This patchset adds support for Vendor Defined Error types in the einj
module by exporting a binary blob file in module's debugfs directory.
Userspace tools can write OEM Defined Structures into the blob file as
part of injecting Vendor defined errors. Similarly, the very tools can
also read from the blob file for information, if any, provided by the
firmware after error injection.
The first patch refactors available_error_type_show() function to ensure
all errors supported by the platform are output through einj module's
available_error_type file in debugfs.
The second patch adds a write callback for binary blobs created through
debugfs_create_blob() API.
The third patch fixes the permissions of panicinfo file in debugfs to
ensure it remains read-only
The fourth patch adds the required support i.e. establishing the memory
mapping and exporting it through debugfs blob file for Vendor-defined
Error types.
Changes in v2:
- Split the v1 patch, as was recommended, to have a separate patch for
changes in debugfs.
- Refactored available_error_type_show() function into a separate patch.
- Changed file permissions to octal format to remove checkpatch warnings.
Changes in v3:
- Use BIT macro for generating error masks instead of hex values since
ACPI spec uses bit numbers.
- Handle the corner case of acpi_os_map_iomem() returning NULL through
a local variable to a store the size of OEM defined data structure.
Changes in v4:
- Fix permissions for panicinfo file in debugfs.
- Replace acpi_os_map_iomem() and acpi_os_unmap_iomem() calls with
acpi_os_map_memory() and acpi_os_unmap_memory() respectively to avert
sparse warnings as suggested by Alexey.
Changes in v5:
- Change permissions of the "oem_error" file, being created in einj
module's debugfs directory, from "w" to "rw" since system firmware
in some cases might provide some information through OEM-defined
structure for tools to consume.
- Remove Reviewed-by: Alexey Kardashevskiy <[email protected]> from the
fourth patch since permissions of the oem_error file have changed.
- Add Reviewed-by: Greg Kroah-Hartman <[email protected]> for
second and third patch.
- Rebase on top of tip master.
Changes in v6:
- Minor formatting undertaken in the first and fourth patch per v5
feedback by Boris.
- Added check in the second patch to ensure that only owners can write
into the binary blob files. Mentioned the same in commit description.
- Modified commit description of the third patch per recommendations
provided by Tony.
- Add Reviewed-by: Borislav Petkov (AMD) <[email protected]> for first and
fourth patch.
- Add Reviewed-by: Tony Luck <[email protected]> for second, third and
fourth patch.
[NOTE:
- The second patch already had the below tags for v5:
Reviewed-by: Alexey Kardashevskiy <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Since the changes to the patch for v6 are very minimal i.e. addition of
a check to ensure that only owners write into the blobs, have retained
the tags for v6 as well.
- Similarly, the third patch already had the below tag for v5:
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Since only the commit description was slightly changed for this patch
in v6, have retained the tag for v6 too.
Having said so, if advised, will attempt to reacquire the tags.]
Avadhut Naik (4):
ACPI: APEI: EINJ: Refactor available_error_type_show()
fs: debugfs: Add write functionality to debugfs blobs
platform/chrome: cros_ec_debugfs: Fix permissions for panicinfo
ACPI: APEI: EINJ: Add support for vendor defined error types
drivers/acpi/apei/einj.c | 71 +++++++++++++++--------
drivers/platform/chrome/cros_ec_debugfs.c | 2 +-
fs/debugfs/file.c | 28 +++++++--
3 files changed, 72 insertions(+), 29 deletions(-)
base-commit: a1cc6ec03d1e56b795607fce8442222b37d1dd99
--
2.34.1
From: Avadhut Naik <[email protected]>
OSPM can discover the error injection capabilities of the platform by
executing GET_ERROR_TYPE error injection action.[1] The action returns
a DWORD representing a bitmap of platform supported error injections.[2]
The available_error_type_show() function determines the bits set within
this DWORD and provides a verbose output, from einj_error_type_string
array, through /sys/kernel/debug/apei/einj/available_error_type file.
