With compression initialization now separated from pstore_register(),
there is no longer a good reason to do compression method selection
during fs init. Instead, merge everything together into the late init.
Additionally cleans up the reporting to be more clear.
Signed-off-by: Kees Cook <[email protected]>
---
This patch goes on top of Joel's. I'll have both in linux-next shortly...
---
fs/pstore/inode.c | 2 --
fs/pstore/internal.h | 3 --
fs/pstore/platform.c | 65 ++++++++++++++++++++++++++++----------------
3 files changed, 41 insertions(+), 29 deletions(-)
diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
index 5fcb845b9fec..d814723fb27d 100644
--- a/fs/pstore/inode.c
+++ b/fs/pstore/inode.c
@@ -486,8 +486,6 @@ static int __init init_pstore_fs(void)
{
int err;
- pstore_choose_compression();
-
/* Create a convenient mount point for people to access pstore */
err = sysfs_create_mount_point(fs_kobj, "pstore");
if (err)
diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h
index fb767e28aeb2..c029314478fa 100644
--- a/fs/pstore/internal.h
+++ b/fs/pstore/internal.h
@@ -37,7 +37,4 @@ extern bool pstore_is_mounted(void);
extern void pstore_record_init(struct pstore_record *record,
struct pstore_info *psi);
-/* Called during module_init() */
-extern void __init pstore_choose_compression(void);
-
#endif
diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index f09066db2d4d..e4737a5fa68c 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -274,36 +274,56 @@ static int pstore_decompress(void *in, void *out,
static void allocate_buf_for_compression(void)
{
+ struct crypto_comp *ctx;
+ int size;
+ char *buf;
+
+ /* Skip if not built-in or compression backend not selected yet. */
if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !zbackend)
return;
+ /* Skip if no pstore backend yet or compression init already done. */
+ if (!psinfo || tfm)
+ return;
+
if (!crypto_has_comp(zbackend->name, 0, 0)) {
- pr_err("No %s compression\n", zbackend->name);
+ pr_err("Unknown compression: %s\n", zbackend->name);
return;
}
- big_oops_buf_sz = zbackend->zbufsize(psinfo->bufsize);
- if (big_oops_buf_sz <= 0)
+ size = zbackend->zbufsize(psinfo->bufsize);
+ if (size <= 0) {
+ pr_err("Invalid compression size for %s: %d\n",
+ zbackend->name, size);
return;
+ }
- big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
- if (!big_oops_buf) {
- pr_err("allocate compression buffer error!\n");
+ buf = kmalloc(size, GFP_KERNEL);
+ if (!buf) {
+ pr_err("Failed %d byte compression buffer allocation for: %s\n",
+ size, zbackend->name);
return;
}
- tfm = crypto_alloc_comp(zbackend->name, 0, 0);
- if (IS_ERR_OR_NULL(tfm)) {
- kfree(big_oops_buf);
- big_oops_buf = NULL;
- pr_err("crypto_alloc_comp() failed!\n");
+ ctx = crypto_alloc_comp(zbackend->name, 0, 0);
+ if (IS_ERR_OR_NULL(ctx)) {
+ kfree(buf);
+ pr_err("crypto_alloc_comp('%s') failed: %ld\n", zbackend->name,
+ PTR_ERR(ctx));
return;
}
+
+ /* A non-NULL big_oops_buf indicates compression is available. */
+ tfm = ctx;
+ big_oops_buf_sz = size;
+ big_oops_buf = buf;
+
+ pr_info("Using compression: %s\n", zbackend->name);
}
static void free_buf_for_compression(void)
{
- if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && !IS_ERR_OR_NULL(tfm))
+ if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && tfm)
crypto_free_comp(tfm);
kfree(big_oops_buf);
big_oops_buf = NULL;
@@ -764,31 +784,28 @@ static void pstore_timefunc(struct timer_list *unused)
jiffies + msecs_to_jiffies(pstore_update_ms));
}
-void __init pstore_choose_compression(void)
+static int __init pstore_compression_late_init(void)
{
const struct pstore_zbackend *step;
if (!compress)
- return;
+ return 0;
+ /* Locate desired compression method. */
for (step = zbackends; step->name; step++) {
if (!strcmp(compress, step->name)) {
zbackend = step;
- pr_info("using %s compression\n", zbackend->name);
- return;
+ break;
}
}
-}
-static int __init pstore_compression_late_init(void)
-{
/*
- * Check if any pstore backends registered earlier but did not allocate
- * for compression because crypto was not ready, if so then initialize
- * compression.
