* [PATCH][next] wifi: mt76: mt7921: Replace fake flex-arrays with flexible-array members
@ 2023-03-17 20:56 Gustavo A. R. Silva
2023-03-20 14:56 ` Simon Horman
2023-03-30 20:11 ` Gustavo A. R. Silva
0 siblings, 2 replies; 5+ messages in thread
From: Gustavo A. R. Silva @ 2023-03-17 20:56 UTC (permalink / raw)
To: Felix Fietkau, Lorenzo Bianconi, Ryder Lee, Shayne Chen,
Sean Wang, Kalle Valo, David S. Miller, Eric Dumazet,
Jakub Kicinski, Paolo Abeni, Matthias Brugger,
AngeloGioacchino Del Regno
Cc: linux-wireless, netdev, linux-kernel, linux-arm-kernel,
linux-mediatek, Gustavo A. R. Silva, linux-hardening
Zero-length arrays as fake flexible arrays are deprecated and we are
moving towards adopting C99 flexible-array members instead.
Address the following warnings found with GCC-13 and
-fstrict-flex-arrays=3 enabled:
drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:266:25: warning: array subscript 0 is outside array bounds of ‘struct mt7921_asar_dyn_limit_v2[0]’ [-Warray-bounds=]
drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:263:25: warning: array subscript 0 is outside array bounds of ‘struct mt7921_asar_dyn_limit[0]’ [-Warray-bounds=]
drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:223:28: warning: array subscript <unknown> is outside array bounds of ‘struct mt7921_asar_geo_limit_v2[0]’ [-Warray-bounds=]
drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:220:28: warning: array subscript <unknown> is outside array bounds of ‘struct mt7921_asar_geo_limit[0]’ [-Warray-bounds=]
drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:334:37: warning: array subscript i is outside array bounds of ‘u8[0]’ {aka ‘unsigned char[]’} [-Warray-bounds=]
Notice that the DECLARE_FLEX_ARRAY() helper allows for flexible-array
members in unions.
This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
routines on memcpy() and help us make progress towards globally
enabling -fstrict-flex-arrays=3 [1].
Link: https://github.com/KSPP/linux/issues/21
Link: https://github.com/KSPP/linux/issues/272
Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.h | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.h b/drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.h
index 35268b0890ad..6f2c4a572572 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.h
+++ b/drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.h
@@ -24,7 +24,7 @@ struct mt7921_asar_dyn {
u8 names[4];
u8 enable;
u8 nr_tbl;
- struct mt7921_asar_dyn_limit tbl[0];
+ DECLARE_FLEX_ARRAY(struct mt7921_asar_dyn_limit, tbl);
} __packed;
struct mt7921_asar_dyn_limit_v2 {
@@ -37,7 +37,7 @@ struct mt7921_asar_dyn_v2 {
u8 enable;
u8 rsvd;
u8 nr_tbl;
- struct mt7921_asar_dyn_limit_v2 tbl[0];
+ DECLARE_FLEX_ARRAY(struct mt7921_asar_dyn_limit_v2, tbl);
} __packed;
struct mt7921_asar_geo_band {
@@ -55,7 +55,7 @@ struct mt7921_asar_geo {
u8 names[4];
u8 version;
u8 nr_tbl;
- struct mt7921_asar_geo_limit tbl[0];
+ DECLARE_FLEX_ARRAY(struct mt7921_asar_geo_limit, tbl);
} __packed;
struct mt7921_asar_geo_limit_v2 {
@@ -69,7 +69,7 @@ struct mt7921_asar_geo_v2 {
u8 version;
u8 rsvd;
u8 nr_tbl;
- struct mt7921_asar_geo_limit_v2 tbl[0];
+ DECLARE_FLEX_ARRAY(struct mt7921_asar_geo_limit_v2, tbl);
} __packed;
struct mt7921_asar_cl {
@@ -85,7 +85,7 @@ struct mt7921_asar_fg {
u8 rsvd;
u8 nr_flag;
u8 rsvd1;
- u8 flag[0];
+ u8 flag[];
} __packed;
struct mt7921_acpi_sar {
--
2.34.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH][next] wifi: mt76: mt7921: Replace fake flex-arrays with flexible-array members
2023-03-17 20:56 [PATCH][next] wifi: mt76: mt7921: Replace fake flex-arrays with flexible-array members Gustavo A. R. Silva
@ 2023-03-20 14:56 ` Simon Horman
2023-03-20 19:26 ` Gustavo A. R. Silva
2023-03-30 20:11 ` Gustavo A. R. Silva
1 sibling, 1 reply; 5+ messages in thread
From: Simon Horman @ 2023-03-20 14:56 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Felix Fietkau, Lorenzo Bianconi, Ryder Lee, Shayne Chen,
Sean Wang, Kalle Valo, David S. Miller, Eric Dumazet,
Jakub Kicinski, Paolo Abeni, Matthias Brugger,
AngeloGioacchino Del Regno, linux-wireless, netdev, linux-kernel,
linux-arm-kernel, linux-mediatek, linux-hardening
On Fri, Mar 17, 2023 at 02:56:39PM -0600, Gustavo A. R. Silva wrote:
> Zero-length arrays as fake flexible arrays are deprecated and we are
> moving towards adopting C99 flexible-array members instead.
