ -929,6 +929,8 @@ int memory_add_physaddr_to_nid(u64 start)
}
EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);

+#endif
+
static int __init cmp_memblk(const void *a, const void *b)
{
const struct numa_memblk *ma = *(const struct numa_memblk **)a;
@@ -1001,5 +1003,3 @@ int __init numa_fill_memblks(u64 start, u64 end)
}
return 0;
}
-
-#endif
--
2.39.2



2024-04-22 20:48:30

by Alison Schofield

[permalink] [raw]
Subject: Re: [PATCH v3 1/5] x86/numa: Fix SRAT lookup of CFMWS ranges with numa_fill_memblks()

On Fri, Apr 19, 2024 at 04:01:59PM +0200, Robert Richter wrote:
> For configurations that have the kconfig option NUMA_KEEP_MEMINFO
> disabled, the SRAT lookup done with numa_fill_memblks() fails
> returning NUMA_NO_MEMBLK (-1). An existing SRAT memory range cannot be
> found for a CFMWS address range. This causes the addition of a
> duplicate numa_memblk with a different node id and a subsequent page
> fault and kernel crash during boot.
>
> numa_fill_memblks() is implemented and used in the init section only.
> The option NUMA_KEEP_MEMINFO is only for the case when NUMA data will
> be used outside of init. So fix the SRAT lookup by moving
> numa_fill_memblks() out of the NUMA_KEEP_MEMINFO block to make it
> always available in the init section.
>
> Note that the issue was initially introduced with [1]. But since
> phys_to_target_node() was originally used that returned the valid node
> 0, an additional numa_memblk was not added. Though, the node id was
> wrong too.
>
> [1] commit fd49f99c1809 ("ACPI: NUMA: Add a node and memblk for each
> CFMWS not in SRAT")
>
> Fixes: 8f1004679987 ("ACPI/NUMA: Apply SRAT proximity domain to entire CFMWS window")
> Cc: Derick Marks <[email protected]>
> Cc: Dan Williams <[email protected]>
> Cc: Alison Schofield <[email protected]>
> Signed-off-by: Robert Richter <[email protected]>
> ---

with the assumption that this is passing 0-day builds...

Reviewed-by: Alison Schofield <[email protected]>


> arch/x86/include/asm/sparsemem.h | 2 +-
> arch/x86/mm/numa.c | 4 ++--
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/include/asm/sparsemem.h b/arch/x86/include/asm/sparsemem.h
> index 1be13b2dfe8b..1aaa447ef24b 100644
> --- a/arch/x86/include/asm/sparsemem.h
> +++ b/arch/x86/include/asm/sparsemem.h
> @@ -37,9 +37,9 @@ extern int phys_to_target_node(phys_addr_t start);
> #define phys_to_target_node phys_to_target_node
> extern int memory_add_physaddr_to_nid(u64 start);
> #define memory_add_physaddr_to_nid memory_add_physaddr_to_nid
> +#endif
> extern int numa_fill_memblks(u64 start, u64 end);
> #define numa_fill_memblks numa_fill_memblks
> -#endif
> #endif /* __ASSEMBLY__ */
>
> #endif /* _ASM_X86_SPARSEMEM_H */
> diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
> index 65e9a6e391c0..ce84ba86e69e 100644
> --- a/arch/x86/mm/numa.c
> +++ b/arch/x86/mm/numa.c
> @@ -929,6 +929,8 @@ int memory_add_physaddr_to_nid(u64 start)
> }
> EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
>
> +#endif
> +
> static int __init cmp_memblk(const void *a, const void *b)
> {
> const struct numa_memblk *ma = *(const struct numa_memblk **)a;
> @@ -1001,5 +1003,3 @@ int __init numa_fill_memblks(u64 start, u64 end)
> }
> return 0;
> }
> -
> -#endif
> --
> 2.39.2
>

2024-04-23 02:21:06

by Dan Williams

[permalink] [raw]
Subject: RE: [PATCH v3 1/5] x86/numa: Fix SRAT lookup of CFMWS ranges with numa_fill_memblks()

Robert Richter wrote:
> For configurations that have the kconfig option NUMA_KEEP_MEMINFO
> disabled, the SRAT lookup done with numa_fill_memblks() fails
> returning NUMA_NO_MEMBLK (-1). An existing SRAT memory range cannot be
> found for a CFMWS address range. This causes the addition of a
> duplicate numa_memblk with a different node id and a subsequent page
> fault and kernel crash during boot.
>
> numa_fill_memblks() is implemented and used in the init section only.
> The option NUMA_KEEP_MEMINFO is only for the case when NUMA data will
> be used outside of init. So fix the SRAT lookup by moving
> numa_fill_memblks() out of the NUMA_KEEP_MEMINFO block to make it
> always available in the init section.
>
> Note that the issue was initially introduced with [1]. But since
> phys_to_target_node() was originally used that returned the valid node
> 0, an additional numa_memblk was not added. Though, the node id was
> wrong too.