+ * Check if any pstore backends registered earlier but did not
+ * initialize compression because crypto was not ready. If so,
+ * then initialize compression now.
*/
- if (psinfo && !tfm)
- allocate_buf_for_compression();
+ allocate_buf_for_compression();
+
return 0;
}
late_initcall(pstore_compression_late_init);
--
2.17.1
--
Kees Cook
Pixel Security
On Wed, Oct 17, 2018 at 02:41:24PM -0700, Kees Cook wrote:
> With compression initialization now separated from pstore_register(),
> there is no longer a good reason to do compression method selection
> during fs init. Instead, merge everything together into the late init.
> Additionally cleans up the reporting to be more clear.
>
> Signed-off-by: Kees Cook <[email protected]>
> ---
> This patch goes on top of Joel's. I'll have both in linux-next shortly...
> ---
> fs/pstore/inode.c | 2 --
> fs/pstore/internal.h | 3 --
> fs/pstore/platform.c | 65 ++++++++++++++++++++++++++++----------------
> 3 files changed, 41 insertions(+), 29 deletions(-)
>
> diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
> index 5fcb845b9fec..d814723fb27d 100644
> --- a/fs/pstore/inode.c
> +++ b/fs/pstore/inode.c
> @@ -486,8 +486,6 @@ static int __init init_pstore_fs(void)
> {
> int err;
>
> - pstore_choose_compression();
> -
> /* Create a convenient mount point for people to access pstore */
> err = sysfs_create_mount_point(fs_kobj, "pstore");
> if (err)
> diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h
> index fb767e28aeb2..c029314478fa 100644
> --- a/fs/pstore/internal.h
> +++ b/fs/pstore/internal.h
> @@ -37,7 +37,4 @@ extern bool pstore_is_mounted(void);
> extern void pstore_record_init(struct pstore_record *record,
> struct pstore_info *psi);
>
> -/* Called during module_init() */
> -extern void __init pstore_choose_compression(void);
> -
> #endif
> diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
> index f09066db2d4d..e4737a5fa68c 100644
> --- a/fs/pstore/platform.c
> +++ b/fs/pstore/platform.c
> @@ -274,36 +274,56 @@ static int pstore_decompress(void *in, void *out,
>
> static void allocate_buf_for_compression(void)
> {
> + struct crypto_comp *ctx;
> + int size;
> + char *buf;
> +
> + /* Skip if not built-in or compression backend not selected yet. */
> if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !zbackend)
> return;
>
> + /* Skip if no pstore backend yet or compression init already done. */
> + if (!psinfo || tfm)
> + return;
> +
> if (!crypto_has_comp(zbackend->name, 0, 0)) {
> - pr_err("No %s compression\n", zbackend->name);
> + pr_err("Unknown compression: %s\n", zbackend->name);
> return;
> }
>
> - big_oops_buf_sz = zbackend->zbufsize(psinfo->bufsize);
> - if (big_oops_buf_sz <= 0)
> + size = zbackend->zbufsize(psinfo->bufsize);
> + if (size <= 0) {
> + pr_err("Invalid compression size for %s: %d\n",
> + zbackend->name, size);
> return;
> + }
>
> - big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