>
> Address the following warnings found with GCC-13 and
> -fstrict-flex-arrays=3 enabled:
> drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:266:25: warning: array subscript 0 is outside array bounds of ‘struct mt7921_asar_dyn_limit_v2[0]’ [-Warray-bounds=]
> drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:263:25: warning: array subscript 0 is outside array bounds of ‘struct mt7921_asar_dyn_limit[0]’ [-Warray-bounds=]
> drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:223:28: warning: array subscript <unknown> is outside array bounds of ‘struct mt7921_asar_geo_limit_v2[0]’ [-Warray-bounds=]
> drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:220:28: warning: array subscript <unknown> is outside array bounds of ‘struct mt7921_asar_geo_limit[0]’ [-Warray-bounds=]
> drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:334:37: warning: array subscript i is outside array bounds of ‘u8[0]’ {aka ‘unsigned char[]’} [-Warray-bounds=]
>
> Notice that the DECLARE_FLEX_ARRAY() helper allows for flexible-array
> members in unions.
>
> This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
> routines on memcpy() and help us make progress towards globally
> enabling -fstrict-flex-arrays=3 [1].
>
> Link: https://github.com/KSPP/linux/issues/21
> Link: https://github.com/KSPP/linux/issues/272
> Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
> drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.h | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.h b/drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.h
> index 35268b0890ad..6f2c4a572572 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.h
> +++ b/drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.h
...
> @@ -69,7 +69,7 @@ struct mt7921_asar_geo_v2 {
> u8 version;
> u8 rsvd;
> u8 nr_tbl;
> - struct mt7921_asar_geo_limit_v2 tbl[0];
> + DECLARE_FLEX_ARRAY(struct mt7921_asar_geo_limit_v2, tbl);
> } __packed;
>
> struct mt7921_asar_cl {
> @@ -85,7 +85,7 @@ struct mt7921_asar_fg {
> u8 rsvd;
> u8 nr_flag;
> u8 rsvd1;
> - u8 flag[0];
> + u8 flag[];
I am curious to know why DECLARE_FLEX_ARRAY isn't used here.
> } __packed;
>
> struct mt7921_acpi_sar {
> --
> 2.34.1
>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH][next] wifi: mt76: mt7921: Replace fake flex-arrays with flexible-array members
2023-03-20 14:56 ` Simon Horman
@ 2023-03-20 19:26 ` Gustavo A. R. Silva
2023-03-20 19:48 ` Simon Horman
0 siblings, 1 reply; 5+ messages in thread
From: Gustavo A. R. Silva @ 2023-03-20 19:26 UTC (permalink / raw)
To: Simon Horman
Cc: Felix Fietkau, Lorenzo Bianconi, Ryder Lee, Shayne Chen,
Sean Wang, Kalle Valo, David S. Miller, Eric Dumazet,
Jakub Kicinski, Paolo Abeni, Matthias Brugger,
AngeloGioacchino Del Regno, linux-wireless, netdev, linux-kernel,
linux-arm-kernel, linux-mediatek, linux-hardening
On Mon, Mar 20, 2023 at 03:56:54PM +0100, Simon Horman wrote:
> > struct mt7921_asar_cl {
> > @@ -85,7 +85,7 @@ struct mt7921_asar_fg {
> > u8 rsvd;
> > u8 nr_flag;
> > u8 rsvd1;
> > - u8 flag[0];
> > + u8 flag[];
>
> I am curious to know why DECLARE_FLEX_ARRAY isn't used here.