The function however, assumes one to one correspondence between an error's
position in the bitmap and its array entry offset. Consequently, some
errors like Vendor Defined Error Type fail this assumption and will
incorrectly be shown as not supported, even if their corresponding bit is
set in the bitmap and they have an entry in the array.
Navigate around the issue by converting einj_error_type_string into an
array of structures with a predetermined mask for all error types
corresponding to their bit position in the DWORD returned by GET_ERROR_TYPE
action. The same breaks the aforementioned assumption resulting in all
supported error types by a platform being outputted through the above
available_error_type file.
[1] ACPI specification 6.5, Table 18.25
[2] ACPI specification 6.5, Table 18.30
Suggested-by: Alexey Kardashevskiy <[email protected]>
Signed-off-by: Avadhut Naik <[email protected]>
Reviewed-by: Borislav Petkov (AMD) <[email protected]>
---
drivers/acpi/apei/einj.c | 47 ++++++++++++++++++++--------------------
1 file changed, 24 insertions(+), 23 deletions(-)
diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj.c
index 013eb621dc92..506fe319379f 100644
--- a/drivers/acpi/apei/einj.c
+++ b/drivers/acpi/apei/einj.c
@@ -577,38 +577,39 @@ static u64 error_param2;
static u64 error_param3;
static u64 error_param4;
static struct dentry *einj_debug_dir;
-static const char * const einj_error_type_string[] = {
- "0x00000001\tProcessor Correctable\n",
- "0x00000002\tProcessor Uncorrectable non-fatal\n",
- "0x00000004\tProcessor Uncorrectable fatal\n",
- "0x00000008\tMemory Correctable\n",
- "0x00000010\tMemory Uncorrectable non-fatal\n",
- "0x00000020\tMemory Uncorrectable fatal\n",
- "0x00000040\tPCI Express Correctable\n",
- "0x00000080\tPCI Express Uncorrectable non-fatal\n",
- "0x00000100\tPCI Express Uncorrectable fatal\n",
- "0x00000200\tPlatform Correctable\n",
- "0x00000400\tPlatform Uncorrectable non-fatal\n",
- "0x00000800\tPlatform Uncorrectable fatal\n",
- "0x00001000\tCXL.cache Protocol Correctable\n",
- "0x00002000\tCXL.cache Protocol Uncorrectable non-fatal\n",
- "0x00004000\tCXL.cache Protocol Uncorrectable fatal\n",
- "0x00008000\tCXL.mem Protocol Correctable\n",
- "0x00010000\tCXL.mem Protocol Uncorrectable non-fatal\n",
- "0x00020000\tCXL.mem Protocol Uncorrectable fatal\n",
+static struct { u32 mask; const char *str; } const einj_error_type_string[] = {
+ { BIT(0), "Processor Correctable" },
+ { BIT(1), "Processor Uncorrectable non-fatal" },
+ { BIT(2), "Processor Uncorrectable fatal" },
+ { BIT(3), "Memory Correctable" },
+ { BIT(4), "Memory Uncorrectable non-fatal" },
+ { BIT(5), "Memory Uncorrectable fatal" },
+ { BIT(6), "PCI Express Correctable" },
+ { BIT(7), "PCI Express Uncorrectable non-fatal" },
+ { BIT(8), "PCI Express Uncorrectable fatal" },
+ { BIT(9), "Platform Correctable" },
+ { BIT(10), "Platform Uncorrectable non-fatal" },
+ { BIT(11), "Platform Uncorrectable fatal"},
+ { BIT(12), "CXL.cache Protocol Correctable" },
+ { BIT(13), "CXL.cache Protocol Uncorrectable non-fatal" },
+ { BIT(14), "CXL.cache Protocol Uncorrectable fatal" },
+ { BIT(15), "CXL.mem Protocol Correctable" },
+ { BIT(16), "CXL.mem Protocol Uncorrectable non-fatal" },
+ { BIT(17), "CXL.mem Protocol Uncorrectable fatal" },
};
static int available_error_type_show(struct seq_file *m, void *v)
{
int rc;
- u32 available_error_type = 0;
+ u32 error_type = 0;
- rc = einj_get_available_error_type(&available_error_type);
+ rc = einj_get_available_error_type(&error_type);
if (rc)
return rc;
for (int pos = 0; pos < ARRAY_SIZE(einj_error_type_string); pos++)
- if (available_error_type & BIT(pos))
- seq_puts(m, einj_error_type_string[pos]);
+ if (error_type & einj_error_type_string[pos].mask)
+ seq_printf(m, "0x%08x\t%s\n", einj_error_type_string[pos].mask,
+ einj_error_type_string[pos].str);
return 0;
}
--
2.34.1
From: Avadhut Naik <[email protected]>
The debugfs_create_blob() function has been used to create read-only binary
blobs in debugfs. The function filters out permissions, other than S_IRUSR,
S_IRGRP and S_IROTH, provided while creating the blobs.