> - if (!big_oops_buf) {
> - pr_err("allocate compression buffer error!\n");
> + buf = kmalloc(size, GFP_KERNEL);
> + if (!buf) {
> + pr_err("Failed %d byte compression buffer allocation for: %s\n",
> + size, zbackend->name);
> return;
> }
>
> - tfm = crypto_alloc_comp(zbackend->name, 0, 0);
> - if (IS_ERR_OR_NULL(tfm)) {
> - kfree(big_oops_buf);
> - big_oops_buf = NULL;
> - pr_err("crypto_alloc_comp() failed!\n");
> + ctx = crypto_alloc_comp(zbackend->name, 0, 0);
> + if (IS_ERR_OR_NULL(ctx)) {
> + kfree(buf);
> + pr_err("crypto_alloc_comp('%s') failed: %ld\n", zbackend->name,
> + PTR_ERR(ctx));
> return;
> }
> +
> + /* A non-NULL big_oops_buf indicates compression is available. */
> + tfm = ctx;
> + big_oops_buf_sz = size;
> + big_oops_buf = buf;
> +
> + pr_info("Using compression: %s\n", zbackend->name);
> }
>
> static void free_buf_for_compression(void)
> {
> - if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && !IS_ERR_OR_NULL(tfm))
> + if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && tfm)
> crypto_free_comp(tfm);
> kfree(big_oops_buf);
> big_oops_buf = NULL;
> @@ -764,31 +784,28 @@ static void pstore_timefunc(struct timer_list *unused)
> jiffies + msecs_to_jiffies(pstore_update_ms));
> }
>
> -void __init pstore_choose_compression(void)
> +static int __init pstore_compression_late_init(void)
> {
> const struct pstore_zbackend *step;
>
> if (!compress)
> - return;
> + return 0;
>
> + /* Locate desired compression method. */
> for (step = zbackends; step->name; step++) {
> if (!strcmp(compress, step->name)) {
> zbackend = step;
> - pr_info("using %s compression\n", zbackend->name);
> - return;
> + break;
> }
> }
> -}
>
> -static int __init pstore_compression_late_init(void)
> -{
> /*
> - * Check if any pstore backends registered earlier but did not allocate
> - * for compression because crypto was not ready, if so then initialize
> - * compression.
> + * Check if any pstore backends registered earlier but did not
> + * initialize compression because crypto was not ready. If so,
> + * then initialize compression now.
> */
> - if (psinfo && !tfm)
> - allocate_buf_for_compression();
> + allocate_buf_for_compression();
We can also get rid of the 'zbackend' global variable since choosing the
compression backend and allocating the buffers are done at the same time?
Otherwise looks good to me,
Reviewed-by: Joel Fernandes (Google) <[email protected]>
thanks,
- Joel
On 10/18/2018 7:00 AM, Joel Fernandes wrote:
On Wed, Oct 17, 2018 at 02:41:24PM -0700, Kees Cook wrote:
>> With compression initialization now separated from pstore_register(),
>> there is no longer a good reason to do compression method selection
>> during fs init. Instead, merge everything together into the late init.
>> Additionally cleans up the reporting to be more clear.
>>
>> Signed-off-by: Kees Cook <[email protected]>
>> ---
>> This patch goes on top of Joel's. I'll have both in linux-next shortly...
