In preparation to enabling -Wvla, remove VLAs and replace them with
fixed-length arrays instead.
The arrays fixed here, using the number of constant sections, aren't
really VLAs, but they appear so to the compiler. Since we know at
build-time how many critical sections there are, we might as well use
a pre-processor-level constant instead.
This was prompted by https://lkml.org/lkml/2018/3/7/621
Signed-off-by: Stephen Kitt <[email protected]>
---
drivers/scsi/aic7xxx/aic79xx_core.c | 8 ++++----
drivers/scsi/aic7xxx/aic79xx_seq.h_shipped | 3 +--
drivers/scsi/aic7xxx/aic7xxx_core.c | 8 ++++----
drivers/scsi/aic7xxx/aic7xxx_seq.h_shipped | 3 +--
drivers/scsi/aic7xxx/aicasm/aicasm.c | 6 ++++--
5 files changed, 14 insertions(+), 14 deletions(-)
diff --git a/drivers/scsi/aic7xxx/aic79xx_core.c b/drivers/scsi/aic7xxx/aic79xx_core.c
index b560f396ee99..034f4eebb160 100644
--- a/drivers/scsi/aic7xxx/aic79xx_core.c
+++ b/drivers/scsi/aic7xxx/aic79xx_core.c
@@ -9338,9 +9338,9 @@ ahd_dumpseq(struct ahd_softc* ahd)
static void
ahd_loadseq(struct ahd_softc *ahd)
{
- struct cs cs_table[num_critical_sections];
- u_int begin_set[num_critical_sections];
- u_int end_set[num_critical_sections];
+ struct cs cs_table[NUM_CRITICAL_SECTIONS];
+ u_int begin_set[NUM_CRITICAL_SECTIONS];
+ u_int end_set[NUM_CRITICAL_SECTIONS];
const struct patch *cur_patch;
u_int cs_count;
u_int cur_cs;
@@ -9456,7 +9456,7 @@ ahd_loadseq(struct ahd_softc *ahd)
* Move through the CS table until we find a CS
* that might apply to this instruction.
*/
- for (; cur_cs < num_critical_sections; cur_cs++) {
+ for (; cur_cs < NUM_CRITICAL_SECTIONS; cur_cs++) {
if (critical_sections[cur_cs].end <= i) {
if (begin_set[cs_count] == TRUE
&& end_set[cs_count] == FALSE) {
diff --git a/drivers/scsi/aic7xxx/aic79xx_seq.h_shipped b/drivers/scsi/aic7xxx/aic79xx_seq.h_shipped
index 4b51e232392f..20fb9ca9e271 100644
--- a/drivers/scsi/aic7xxx/aic79xx_seq.h_shipped
+++ b/drivers/scsi/aic7xxx/aic79xx_seq.h_shipped
@@ -1186,5 +1186,4 @@ static const struct cs {
{ 759, 763 }
};
-static const int num_critical_sections = sizeof(critical_sections)
- / sizeof(*critical_sections);
+#define NUM_CRITICAL_SECTIONS 14
diff --git a/drivers/scsi/aic7xxx/aic7xxx_core.c b/drivers/scsi/aic7xxx/aic7xxx_core.c
index 6612ff3b2e83..e97eceacf522 100644
--- a/drivers/scsi/aic7xxx/aic7xxx_core.c
+++ b/drivers/scsi/aic7xxx/aic7xxx_core.c
@@ -6848,9 +6848,9 @@ ahc_dumpseq(struct ahc_softc* ahc)
static int
ahc_loadseq(struct ahc_softc *ahc)
{
- struct cs cs_table[num_critical_sections];
- u_int begin_set[num_critical_sections];
- u_int end_set[num_critical_sections];
+ struct cs cs_table[NUM_CRITICAL_SECTIONS];
+ u_int begin_set[NUM_CRITICAL_SECTIONS];
+ u_int end_set[NUM_CRITICAL_SECTIONS];
const struct patch *cur_patch;
u_int cs_count;
u_int cur_cs;
@@ -6915,7 +6915,7 @@ ahc_loadseq(struct ahc_softc *ahc)
* Move through the CS table until we find a CS
* that might apply to this instruction.