In contrast to the other structs, there is no object of type struct
mt7921_asar_fg declared in a union:
91 struct mt7921_acpi_sar {
92 u8 ver;
93 union {
94 struct mt7921_asar_dyn *dyn;
95 struct mt7921_asar_dyn_v2 *dyn_v2;
96 };
97 union {
98 struct mt7921_asar_geo *geo;
99 struct mt7921_asar_geo_v2 *geo_v2;
100 };
101 struct mt7921_asar_cl *countrylist;
102 struct mt7921_asar_fg *fg;
103 };
The DECLARE_FLEX_ARRAY() helper was created to declare flex-array members
in unions or alone in structs[1].
--
Gustavo
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH][next] wifi: mt76: mt7921: Replace fake flex-arrays with flexible-array members
2023-03-20 19:26 ` Gustavo A. R. Silva
@ 2023-03-20 19:48 ` Simon Horman
0 siblings, 0 replies; 5+ messages in thread
From: Simon Horman @ 2023-03-20 19:48 UTC (permalink / raw)
To: Gustavo A. R. Silva
Cc: Felix Fietkau, Lorenzo Bianconi, Ryder Lee, Shayne Chen,
Sean Wang, Kalle Valo, David S. Miller, Eric Dumazet,
Jakub Kicinski, Paolo Abeni, Matthias Brugger,
AngeloGioacchino Del Regno, linux-wireless, netdev, linux-kernel,
linux-arm-kernel, linux-mediatek, linux-hardening
On Mon, Mar 20, 2023 at 01:26:49PM -0600, Gustavo A. R. Silva wrote:
> On Mon, Mar 20, 2023 at 03:56:54PM +0100, Simon Horman wrote:
> > > struct mt7921_asar_cl {
> > > @@ -85,7 +85,7 @@ struct mt7921_asar_fg {
> > > u8 rsvd;
> > > u8 nr_flag;
> > > u8 rsvd1;
> > > - u8 flag[0];
> > > + u8 flag[];
> >
> > I am curious to know why DECLARE_FLEX_ARRAY isn't used here.
>
> In contrast to the other structs, there is no object of type struct
> mt7921_asar_fg declared in a union:
>
> 91 struct mt7921_acpi_sar {
> 92 u8 ver;
> 93 union {
> 94 struct mt7921_asar_dyn *dyn;
> 95 struct mt7921_asar_dyn_v2 *dyn_v2;
> 96 };
> 97 union {
> 98 struct mt7921_asar_geo *geo;
> 99 struct mt7921_asar_geo_v2 *geo_v2;
> 100 };
> 101 struct mt7921_asar_cl *countrylist;
> 102 struct mt7921_asar_fg *fg;
> 103 };
>
> The DECLARE_FLEX_ARRAY() helper was created to declare flex-array members
> in unions or alone in structs[1].
Thanks for the clarification, much appreciated.
FWIIW, with this information I'm happy with this patch.
Reviewed-by: Simon Horman <simon.horman@corigine.com>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH][next] wifi: mt76: mt7921: Replace fake flex-arrays with flexible-array members
2023-03-17 20:56 [PATCH][next] wifi: mt76: mt7921: Replace fake flex-arrays with flexible-array members Gustavo A. R. Silva
2023-03-20 14:56 ` Simon Horman
@ 2023-03-30 20:11 ` Gustavo A. R. Silva
1 sibling, 0 replies; 5+ messages in thread
From: Gustavo A. R. Silva @ 2023-03-30 20:11 UTC (permalink / raw)
To: Gustavo A. R. Silva, Felix Fietkau, Lorenzo Bianconi, Ryder Lee,
Shayne Chen, Sean Wang, Kalle Valo, David S. Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, Matthias Brugger,
AngeloGioacchino Del Regno
Cc: linux-wireless, netdev, linux-kernel, linux-arm-kernel,
linux-mediatek, linux-hardening
Hi all,
Friendly ping: who can take this, please? 😄
Thanks
--
Gustavo
On 3/17/23 14:56, Gustavo A. R. Silva wrote:
> Zero-length arrays as fake flexible arrays are deprecated and we are
> moving towards adopting C99 flexible-array members instead.