>> ---
>> fs/pstore/inode.c | 2 --
>> fs/pstore/internal.h | 3 --
>> fs/pstore/platform.c | 65 ++++++++++++++++++++++++++++----------------
>> 3 files changed, 41 insertions(+), 29 deletions(-)
>>
>> diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
>> index 5fcb845b9fec..d814723fb27d 100644
>> --- a/fs/pstore/inode.c
>> +++ b/fs/pstore/inode.c
>> @@ -486,8 +486,6 @@ static int __init init_pstore_fs(void)
>> {
>> int err;
>>
>> - pstore_choose_compression();
>> -
>> /* Create a convenient mount point for people to access pstore */
>> err = sysfs_create_mount_point(fs_kobj, "pstore");
>> if (err)
>> diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h
>> index fb767e28aeb2..c029314478fa 100644
>> --- a/fs/pstore/internal.h
>> +++ b/fs/pstore/internal.h
>> @@ -37,7 +37,4 @@ extern bool pstore_is_mounted(void);
>> extern void pstore_record_init(struct pstore_record *record,
>> struct pstore_info *psi);
>>
>> -/* Called during module_init() */
>> -extern void __init pstore_choose_compression(void);
>> -
>> #endif
>> diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
>> index f09066db2d4d..e4737a5fa68c 100644
>> --- a/fs/pstore/platform.c
>> +++ b/fs/pstore/platform.c
>> @@ -274,36 +274,56 @@ static int pstore_decompress(void *in, void *out,
>>
>> static void allocate_buf_for_compression(void)
>> {
>> + struct crypto_comp *ctx;
>> + int size;
>> + char *buf;
>> +
>> + /* Skip if not built-in or compression backend not selected yet. */
>> if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !zbackend)
>> return;
>>
>> + /* Skip if no pstore backend yet or compression init already done. */
>> + if (!psinfo || tfm)
>> + return;
>> +
>> if (!crypto_has_comp(zbackend->name, 0, 0)) {
>> - pr_err("No %s compression\n", zbackend->name);
>> + pr_err("Unknown compression: %s\n", zbackend->name);
>> return;
>> }
>>
>> - big_oops_buf_sz = zbackend->zbufsize(psinfo->bufsize);
>> - if (big_oops_buf_sz <= 0)
>> + size = zbackend->zbufsize(psinfo->bufsize);
>> + if (size <= 0) {
>> + pr_err("Invalid compression size for %s: %d\n",
>> + zbackend->name, size);
>> return;
>> + }
>>
>> - big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
>> - if (!big_oops_buf) {
>> - pr_err("allocate compression buffer error!\n");
>> + buf = kmalloc(size, GFP_KERNEL);
>> + if (!buf) {
>> + pr_err("Failed %d byte compression buffer allocation for: %s\n",
>> + size, zbackend->name);
>> return;
>> }
>>
>> - tfm = crypto_alloc_comp(zbackend->name, 0, 0);
>> - if (IS_ERR_OR_NULL(tfm)) {
>> - kfree(big_oops_buf);
>> - big_oops_buf = NULL;
>> - pr_err("crypto_alloc_comp() failed!\n");
>> + ctx = crypto_alloc_comp(zbackend->name, 0, 0);
>> + if (IS_ERR_OR_NULL(ctx)) {
>> + kfree(buf);
>> + pr_err("crypto_alloc_comp('%s') failed: %ld\n", zbackend->name,
>> + PTR_ERR(ctx));
>> return;
>> }
>> +
>> + /* A non-NULL big_oops_buf indicates compression is available. */
>> + tfm = ctx;
>> + big_oops_buf_sz = size;
>> + big_oops_buf = buf;
>> +
>> + pr_info("Using compression: %s\n", zbackend->name);
>> }
>>
>> static void free_buf_for_compression(void)
>> {
>> - if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && !IS_ERR_OR_NULL(tfm))
>> + if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && tfm)
>> crypto_free_comp(tfm);
>> kfree(big_oops_buf);
>> big_oops_buf = NULL;
>> @@ -764,31 +784,28 @@ static void pstore_timefunc(struct timer_list *unused)
>> jiffies + msecs_to_jiffies(pstore_update_ms));
>> }
>>
>> -void __init pstore_choose_compression(void)
>> +static int __init pstore_compression_late_init(void)
>> {
>> const struct pstore_zbackend *step;
>>
>> if (!compress)
>> - return;
>> + return 0;
>>
>> + /* Locate desired compression method. */
>> for (step = zbackends; step->name; step++) {
>> if (!strcmp(compress, step->name)) {
>> zbackend = step;
>> - pr_info("using %s compression\n", zbackend->name);
>> - return;
>> + break;
>> }
>> }
>> -}
>>
>> -static int __init pstore_compression_late_init(void)
>> -{
>> /*
>> - * Check if any pstore backends registered earlier but did not allocate
>> - * for compression because crypto was not ready, if so then initialize
>> - * compression.