The very behavior though is being changed through previous patch in the
series (fs: debugfs: Add write functionality to debugfs blobs) which makes
the binary blobs writable by owners. Thus, all permissions provided while
creating the blobs, except S_IRUSR,S_IWUSR, S_IRGRP, S_IROTH, will be
filtered by debugfs_create_blob().
As such, rectify the permissions of panicinfo file since the S_IFREG flag
was anyways being filtered out by debugfs_create_blob(). Moreover, the
very flag will always be set be set for the panicinfo file through
__debugfs_create_file().
Signed-off-by: Avadhut Naik <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Reviewed-by: Tony Luck <[email protected]>
---
drivers/platform/chrome/cros_ec_debugfs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/platform/chrome/cros_ec_debugfs.c b/drivers/platform/chrome/cros_ec_debugfs.c
index 091fdc154d79..6bf6f0e7b597 100644
--- a/drivers/platform/chrome/cros_ec_debugfs.c
+++ b/drivers/platform/chrome/cros_ec_debugfs.c
@@ -454,7 +454,7 @@ static int cros_ec_create_panicinfo(struct cros_ec_debugfs *debug_info)
debug_info->panicinfo_blob.data = data;
debug_info->panicinfo_blob.size = ret;
- debugfs_create_blob("panicinfo", S_IFREG | 0444, debug_info->dir,
+ debugfs_create_blob("panicinfo", 0444, debug_info->dir,
&debug_info->panicinfo_blob);
return 0;
--
2.34.1
From: Avadhut Naik <[email protected]>
Currently, debugfs_create_blob() creates read-only debugfs binary blob
files.
In some cases, however, userspace tools need to write variable length
data structures into predetermined memory addresses. An example is when
injecting Vendor-defined error types through the einj module. In such
cases, the functionality to write to these blob files in debugfs would
be desired since the mapping aspect can be handled within the modules
with userspace tools only needing to write into the blob files.
Implement a write callback to enable writing to these blob files, created
in debugfs, by owners only.
Signed-off-by: Avadhut Naik <[email protected]>
Reviewed-by: Alexey Kardashevskiy <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Reviewed-by: Tony Luck <[email protected]>
---
fs/debugfs/file.c | 28 +++++++++++++++++++++++-----
1 file changed, 23 insertions(+), 5 deletions(-)
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index c45e8c2d62e1..00b834269aad 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -1008,17 +1008,35 @@ static ssize_t read_file_blob(struct file *file, char __user *user_buf,
return r;
}
+static ssize_t write_file_blob(struct file *file, const char __user *user_buf,
+ size_t count, loff_t *ppos)
+{
+ struct debugfs_blob_wrapper *blob = file->private_data;
+ struct dentry *dentry = F_DENTRY(file);
+ ssize_t r;
+
+ r = debugfs_file_get(dentry);
+ if (unlikely(r))
+ return r;
+ r = simple_write_to_buffer(blob->data, blob->size, ppos, user_buf,
+ count);
+
+ debugfs_file_put(dentry);
+ return r;
+}
+
static const struct file_operations fops_blob = {
.read = read_file_blob,
+ .write = write_file_blob,
.open = simple_open,
.llseek = default_llseek,
};
/**
- * debugfs_create_blob - create a debugfs file that is used to read a binary blob
+ * debugfs_create_blob - create a debugfs file that is used to read and write
+ * a binary blob
* @name: a pointer to a string containing the name of the file to create.