*/
- for (; cur_cs < num_critical_sections; cur_cs++) {
+ for (; cur_cs < NUM_CRITICAL_SECTIONS; cur_cs++) {
if (critical_sections[cur_cs].end <= i) {
if (begin_set[cs_count] == TRUE
&& end_set[cs_count] == FALSE) {
diff --git a/drivers/scsi/aic7xxx/aic7xxx_seq.h_shipped b/drivers/scsi/aic7xxx/aic7xxx_seq.h_shipped
index 07e93fbae706..d814f1d6b820 100644
--- a/drivers/scsi/aic7xxx/aic7xxx_seq.h_shipped
+++ b/drivers/scsi/aic7xxx/aic7xxx_seq.h_shipped
@@ -1304,5 +1304,4 @@ static const struct cs {
{ 875, 877 }
};
-static const int num_critical_sections = sizeof(critical_sections)
- / sizeof(*critical_sections);
+#define NUM_CRITICAL_SECTIONS 7
diff --git a/drivers/scsi/aic7xxx/aicasm/aicasm.c b/drivers/scsi/aic7xxx/aicasm/aicasm.c
index 21ac265280bf..bdffe84221ce 100644
--- a/drivers/scsi/aic7xxx/aicasm/aicasm.c
+++ b/drivers/scsi/aic7xxx/aicasm/aicasm.c
@@ -353,6 +353,7 @@ output_code()
critical_section_t *cs;
symbol_node_t *cur_node;
int instrcount;
+ int num_critical_sections;
instrcount = 0;
fprintf(ofile,
@@ -440,19 +441,20 @@ output_code()
" uint16_t end;\n"
"} critical_sections[] = {\n");
+ num_critical_sections = 0;
for (cs = TAILQ_FIRST(&cs_tailq);
cs != NULL;
cs = TAILQ_NEXT(cs, links)) {
fprintf(ofile, "%s\t{ %d, %d }",
cs == TAILQ_FIRST(&cs_tailq) ? "" : ",\n",
cs->begin_addr, cs->end_addr);
+ num_critical_sections++;
}
fprintf(ofile, "\n};\n\n");
fprintf(ofile,
-"static const int num_critical_sections = sizeof(critical_sections)\n"
-" / sizeof(*critical_sections);\n");
+ "#define NUM_CRITICAL_SECTIONS %d\n", num_critical_sections);
fprintf(stderr, "%s: %d instructions used\n", appname, instrcount);
}
--
2.11.0
On Thu, Mar 8, 2018 at 5:22 AM, Stephen Kitt <[email protected]> wrote:
> In preparation to enabling -Wvla, remove VLAs and replace them with
> fixed-length arrays instead.
>
> The arrays fixed here, using the number of constant sections, aren't
> really VLAs, but they appear so to the compiler. Since we know at
> build-time how many critical sections there are, we might as well use
> a pre-processor-level constant instead.
>
> This was prompted by https://lkml.org/lkml/2018/3/7/621
>
> Signed-off-by: Stephen Kitt <[email protected]>
> ---
> drivers/scsi/aic7xxx/aic79xx_core.c | 8 ++++----
> drivers/scsi/aic7xxx/aic79xx_seq.h_shipped | 3 +--
> drivers/scsi/aic7xxx/aic7xxx_core.c | 8 ++++----
> drivers/scsi/aic7xxx/aic7xxx_seq.h_shipped | 3 +--
> drivers/scsi/aic7xxx/aicasm/aicasm.c | 6 ++++--
> 5 files changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/scsi/aic7xxx/aic79xx_core.c b/drivers/scsi/aic7xxx/aic79xx_core.c
> index b560f396ee99..034f4eebb160 100644
> --- a/drivers/scsi/aic7xxx/aic79xx_core.c
> +++ b/drivers/scsi/aic7xxx/aic79xx_core.c
> @@ -9338,9 +9338,9 @@ ahd_dumpseq(struct ahd_softc* ahd)
> static void
> ahd_loadseq(struct ahd_softc *ahd)
> {
> - struct cs cs_table[num_critical_sections];
> - u_int begin_set[num_critical_sections];
> - u_int end_set[num_critical_sections];
> + struct cs cs_table[NUM_CRITICAL_SECTIONS];
> + u_int begin_set[NUM_CRITICAL_SECTIONS];
> + u_int end_set[NUM_CRITICAL_SECTIONS];
> const struct patch *cur_patch;
> u_int cs_count;
> u_int cur_cs;
> @@ -9456,7 +9456,7 @@ ahd_loadseq(struct ahd_softc *ahd)
> * Move through the CS table until we find a CS
> * that might apply to this instruction.