>> + * Check if any pstore backends registered earlier but did not
>> + * initialize compression because crypto was not ready. If so,
>> + * then initialize compression now.
>> */
>> - if (psinfo && !tfm)
>> - allocate_buf_for_compression();
>> + allocate_buf_for_compression();
>
> We can also get rid of the 'zbackend' global variable since choosing the
> compression backend and allocating the buffers are done at the same time?
>
> Otherwise looks good to me,
>
> Reviewed-by: Joel Fernandes (Google) <[email protected]>
>
Tested this on top of Joel's patch, works fine on getting early crash
pstore dmesg logs, thanks.
Tested-by: Sai Prakash Ranjan <[email protected]>
--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation
On Wed, Oct 17, 2018 at 6:30 PM, Joel Fernandes <[email protected]> wrote:
> On Wed, Oct 17, 2018 at 02:41:24PM -0700, Kees Cook wrote:
>> With compression initialization now separated from pstore_register(),
>> there is no longer a good reason to do compression method selection
>> during fs init. Instead, merge everything together into the late init.
>> Additionally cleans up the reporting to be more clear.
>>
>> Signed-off-by: Kees Cook <[email protected]>
>> ---
>> This patch goes on top of Joel's. I'll have both in linux-next shortly...
>> ---
>> fs/pstore/inode.c | 2 --
>> fs/pstore/internal.h | 3 --
>> fs/pstore/platform.c | 65 ++++++++++++++++++++++++++++----------------
>> 3 files changed, 41 insertions(+), 29 deletions(-)
>>
>> diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
>> index 5fcb845b9fec..d814723fb27d 100644
>> --- a/fs/pstore/inode.c
>> +++ b/fs/pstore/inode.c
>> @@ -486,8 +486,6 @@ static int __init init_pstore_fs(void)
>> {
>> int err;
>>
>> - pstore_choose_compression();
>> -
>> /* Create a convenient mount point for people to access pstore */
>> err = sysfs_create_mount_point(fs_kobj, "pstore");
>> if (err)
>> diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h
>> index fb767e28aeb2..c029314478fa 100644
>> --- a/fs/pstore/internal.h
>> +++ b/fs/pstore/internal.h
>> @@ -37,7 +37,4 @@ extern bool pstore_is_mounted(void);
>> extern void pstore_record_init(struct pstore_record *record,
>> struct pstore_info *psi);
>>
>> -/* Called during module_init() */
>> -extern void __init pstore_choose_compression(void);
>> -
>> #endif
>> diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
>> index f09066db2d4d..e4737a5fa68c 100644
>> --- a/fs/pstore/platform.c
>> +++ b/fs/pstore/platform.c
>> @@ -274,36 +274,56 @@ static int pstore_decompress(void *in, void *out,
>>
>> static void allocate_buf_for_compression(void)
>> {
>> + struct crypto_comp *ctx;
>> + int size;
>> + char *buf;
>> +
>> + /* Skip if not built-in or compression backend not selected yet. */
>> if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !zbackend)
>> return;
>>
>> + /* Skip if no pstore backend yet or compression init already done. */
>> + if (!psinfo || tfm)
>> + return;
>> +
>> if (!crypto_has_comp(zbackend->name, 0, 0)) {
>> - pr_err("No %s compression\n", zbackend->name);
>> + pr_err("Unknown compression: %s\n", zbackend->name);
>> return;
>> }
>>
>> - big_oops_buf_sz = zbackend->zbufsize(psinfo->bufsize);
>> - if (big_oops_buf_sz <= 0)
>> + size = zbackend->zbufsize(psinfo->bufsize);
>> + if (size <= 0) {
>> + pr_err("Invalid compression size for %s: %d\n",
>> + zbackend->name, size);