- * @mode: the read permission that the file should have (other permissions are
- * masked out)
+ * @mode: the permission that the file should have
* @parent: a pointer to the parent dentry for this file. This should be a
* directory dentry if set. If this parameter is %NULL, then the
* file will be created in the root of the debugfs filesystem.
@@ -1027,7 +1045,7 @@ static const struct file_operations fops_blob = {
*
* This function creates a file in debugfs with the given name that exports
* @blob->data as a binary blob. If the @mode variable is so set it can be
- * read from. Writing is not supported.
+ * read from and written to.
*
* This function will return a pointer to a dentry if it succeeds. This
* pointer must be passed to the debugfs_remove() function when the file is
@@ -1042,7 +1060,7 @@ struct dentry *debugfs_create_blob(const char *name, umode_t mode,
struct dentry *parent,
struct debugfs_blob_wrapper *blob)
{
- return debugfs_create_file_unsafe(name, mode & 0444, parent, blob, &fops_blob);
+ return debugfs_create_file_unsafe(name, mode & 0644, parent, blob, &fops_blob);
}
EXPORT_SYMBOL_GPL(debugfs_create_blob);
--
2.34.1
From: Avadhut Naik <[email protected]>
Vendor-Defined Error types are supported by the platform apart from
standard error types if bit 31 is set in the output of GET_ERROR_TYPE
Error Injection Action.[1] While the errors themselves and the length
of their associated "OEM Defined data structure" might vary between
vendors, the physical address of this structure can be computed through
vendor_extension and length fields of "SET_ERROR_TYPE_WITH_ADDRESS" and
"Vendor Error Type Extension" Structures respectively.[2][3]
Currently, however, the einj module only computes the physical address of
Vendor Error Type Extension Structure. Neither does it compute the physical
address of OEM Defined structure nor does it establish the memory mapping
required for injecting Vendor-defined errors. Consequently, userspace
tools have to establish the very mapping through /dev/mem, nopat kernel
parameter and system calls like mmap/munmap initially before injecting
Vendor-defined errors.
Circumvent the issue by computing the physical address of OEM Defined data
structure and establishing the required mapping with the structure. Create
a new file "oem_error", if the system supports Vendor-defined errors, to
export this mapping, through debugfs_create_blob(). Userspace tools can
then populate their respective OEM Defined structure instances and just
write to the file as part of injecting Vendor-defined Errors. Similarly,
the tools can also read from the file if the system firmware provides some
information through the OEM defined structure after error injection.
