* [PATCH] tunables: Fix comparison of tunable values
@ 2021-03-16 13:34 Siddhesh Poyarekar
2021-03-22 4:28 ` [PING][PATCH] " Siddhesh Poyarekar
2021-04-06 19:50 ` [PATCH] " Carlos O'Donell
0 siblings, 2 replies; 3+ messages in thread
From: Siddhesh Poyarekar @ 2021-03-16 13:34 UTC (permalink / raw)
To: libc-alpha
The simplification of tunable_set interfaces took care of
signed/unsigned conversions while setting values, but comparison with
bounds ended up being incorrect; comparing TUNABLE_SIZE_T values for
example will fail because SIZE_MAX is seen as -1.
Add comparison helpers that take tunable types into account and use
them to do comparison instead.
---
elf/dl-tunable-types.h | 17 +++++++++++++++++
elf/dl-tunables.c | 25 ++++++++++++++-----------
elf/dl-tunables.h | 18 ++++++++++++++++++
3 files changed, 49 insertions(+), 11 deletions(-)
diff --git a/elf/dl-tunable-types.h b/elf/dl-tunable-types.h
index 626ca334be..39bf738d93 100644
--- a/elf/dl-tunable-types.h
+++ b/elf/dl-tunable-types.h
@@ -81,4 +81,21 @@ struct _tunable
typedef struct _tunable tunable_t;
+static __always_inline bool
+unsigned_tunable_type (tunable_type_code_t t)
+{
+ switch (t)
+ {
+ case TUNABLE_TYPE_INT_32:
+ return false;
+ case TUNABLE_TYPE_UINT_64:
+ case TUNABLE_TYPE_SIZE_T:
+ return true;
+ case TUNABLE_TYPE_STRING:
+ default:
+ break;
+ }
+ __builtin_unreachable ();
+}
+
#endif
diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c
index 1aedb9bd36..8009e54ee5 100644
--- a/elf/dl-tunables.c
+++ b/elf/dl-tunables.c
@@ -107,32 +107,35 @@ do_tunable_update_val (tunable_t *cur, const tunable_val_t *valp,
return;
}
+ bool unsigned_cmp = unsigned_tunable_type (cur->type.type_code);
+
val = valp->numval;
min = minp != NULL ? *minp : cur->type.min;
max = maxp != NULL ? *maxp : cur->type.max;
/* We allow only increasingly restrictive bounds. */
- if (min < cur->type.min)
+ if (tunable_val_lt (min, cur->type.min, unsigned_cmp))
min = cur->type.min;
- if (max > cur->type.max)
+ if (tunable_val_gt (max, cur->type.max, unsigned_cmp))
max = cur->type.max;
/* Skip both bounds if they're inconsistent. */
- if (min > max)
+ if (tunable_val_gt (min, max, unsigned_cmp))
{
min = cur->type.min;
max = cur->type.max;
}
- /* Write everything out if the value and the bounds are valid. */
- if (min <= val && val <= max)
- {
- cur->val.numval = val;
- cur->type.min = min;
- cur->type.max = max;
- cur->initialized = true;
- }
+ /* Bail out if the bounds are not valid. */
+ if (tunable_val_lt (val, min, unsigned_cmp)
+ || tunable_val_lt (max, val, unsigned_cmp))
+ return;
+
+ cur->val.numval = val;
+ cur->type.min = min;
+ cur->type.max = max;
+ cur->initialized = true;
}
/* Validate range of the input value and initialize the tunable CUR if it looks
diff --git a/elf/dl-tunables.h b/elf/dl-tunables.h
index ba7ae6b52e..3880e4aab6 100644
--- a/elf/dl-tunables.h
+++ b/elf/dl-tunables.h
@@ -115,6 +115,24 @@ rtld_hidden_proto (__tunable_set_val)
/* The default value for TUNABLES_FRONTEND. */
# define TUNABLES_FRONTEND_yes TUNABLES_FRONTEND_valstring
+static __always_inline bool
+tunable_val_lt (tunable_num_t lhs, tunable_num_t rhs, bool unsigned_cmp)
+{
+ if (unsigned_cmp)
+ return (uintmax_t) lhs < (uintmax_t) rhs;
+ else
+ return lhs < rhs;
+}
+
+static __always_inline bool
+tunable_val_gt (tunable_num_t lhs, tunable_num_t rhs, bool unsigned_cmp)
+{
+ if (unsigned_cmp)
+ return (uintmax_t) lhs > (uintmax_t) rhs;
+ else
+ return lhs > rhs;
+}
+
/* Compare two name strings, bounded by the name hardcoded in glibc. */
static __always_inline bool
tunable_is_name (const char *orig, const char *envname)
--
2.29.2
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PING][PATCH] tunables: Fix comparison of tunable values
2021-03-16 13:34 [PATCH] tunables: Fix comparison of tunable values Siddhesh Poyarekar
@ 2021-03-22 4:28 ` Siddhesh Poyarekar
2021-04-06 19:50 ` [PATCH] " Carlos O'Donell
1 sibling, 0 replies; 3+ messages in thread
From: Siddhesh Poyarekar @ 2021-03-22 4:28 UTC (permalink / raw)
To: libc-alpha
On 3/16/21 7:04 PM, Siddhesh Poyarekar via Libc-alpha wrote:
> The simplification of tunable_set interfaces took care of
> signed/unsigned conversions while setting values, but comparison with
> bounds ended up being incorrect; comparing TUNABLE_SIZE_T values for
> example will fail because SIZE_MAX is seen as -1.