>> return;
>> + }
>>
>> - big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
>> - if (!big_oops_buf) {
>> - pr_err("allocate compression buffer error!\n");
>> + buf = kmalloc(size, GFP_KERNEL);
>> + if (!buf) {
>> + pr_err("Failed %d byte compression buffer allocation for: %s\n",
>> + size, zbackend->name);
>> return;
>> }
>>
>> - tfm = crypto_alloc_comp(zbackend->name, 0, 0);
>> - if (IS_ERR_OR_NULL(tfm)) {
>> - kfree(big_oops_buf);
>> - big_oops_buf = NULL;
>> - pr_err("crypto_alloc_comp() failed!\n");
>> + ctx = crypto_alloc_comp(zbackend->name, 0, 0);
>> + if (IS_ERR_OR_NULL(ctx)) {
>> + kfree(buf);
>> + pr_err("crypto_alloc_comp('%s') failed: %ld\n", zbackend->name,
>> + PTR_ERR(ctx));
>> return;
>> }
>> +
>> + /* A non-NULL big_oops_buf indicates compression is available. */
>> + tfm = ctx;
>> + big_oops_buf_sz = size;
>> + big_oops_buf = buf;
>> +
>> + pr_info("Using compression: %s\n", zbackend->name);
>> }
>>
>> static void free_buf_for_compression(void)
>> {
>> - if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && !IS_ERR_OR_NULL(tfm))
>> + if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && tfm)
>> crypto_free_comp(tfm);
>> kfree(big_oops_buf);
>> big_oops_buf = NULL;
>> @@ -764,31 +784,28 @@ static void pstore_timefunc(struct timer_list *unused)
>> jiffies + msecs_to_jiffies(pstore_update_ms));
>> }
>>
>> -void __init pstore_choose_compression(void)
>> +static int __init pstore_compression_late_init(void)
>> {
>> const struct pstore_zbackend *step;
>>
>> if (!compress)
>> - return;
>> + return 0;
>>
>> + /* Locate desired compression method. */
>> for (step = zbackends; step->name; step++) {
>> if (!strcmp(compress, step->name)) {
>> zbackend = step;
>> - pr_info("using %s compression\n", zbackend->name);
>> - return;
>> + break;
>> }
>> }
>> -}
>>
>> -static int __init pstore_compression_late_init(void)
>> -{
>> /*
>> - * Check if any pstore backends registered earlier but did not allocate
>> - * for compression because crypto was not ready, if so then initialize
>> - * compression.
>> + * Check if any pstore backends registered earlier but did not
>> + * initialize compression because crypto was not ready. If so,
>> + * then initialize compression now.
>> */
>> - if (psinfo && !tfm)
>> - allocate_buf_for_compression();
>> + allocate_buf_for_compression();
>
> We can also get rid of the 'zbackend' global variable since choosing the
> compression backend and allocating the buffers are done at the same time?
That's my intention once I push the zbufsize functions up into the
crypto subsystem (there's a separate series for this that I need to
refresh).
> Otherwise looks good to me,
>
> Reviewed-by: Joel Fernandes (Google) <[email protected]>
Thanks!
-Kees
--
Kees Cook
Pixel Security
On Wed, Oct 17, 2018 at 9:42 PM, Sai Prakash Ranjan
<[email protected]> wrote:
> On 10/18/2018 7:00 AM, Joel Fernandes wrote:
> On Wed, Oct 17, 2018 at 02:41:24PM -0700, Kees Cook wrote:
>>>
>>> With compression initialization now separated from pstore_register(),
>>> there is no longer a good reason to do compression method selection
>>> during fs init. Instead, merge everything together into the late init.
>>> Additionally cleans up the reporting to be more clear.
>>>
>>> Signed-off-by: Kees Cook <[email protected]>
>>> ---
>>> This patch goes on top of Joel's. I'll have both in linux-next shortly...