[1] ACPI specification 6.5, section 18.6.4
[2] ACPI specification 6.5, Table 18.31
[3] ACPI specification 6.5, Table 18.32
Suggested-by: Yazen Ghannam <[email protected]>
Signed-off-by: Avadhut Naik <[email protected]>
Reviewed-by: Tony Luck <[email protected]>
Reviewed-by: Borislav Petkov (AMD) <[email protected]>
---
drivers/acpi/apei/einj.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/drivers/acpi/apei/einj.c b/drivers/acpi/apei/einj.c
index 506fe319379f..89fb9331c611 100644
--- a/drivers/acpi/apei/einj.c
+++ b/drivers/acpi/apei/einj.c
@@ -73,6 +73,7 @@ static u32 notrigger;
static u32 vendor_flags;
static struct debugfs_blob_wrapper vendor_blob;
+static struct debugfs_blob_wrapper vendor_errors;
static char vendor_dev[64];
/*
@@ -182,6 +183,21 @@ static int einj_timedout(u64 *t)
return 0;
}
+static void get_oem_vendor_struct(u64 paddr, int offset,
+ struct vendor_error_type_extension *v)
+{
+ unsigned long vendor_size;
+ u64 target_pa = paddr + offset + sizeof(struct vendor_error_type_extension);
+
+ vendor_size = v->length - sizeof(struct vendor_error_type_extension);
+
+ if (vendor_size)
+ vendor_errors.data = acpi_os_map_memory(target_pa, vendor_size);
+
+ if (vendor_errors.data)
+ vendor_errors.size = vendor_size;
+}
+
static void check_vendor_extension(u64 paddr,
struct set_error_type_with_address *v5param)
{
@@ -194,6 +210,7 @@ static void check_vendor_extension(u64 paddr,
v = acpi_os_map_iomem(paddr + offset, sizeof(*v));
if (!v)
return;
+ get_oem_vendor_struct(paddr, offset, v);
sbdf = v->pcie_sbdf;
sprintf(vendor_dev, "%x:%x:%x.%x vendor_id=%x device_id=%x rev_id=%x\n",
sbdf >> 24, (sbdf >> 16) & 0xff,
@@ -596,6 +613,7 @@ static struct { u32 mask; const char *str; } const einj_error_type_string[] = {
{ BIT(15), "CXL.mem Protocol Correctable" },
{ BIT(16), "CXL.mem Protocol Uncorrectable non-fatal" },
{ BIT(17), "CXL.mem Protocol Uncorrectable fatal" },
+ { BIT(31), "Vendor Defined Error Types" },
};
static int available_error_type_show(struct seq_file *m, void *v)
@@ -768,6 +786,10 @@ static int __init einj_init(void)
einj_debug_dir, &vendor_flags);
}
+ if (vendor_errors.size)
+ debugfs_create_blob("oem_error", 0600, einj_debug_dir,
+ &vendor_errors);
+
pr_info("Error INJection is initialized.\n");
return 0;
@@ -793,6 +815,8 @@ static void __exit einj_exit(void)
sizeof(struct einj_parameter);
acpi_os_unmap_iomem(einj_param, size);
+ if (vendor_errors.size)
+ acpi_os_unmap_memory(vendor_errors.data, vendor_errors.size);
}
einj_exec_ctx_init(&ctx);
apei_exec_post_unmap_gars(&ctx);
--
2.34.1
> From: Avadhut Naik <[email protected]>
>
> OSPM can discover the error injection capabilities of the platform by
> executing GET_ERROR_TYPE error injection action.[1] The action returns
> a DWORD representing a bitmap of platform supported error injections.[2]
>
> The available_error_type_show() function determines the bits set within
> this DWORD and provides a verbose output, from einj_error_type_string
> array, through /sys/kernel/debug/apei/einj/available_error_type file.
>
> The function however, assumes one to one correspondence between an error's
> position in the bitmap and its array entry offset. Consequently, some
> errors like Vendor Defined Error Type fail this assumption and will
> incorrectly be shown as not supported, even if their corresponding bit is
> set in the bitmap and they have an entry in the array.
>
> Navigate around the issue by converting einj_error_type_string into an
> array of structures with a predetermined mask for all error types
> corresponding to their bit position in the DWORD returned by GET_ERROR_TYPE
> action. The same breaks the aforementioned assumption resulting in all
> supported error types by a platform being outputted through the above
> available_error_type file.
>
> [1] ACPI specification 6.5, Table 18.25
> [2] ACPI specification 6.5, Table 18.30
>
> Suggested-by: Alexey Kardashevskiy <[email protected]>
> Signed-off-by: Avadhut Naik <[email protected]>
> Reviewed-by: Borislav Petkov (AMD) <[email protected]>
Reviewed-by: Tony Luck <[email protected]>
On Thu, Nov 16, 2023 at 11:47 PM Avadhut Naik <[email protected]> wrote:
>
> This patchset adds support for Vendor Defined Error types in the einj
> module by exporting a binary blob file in module's debugfs directory.