>
> Add comparison helpers that take tunable types into account and use
> them to do comparison instead.
> ---
> elf/dl-tunable-types.h | 17 +++++++++++++++++
> elf/dl-tunables.c | 25 ++++++++++++++-----------
> elf/dl-tunables.h | 18 ++++++++++++++++++
> 3 files changed, 49 insertions(+), 11 deletions(-)
>
> diff --git a/elf/dl-tunable-types.h b/elf/dl-tunable-types.h
> index 626ca334be..39bf738d93 100644
> --- a/elf/dl-tunable-types.h
> +++ b/elf/dl-tunable-types.h
> @@ -81,4 +81,21 @@ struct _tunable
>
> typedef struct _tunable tunable_t;
>
> +static __always_inline bool
> +unsigned_tunable_type (tunable_type_code_t t)
> +{
> + switch (t)
> + {
> + case TUNABLE_TYPE_INT_32:
> + return false;
> + case TUNABLE_TYPE_UINT_64:
> + case TUNABLE_TYPE_SIZE_T:
> + return true;
> + case TUNABLE_TYPE_STRING:
> + default:
> + break;
> + }
> + __builtin_unreachable ();
> +}
> +
> #endif
> diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c
> index 1aedb9bd36..8009e54ee5 100644
> --- a/elf/dl-tunables.c
> +++ b/elf/dl-tunables.c
> @@ -107,32 +107,35 @@ do_tunable_update_val (tunable_t *cur, const tunable_val_t *valp,
> return;
> }
>
> + bool unsigned_cmp = unsigned_tunable_type (cur->type.type_code);
> +
> val = valp->numval;
> min = minp != NULL ? *minp : cur->type.min;
> max = maxp != NULL ? *maxp : cur->type.max;
>
> /* We allow only increasingly restrictive bounds. */
> - if (min < cur->type.min)
> + if (tunable_val_lt (min, cur->type.min, unsigned_cmp))
> min = cur->type.min;
>
> - if (max > cur->type.max)
> + if (tunable_val_gt (max, cur->type.max, unsigned_cmp))
> max = cur->type.max;
>
> /* Skip both bounds if they're inconsistent. */
> - if (min > max)
> + if (tunable_val_gt (min, max, unsigned_cmp))
> {
> min = cur->type.min;
> max = cur->type.max;
> }
>
> - /* Write everything out if the value and the bounds are valid. */
> - if (min <= val && val <= max)
> - {
> - cur->val.numval = val;
> - cur->type.min = min;
> - cur->type.max = max;
> - cur->initialized = true;
> - }
> + /* Bail out if the bounds are not valid. */
> + if (tunable_val_lt (val, min, unsigned_cmp)
> + || tunable_val_lt (max, val, unsigned_cmp))
> + return;
> +
> + cur->val.numval = val;
> + cur->type.min = min;
> + cur->type.max = max;
> + cur->initialized = true;
> }
>
> /* Validate range of the input value and initialize the tunable CUR if it looks
> diff --git a/elf/dl-tunables.h b/elf/dl-tunables.h
> index ba7ae6b52e..3880e4aab6 100644
> --- a/elf/dl-tunables.h
> +++ b/elf/dl-tunables.h
> @@ -115,6 +115,24 @@ rtld_hidden_proto (__tunable_set_val)
> /* The default value for TUNABLES_FRONTEND. */
> # define TUNABLES_FRONTEND_yes TUNABLES_FRONTEND_valstring
>
> +static __always_inline bool
> +tunable_val_lt (tunable_num_t lhs, tunable_num_t rhs, bool unsigned_cmp)
> +{
> + if (unsigned_cmp)
> + return (uintmax_t) lhs < (uintmax_t) rhs;
> + else
> + return lhs < rhs;
> +}
> +
> +static __always_inline bool
> +tunable_val_gt (tunable_num_t lhs, tunable_num_t rhs, bool unsigned_cmp)
> +{
> + if (unsigned_cmp)
> + return (uintmax_t) lhs > (uintmax_t) rhs;
> + else
> + return lhs > rhs;
> +}
> +
> /* Compare two name strings, bounded by the name hardcoded in glibc. */
> static __always_inline bool
> tunable_is_name (const char *orig, const char *envname)
>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] tunables: Fix comparison of tunable values
2021-03-16 13:34 [PATCH] tunables: Fix comparison of tunable values Siddhesh Poyarekar
2021-03-22 4:28 ` [PING][PATCH] " Siddhesh Poyarekar
@ 2021-04-06 19:50 ` Carlos O'Donell
1 sibling, 0 replies; 3+ messages in thread
From: Carlos O'Donell @ 2021-04-06 19:50 UTC (permalink / raw)
To: Siddhesh Poyarekar, libc-alpha
On 3/16/21 9:34 AM, Siddhesh Poyarekar via Libc-alpha wrote:
> The simplification of tunable_set interfaces took care of
> signed/unsigned conversions while setting values, but comparison with
> bounds ended up being incorrect; comparing TUNABLE_SIZE_T values for
> example will fail because SIZE_MAX is seen as -1.