Wrong node seems worth notifying and we can figure out on the backend
where the backport makes sense.

>
> [1] commit fd49f99c1809 ("ACPI: NUMA: Add a node and memblk for each
> CFMWS not in SRAT")
>
> Fixes: 8f1004679987 ("ACPI/NUMA: Apply SRAT proximity domain to entire CFMWS window")
> Cc: Derick Marks <[email protected]>
> Cc: Dan Williams <[email protected]>
> Cc: Alison Schofield <[email protected]>
> Signed-off-by: Robert Richter <[email protected]>
> ---
> arch/x86/include/asm/sparsemem.h | 2 +-
> arch/x86/mm/numa.c | 4 ++--
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/include/asm/sparsemem.h b/arch/x86/include/asm/sparsemem.h
> index 1be13b2dfe8b..1aaa447ef24b 100644
> --- a/arch/x86/include/asm/sparsemem.h
> +++ b/arch/x86/include/asm/sparsemem.h
> @@ -37,9 +37,9 @@ extern int phys_to_target_node(phys_addr_t start);
> #define phys_to_target_node phys_to_target_node
> extern int memory_add_physaddr_to_nid(u64 start);
> #define memory_add_physaddr_to_nid memory_add_physaddr_to_nid
> +#endif
> extern int numa_fill_memblks(u64 start, u64 end);
> #define numa_fill_memblks numa_fill_memblks

It just feels like numa_fill_memblks() has absolutely no business being
defined in arch/x86/include/asm/sparsemem.h.

The only use for numa_fill_memblks() is to arrange for NUMA nodes to be
applied to memory ranges hot-onlined by the CXL driver.

It belongs right next to numa_add_memblk(), and I suspect
arch/x86/include/asm/sparsemem.h was only chosen to avoid figuring out
what to do about the fact that linux/numa.h does not include asm/numa.h
and that all implementations either provide numa_add_memblk() or select
the generic implementation.

So I would prefer that this do the proper fix and get
numa_fill_memblks() completely out of the sparsemem.h path.

Something like the following which boots for me:

diff --git a/arch/x86/include/asm/numa.h b/arch/x86/include/asm/numa.h
index ef2844d69173..12a93a3466c4 100644
--- a/arch/x86/include/asm/numa.h
+++ b/arch/x86/include/asm/numa.h
@@ -26,6 +26,7 @@ extern s16 __apicid_to_node[MAX_LOCAL_APIC];
extern nodemask_t numa_nodes_parsed __initdata;

extern int __init numa_add_memblk(int nodeid, u64 start, u64 end);
+extern int __init numa_fill_memblks(u64 start, u64 end);
extern void __init numa_set_distance(int from, int to, int distance);

static inline void set_apicid_to_node(int apicid, s16 node)
diff --git a/arch/x86/include/asm/sparsemem.h b/arch/x86/include/asm/sparsemem.h
index 1be13b2dfe8b..64df897c0ee3 100644
--- a/arch/x86/include/asm/sparsemem.h
+++ b/arch/x86/include/asm/sparsemem.h
@@ -37,8 +37,6 @@ extern int phys_to_target_node(phys_addr_t start);
#define phys_to_target_node phys_to_target_node
extern int memory_add_physaddr_to_nid(u64 start);
#define memory_add_physaddr_to_nid memory_add_physaddr_to_nid
-extern int numa_fill_memblks(u64 start, u64 end);
-#define numa_fill_memblks numa_fill_memblks
#endif
#endif /* __ASSEMBLY__ */

diff --git a/drivers/acpi/numa/srat.c b/drivers/acpi/numa/srat.c
index e45e64993c50..3b09fd39eeb4 100644
--- a/drivers/acpi/numa/srat.c
+++ b/drivers/acpi/numa/srat.c
@@ -208,6 +208,11 @@ int __init srat_disabled(void)
return acpi_numa < 0;
}