>>> ---
>>> fs/pstore/inode.c | 2 --
>>> fs/pstore/internal.h | 3 --
>>> fs/pstore/platform.c | 65 ++++++++++++++++++++++++++++----------------
>>> 3 files changed, 41 insertions(+), 29 deletions(-)
>>>
>>> diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c
>>> index 5fcb845b9fec..d814723fb27d 100644
>>> --- a/fs/pstore/inode.c
>>> +++ b/fs/pstore/inode.c
>>> @@ -486,8 +486,6 @@ static int __init init_pstore_fs(void)
>>> {
>>> int err;
>>> - pstore_choose_compression();
>>> -
>>> /* Create a convenient mount point for people to access pstore */
>>> err = sysfs_create_mount_point(fs_kobj, "pstore");
>>> if (err)
>>> diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h
>>> index fb767e28aeb2..c029314478fa 100644
>>> --- a/fs/pstore/internal.h
>>> +++ b/fs/pstore/internal.h
>>> @@ -37,7 +37,4 @@ extern bool pstore_is_mounted(void);
>>> extern void pstore_record_init(struct pstore_record *record,
>>> struct pstore_info *psi);
>>> -/* Called during module_init() */
>>> -extern void __init pstore_choose_compression(void);
>>> -
>>> #endif
>>> diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
>>> index f09066db2d4d..e4737a5fa68c 100644
>>> --- a/fs/pstore/platform.c
>>> +++ b/fs/pstore/platform.c
>>> @@ -274,36 +274,56 @@ static int pstore_decompress(void *in, void *out,
>>> static void allocate_buf_for_compression(void)
>>> {
>>> + struct crypto_comp *ctx;
>>> + int size;
>>> + char *buf;
>>> +
>>> + /* Skip if not built-in or compression backend not selected yet.
>>> */
>>> if (!IS_ENABLED(CONFIG_PSTORE_COMPRESS) || !zbackend)
>>> return;
>>> + /* Skip if no pstore backend yet or compression init already
>>> done. */
>>> + if (!psinfo || tfm)
>>> + return;
>>> +
>>> if (!crypto_has_comp(zbackend->name, 0, 0)) {
>>> - pr_err("No %s compression\n", zbackend->name);
>>> + pr_err("Unknown compression: %s\n", zbackend->name);
>>> return;
>>> }
>>> - big_oops_buf_sz = zbackend->zbufsize(psinfo->bufsize);
>>> - if (big_oops_buf_sz <= 0)
>>> + size = zbackend->zbufsize(psinfo->bufsize);
>>> + if (size <= 0) {
>>> + pr_err("Invalid compression size for %s: %d\n",
>>> + zbackend->name, size);
>>> return;
>>> + }
>>> - big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
>>> - if (!big_oops_buf) {
>>> - pr_err("allocate compression buffer error!\n");
>>> + buf = kmalloc(size, GFP_KERNEL);
>>> + if (!buf) {
>>> + pr_err("Failed %d byte compression buffer allocation for:
>>> %s\n",
>>> + size, zbackend->name);
>>> return;
>>> }
>>> - tfm = crypto_alloc_comp(zbackend->name, 0, 0);
>>> - if (IS_ERR_OR_NULL(tfm)) {
>>> - kfree(big_oops_buf);
>>> - big_oops_buf = NULL;
>>> - pr_err("crypto_alloc_comp() failed!\n");
>>> + ctx = crypto_alloc_comp(zbackend->name, 0, 0);
>>> + if (IS_ERR_OR_NULL(ctx)) {
>>> + kfree(buf);
>>> + pr_err("crypto_alloc_comp('%s') failed: %ld\n",
>>> zbackend->name,
>>> + PTR_ERR(ctx));
>>> return;
>>> }
>>> +
>>> + /* A non-NULL big_oops_buf indicates compression is available. */
>>> + tfm = ctx;
>>> + big_oops_buf_sz = size;
>>> + big_oops_buf = buf;
>>> +
>>> + pr_info("Using compression: %s\n", zbackend->name);
>>> }
>>> static void free_buf_for_compression(void)
>>> {
>>> - if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && !IS_ERR_OR_NULL(tfm))
>>> + if (IS_ENABLED(CONFIG_PSTORE_COMPRESS) && tfm)
>>> crypto_free_comp(tfm);
>>> kfree(big_oops_buf);
>>> big_oops_buf = NULL;
>>> @@ -764,31 +784,28 @@ static void pstore_timefunc(struct timer_list
>>> *unused)
>>> jiffies + msecs_to_jiffies(pstore_update_ms));
>>> }
>>> -void __init pstore_choose_compression(void)
>>> +static int __init pstore_compression_late_init(void)
>>> {
>>> const struct pstore_zbackend *step;
>>> if (!compress)
>>> - return;
>>> + return 0;
>>> + /* Locate desired compression method. */
>>> for (step = zbackends; step->name; step++) {
>>> if (!strcmp(compress, step->name)) {
>>> zbackend = step;
>>> - pr_info("using %s compression\n",
>>> zbackend->name);
>>> - return;
>>> + break;
>>> }
>>> }
>>> -}
>>> -static int __init pstore_compression_late_init(void)
>>> -{
>>> /*
>>> - * Check if any pstore backends registered earlier but did not
>>> allocate
>>> - * for compression because crypto was not ready, if so then
>>> initialize
>>> - * compression.