> Userspace tools can write OEM Defined Structures into the blob file as
> part of injecting Vendor defined errors. Similarly, the very tools can
> also read from the blob file for information, if any, provided by the
> firmware after error injection.
>
> The first patch refactors available_error_type_show() function to ensure
> all errors supported by the platform are output through einj module's
> available_error_type file in debugfs.
>
> The second patch adds a write callback for binary blobs created through
> debugfs_create_blob() API.
>
> The third patch fixes the permissions of panicinfo file in debugfs to
> ensure it remains read-only
>
> The fourth patch adds the required support i.e. establishing the memory
> mapping and exporting it through debugfs blob file for Vendor-defined
> Error types.
>
> Changes in v2:
> - Split the v1 patch, as was recommended, to have a separate patch for
> changes in debugfs.
> - Refactored available_error_type_show() function into a separate patch.
> - Changed file permissions to octal format to remove checkpatch warnings.
>
> Changes in v3:
> - Use BIT macro for generating error masks instead of hex values since
> ACPI spec uses bit numbers.
> - Handle the corner case of acpi_os_map_iomem() returning NULL through
> a local variable to a store the size of OEM defined data structure.
>
> Changes in v4:
> - Fix permissions for panicinfo file in debugfs.
> - Replace acpi_os_map_iomem() and acpi_os_unmap_iomem() calls with
> acpi_os_map_memory() and acpi_os_unmap_memory() respectively to avert
> sparse warnings as suggested by Alexey.
>
> Changes in v5:
> - Change permissions of the "oem_error" file, being created in einj
> module's debugfs directory, from "w" to "rw" since system firmware
> in some cases might provide some information through OEM-defined
> structure for tools to consume.
> - Remove Reviewed-by: Alexey Kardashevskiy <[email protected]> from the
> fourth patch since permissions of the oem_error file have changed.
> - Add Reviewed-by: Greg Kroah-Hartman <[email protected]> for
> second and third patch.
> - Rebase on top of tip master.
>
> Changes in v6:
> - Minor formatting undertaken in the first and fourth patch per v5
> feedback by Boris.
> - Added check in the second patch to ensure that only owners can write
> into the binary blob files. Mentioned the same in commit description.
> - Modified commit description of the third patch per recommendations
> provided by Tony.
> - Add Reviewed-by: Borislav Petkov (AMD) <[email protected]> for first and
> fourth patch.
> - Add Reviewed-by: Tony Luck <[email protected]> for second, third and
> fourth patch.
>
>
> [NOTE:
>
> - The second patch already had the below tags for v5:
> Reviewed-by: Alexey Kardashevskiy <[email protected]>
> Reviewed-by: Greg Kroah-Hartman <[email protected]>
>
> Since the changes to the patch for v6 are very minimal i.e. addition of
> a check to ensure that only owners write into the blobs, have retained
> the tags for v6 as well.
>
> - Similarly, the third patch already had the below tag for v5:
> Reviewed-by: Greg Kroah-Hartman <[email protected]>
>
> Since only the commit description was slightly changed for this patch
> in v6, have retained the tag for v6 too.
>
> Having said so, if advised, will attempt to reacquire the tags.]
>
>
> Avadhut Naik (4):
> ACPI: APEI: EINJ: Refactor available_error_type_show()
> fs: debugfs: Add write functionality to debugfs blobs
> platform/chrome: cros_ec_debugfs: Fix permissions for panicinfo
> ACPI: APEI: EINJ: Add support for vendor defined error types
>
> drivers/acpi/apei/einj.c | 71 +++++++++++++++--------
> drivers/platform/chrome/cros_ec_debugfs.c | 2 +-
> fs/debugfs/file.c | 28 +++++++--
> 3 files changed, 72 insertions(+), 29 deletions(-)
>
>
> base-commit: a1cc6ec03d1e56b795607fce8442222b37d1dd99
> --
All patches in the series applied as 6.8 material, thanks!