+__weak int __init numa_fill_memblks(u64 start, u64 end)
+{
+ return NUMA_NO_MEMBLK;
+}
+
#if defined(CONFIG_X86) || defined(CONFIG_ARM64) || defined(CONFIG_LOONGARCH)
/*
* Callback for SLIT parsing. pxm_to_node() returns NUMA_NO_NODE for
diff --git a/include/linux/numa.h b/include/linux/numa.h
index 915033a75731..8485d98e554d 100644
--- a/include/linux/numa.h
+++ b/include/linux/numa.h
@@ -36,13 +36,6 @@ int memory_add_physaddr_to_nid(u64 start);
int phys_to_target_node(u64 start);
#endif

-#ifndef numa_fill_memblks
-static inline int __init numa_fill_memblks(u64 start, u64 end)
-{
- return NUMA_NO_MEMBLK;
-}
-#endif
-
#else /* !CONFIG_NUMA */
static inline int numa_nearest_node(int node, unsigned int state)
{

2024-04-24 16:40:22

by Robert Richter

[permalink] [raw]
Subject: Re: [PATCH v3 1/5] x86/numa: Fix SRAT lookup of CFMWS ranges with numa_fill_memblks()

On 22.04.24 19:20:48, Dan Williams wrote:
> Robert Richter wrote:
> > For configurations that have the kconfig option NUMA_KEEP_MEMINFO
> > disabled, the SRAT lookup done with numa_fill_memblks() fails
> > returning NUMA_NO_MEMBLK (-1). An existing SRAT memory range cannot be
> > found for a CFMWS address range. This causes the addition of a
> > duplicate numa_memblk with a different node id and a subsequent page
> > fault and kernel crash during boot.
> >
> > numa_fill_memblks() is implemented and used in the init section only.
> > The option NUMA_KEEP_MEMINFO is only for the case when NUMA data will
> > be used outside of init. So fix the SRAT lookup by moving
> > numa_fill_memblks() out of the NUMA_KEEP_MEMINFO block to make it
> > always available in the init section.
> >
> > Note that the issue was initially introduced with [1]. But since
> > phys_to_target_node() was originally used that returned the valid node
> > 0, an additional numa_memblk was not added. Though, the node id was
> > wrong too.
>
> Wrong node seems worth notifying and we can figure out on the backend
> where the backport makes sense.

Updating the description here.

>
> >
> > [1] commit fd49f99c1809 ("ACPI: NUMA: Add a node and memblk for each
> > CFMWS not in SRAT")
> >
> > Fixes: 8f1004679987 ("ACPI/NUMA: Apply SRAT proximity domain to entire CFMWS window")
> > Cc: Derick Marks <[email protected]>
> > Cc: Dan Williams <[email protected]>
> > Cc: Alison Schofield <[email protected]>
> > Signed-off-by: Robert Richter <[email protected]>
> > ---
> > arch/x86/include/asm/sparsemem.h | 2 +-
> > arch/x86/mm/numa.c | 4 ++--
> > 2 files changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/x86/include/asm/sparsemem.h b/arch/x86/include/asm/sparsemem.h
> > index 1be13b2dfe8b..1aaa447ef24b 100644
> > --- a/arch/x86/include/asm/sparsemem.h
> > +++ b/arch/x86/include/asm/sparsemem.h
> > @@ -37,9 +37,9 @@ extern int phys_to_target_node(phys_addr_t start);
> > #define phys_to_target_node phys_to_target_node
> > extern int memory_add_physaddr_to_nid(u64 start);
> > #define memory_add_physaddr_to_nid memory_add_physaddr_to_nid
> > +#endif
> > extern int numa_fill_memblks(u64 start, u64 end);
> > #define numa_fill_memblks numa_fill_memblks
>
> It just feels like numa_fill_memblks() has absolutely no business being
> defined in arch/x86/include/asm/sparsemem.h.
>
> The only use for numa_fill_memblks() is to arrange for NUMA nodes to be
> applied to memory ranges hot-onlined by the CXL driver.
>
> It belongs right next to numa_add_memblk(), and I suspect
> arch/x86/include/asm/sparsemem.h was only chosen to avoid figuring out
> what to do about the fact that linux/numa.h does not include asm/numa.h
> and that all implementations either provide numa_add_memblk() or select
> the generic implementation.
>
> So I would prefer that this do the proper fix and get
> numa_fill_memblks() completely out of the sparsemem.h path.
>
> Something like the following which boots for me:

I have kept this patch as a stable change but took your patch on top.

Thanks,

-Robert