>
> Add comparison helpers that take tunable types into account and use
> them to do comparison instead.
LGTM.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
> ---
> elf/dl-tunable-types.h | 17 +++++++++++++++++
> elf/dl-tunables.c | 25 ++++++++++++++-----------
> elf/dl-tunables.h | 18 ++++++++++++++++++
> 3 files changed, 49 insertions(+), 11 deletions(-)
>
> diff --git a/elf/dl-tunable-types.h b/elf/dl-tunable-types.h
> index 626ca334be..39bf738d93 100644
> --- a/elf/dl-tunable-types.h
> +++ b/elf/dl-tunable-types.h
> @@ -81,4 +81,21 @@ struct _tunable
>
> typedef struct _tunable tunable_t;
>
> +static __always_inline bool
> +unsigned_tunable_type (tunable_type_code_t t)
> +{
> + switch (t)
> + {
> + case TUNABLE_TYPE_INT_32:
> + return false;
> + case TUNABLE_TYPE_UINT_64:
> + case TUNABLE_TYPE_SIZE_T:
> + return true;
> + case TUNABLE_TYPE_STRING:
> + default:
> + break;
> + }
> + __builtin_unreachable ();
> +}
> +
OK.
> #endif
> diff --git a/elf/dl-tunables.c b/elf/dl-tunables.c
> index 1aedb9bd36..8009e54ee5 100644
> --- a/elf/dl-tunables.c
> +++ b/elf/dl-tunables.c
> @@ -107,32 +107,35 @@ do_tunable_update_val (tunable_t *cur, const tunable_val_t *valp,
> return;
> }
>
> + bool unsigned_cmp = unsigned_tunable_type (cur->type.type_code);
> +
> val = valp->numval;
> min = minp != NULL ? *minp : cur->type.min;
> max = maxp != NULL ? *maxp : cur->type.max;
>
> /* We allow only increasingly restrictive bounds. */
> - if (min < cur->type.min)
> + if (tunable_val_lt (min, cur->type.min, unsigned_cmp))
> min = cur->type.min;
>
> - if (max > cur->type.max)
> + if (tunable_val_gt (max, cur->type.max, unsigned_cmp))
> max = cur->type.max;
>
> /* Skip both bounds if they're inconsistent. */
> - if (min > max)
> + if (tunable_val_gt (min, max, unsigned_cmp))
OK.
> {
> min = cur->type.min;
> max = cur->type.max;
> }
>
> - /* Write everything out if the value and the bounds are valid. */
> - if (min <= val && val <= max)
> - {
> - cur->val.numval = val;
> - cur->type.min = min;
> - cur->type.max = max;
> - cur->initialized = true;
> - }
> + /* Bail out if the bounds are not valid. */
> + if (tunable_val_lt (val, min, unsigned_cmp)
> + || tunable_val_lt (max, val, unsigned_cmp))
> + return;
> +
> + cur->val.numval = val;
> + cur->type.min = min;
> + cur->type.max = max;
> + cur->initialized = true;
> }
>
> /* Validate range of the input value and initialize the tunable CUR if it looks
> diff --git a/elf/dl-tunables.h b/elf/dl-tunables.h
> index ba7ae6b52e..3880e4aab6 100644
> --- a/elf/dl-tunables.h
> +++ b/elf/dl-tunables.h
> @@ -115,6 +115,24 @@ rtld_hidden_proto (__tunable_set_val)
> /* The default value for TUNABLES_FRONTEND. */
> # define TUNABLES_FRONTEND_yes TUNABLES_FRONTEND_valstring
>
> +static __always_inline bool
> +tunable_val_lt (tunable_num_t lhs, tunable_num_t rhs, bool unsigned_cmp)
> +{
> + if (unsigned_cmp)
> + return (uintmax_t) lhs < (uintmax_t) rhs;
> + else
> + return lhs < rhs;
> +}
> +
> +static __always_inline bool
> +tunable_val_gt (tunable_num_t lhs, tunable_num_t rhs, bool unsigned_cmp)
> +{
> + if (unsigned_cmp)
> + return (uintmax_t) lhs > (uintmax_t) rhs;
> + else
> + return lhs > rhs;
> +}
> +
> /* Compare two name strings, bounded by the name hardcoded in glibc. */
> static __always_inline bool
> tunable_is_name (const char *orig, const char *envname)
>
--
Cheers,
Carlos.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-03-16 13:34 [PATCH] tunables: Fix comparison of tunable values Siddhesh Poyarekar
2021-03-22 4:28 ` [PING][PATCH] " Siddhesh Poyarekar
2021-04-06 19:50 ` [PATCH] " Carlos O'Donell
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