>>> + * Check if any pstore backends registered earlier but did not
>>> + * initialize compression because crypto was not ready. If so,
>>> + * then initialize compression now.
>>> */
>>> - if (psinfo && !tfm)
>>> - allocate_buf_for_compression();
>>> + allocate_buf_for_compression();
>>
>>
>> We can also get rid of the 'zbackend' global variable since choosing the
>> compression backend and allocating the buffers are done at the same time?
>>
>> Otherwise looks good to me,
>>
>> Reviewed-by: Joel Fernandes (Google) <[email protected]>
>>
>
> Tested this on top of Joel's patch, works fine on getting early crash pstore
> dmesg logs, thanks.
>
> Tested-by: Sai Prakash Ranjan <[email protected]>
Awesome! Thanks for testing it. :)
-Kees
--
Kees Cook
Pixel Security
On Wed, 2018-10-17 at 14:41 -0700, Kees Cook wrote:
> With compression initialization now separated from pstore_register(),
> there is no longer a good reason to do compression method selection
> during fs init. Instead, merge everything together into the late init.
> Additionally cleans up the reporting to be more clear.
[]
> diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
[]
> @@ -274,36 +274,56 @@ static int pstore_decompress(void *in, void *out,
[]
> - big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
> - if (!big_oops_buf) {
> - pr_err("allocate compression buffer error!\n");
> + buf = kmalloc(size, GFP_KERNEL);
> + if (!buf) {
> + pr_err("Failed %d byte compression buffer allocation for: %s\n",
> + size, zbackend->name);
Given that there is a generic OOM message emitted on
kmalloc failures, rather than expanding the unnecessary
alloc failure message, how about just deleting it instead?
On Thu, Oct 18, 2018 at 10:14 AM, Joe Perches <[email protected]> wrote:
> On Wed, 2018-10-17 at 14:41 -0700, Kees Cook wrote:
>> With compression initialization now separated from pstore_register(),
>> there is no longer a good reason to do compression method selection
>> during fs init. Instead, merge everything together into the late init.
>> Additionally cleans up the reporting to be more clear.
> []
>> diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
> []
>> @@ -274,36 +274,56 @@ static int pstore_decompress(void *in, void *out,
> []
>> - big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL);
>> - if (!big_oops_buf) {
>> - pr_err("allocate compression buffer error!\n");
>> + buf = kmalloc(size, GFP_KERNEL);
>> + if (!buf) {
>> + pr_err("Failed %d byte compression buffer allocation for: %s\n",
>> + size, zbackend->name);
>
> Given that there is a generic OOM message emitted on
> kmalloc failures, rather than expanding the unnecessary
> alloc failure message, how about just deleting it instead?
I prefer including more context (i.e. the desired compression method).
-Kees
--
Kees Cook
Pixel Security