>
> Address the following warnings found with GCC-13 and
> -fstrict-flex-arrays=3 enabled:
> drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:266:25: warning: array subscript 0 is outside array bounds of ‘struct mt7921_asar_dyn_limit_v2[0]’ [-Warray-bounds=]
> drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:263:25: warning: array subscript 0 is outside array bounds of ‘struct mt7921_asar_dyn_limit[0]’ [-Warray-bounds=]
> drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:223:28: warning: array subscript <unknown> is outside array bounds of ‘struct mt7921_asar_geo_limit_v2[0]’ [-Warray-bounds=]
> drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:220:28: warning: array subscript <unknown> is outside array bounds of ‘struct mt7921_asar_geo_limit[0]’ [-Warray-bounds=]
> drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.c:334:37: warning: array subscript i is outside array bounds of ‘u8[0]’ {aka ‘unsigned char[]’} [-Warray-bounds=]
>
> Notice that the DECLARE_FLEX_ARRAY() helper allows for flexible-array
> members in unions.
>
> This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
> routines on memcpy() and help us make progress towards globally
> enabling -fstrict-flex-arrays=3 [1].
>
> Link: https://github.com/KSPP/linux/issues/21
> Link: https://github.com/KSPP/linux/issues/272
> Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
> ---
> drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.h | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.h b/drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.h
> index 35268b0890ad..6f2c4a572572 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.h
> +++ b/drivers/net/wireless/mediatek/mt76/mt7921/acpi_sar.h
> @@ -24,7 +24,7 @@ struct mt7921_asar_dyn {
> u8 names[4];
> u8 enable;
> u8 nr_tbl;
> - struct mt7921_asar_dyn_limit tbl[0];
> + DECLARE_FLEX_ARRAY(struct mt7921_asar_dyn_limit, tbl);
> } __packed;
>
> struct mt7921_asar_dyn_limit_v2 {
> @@ -37,7 +37,7 @@ struct mt7921_asar_dyn_v2 {
> u8 enable;
> u8 rsvd;
> u8 nr_tbl;
> - struct mt7921_asar_dyn_limit_v2 tbl[0];
> + DECLARE_FLEX_ARRAY(struct mt7921_asar_dyn_limit_v2, tbl);
> } __packed;
>
> struct mt7921_asar_geo_band {
> @@ -55,7 +55,7 @@ struct mt7921_asar_geo {
> u8 names[4];
> u8 version;
> u8 nr_tbl;
> - struct mt7921_asar_geo_limit tbl[0];
> + DECLARE_FLEX_ARRAY(struct mt7921_asar_geo_limit, tbl);
> } __packed;
>
> struct mt7921_asar_geo_limit_v2 {
> @@ -69,7 +69,7 @@ struct mt7921_asar_geo_v2 {
> u8 version;
> u8 rsvd;
> u8 nr_tbl;
> - struct mt7921_asar_geo_limit_v2 tbl[0];
> + DECLARE_FLEX_ARRAY(struct mt7921_asar_geo_limit_v2, tbl);
> } __packed;
>
> struct mt7921_asar_cl {
> @@ -85,7 +85,7 @@ struct mt7921_asar_fg {
> u8 rsvd;
> u8 nr_flag;
> u8 rsvd1;
> - u8 flag[0];
> + u8 flag[];
> } __packed;
>
> struct mt7921_acpi_sar {
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2023-03-31 1:18 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2023-03-17 20:56 [PATCH][next] wifi: mt76: mt7921: Replace fake flex-arrays with flexible-array members Gustavo A. R. Silva
2023-03-20 14:56 ` Simon Horman
2023-03-20 19:26 ` Gustavo A. R. Silva
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