> */
> - for (; cur_cs < num_critical_sections; cur_cs++) {
> + for (; cur_cs < NUM_CRITICAL_SECTIONS; cur_cs++) {
> if (critical_sections[cur_cs].end <= i) {
> if (begin_set[cs_count] == TRUE
> && end_set[cs_count] == FALSE) {
> diff --git a/drivers/scsi/aic7xxx/aic79xx_seq.h_shipped b/drivers/scsi/aic7xxx/aic79xx_seq.h_shipped
> index 4b51e232392f..20fb9ca9e271 100644
> --- a/drivers/scsi/aic7xxx/aic79xx_seq.h_shipped
> +++ b/drivers/scsi/aic7xxx/aic79xx_seq.h_shipped
> @@ -1186,5 +1186,4 @@ static const struct cs {
> { 759, 763 }
> };
>
> -static const int num_critical_sections = sizeof(critical_sections)
> - / sizeof(*critical_sections);
> +#define NUM_CRITICAL_SECTIONS 14
The compiler doesn't treat "const" as a literal, hence the need to
change this. However, you can still use the sizeof (actually, this is
exactly ARRAY_SIZE()). Perhaps:
#define NUM_CRITICAL_SECTIONS ARRAY_SIZE(critical_sections)
?
Otherwise, looks great!
-Kees
--
Kees Cook
Pixel Security
In preparation to enabling -Wvla, remove VLAs and replace them with
fixed-length arrays instead.
The arrays fixed here, using the number of constant sections, aren't
really VLAs, but they appear so to the compiler. Replace the array
sizes with a pre-processor-level constant instead using ARRAY_SIZE.
This was prompted by https://lkml.org/lkml/2018/3/7/621
Signed-off-by: Stephen Kitt <[email protected]>
---
drivers/scsi/aic7xxx/aic79xx_core.c | 8 ++++----
drivers/scsi/aic7xxx/aic79xx_seq.h_shipped | 3 +--
drivers/scsi/aic7xxx/aic7xxx_core.c | 8 ++++----
drivers/scsi/aic7xxx/aic7xxx_seq.h_shipped | 3 +--
drivers/scsi/aic7xxx/aicasm/aicasm.c | 3 +--
5 files changed, 11 insertions(+), 14 deletions(-)
diff --git a/drivers/scsi/aic7xxx/aic79xx_core.c b/drivers/scsi/aic7xxx/aic79xx_core.c
index b560f396ee99..034f4eebb160 100644
--- a/drivers/scsi/aic7xxx/aic79xx_core.c
+++ b/drivers/scsi/aic7xxx/aic79xx_core.c
@@ -9338,9 +9338,9 @@ ahd_dumpseq(struct ahd_softc* ahd)
static void
ahd_loadseq(struct ahd_softc *ahd)
{
- struct cs cs_table[num_critical_sections];
- u_int begin_set[num_critical_sections];
- u_int end_set[num_critical_sections];
+ struct cs cs_table[NUM_CRITICAL_SECTIONS];
+ u_int begin_set[NUM_CRITICAL_SECTIONS];
+ u_int end_set[NUM_CRITICAL_SECTIONS];
const struct patch *cur_patch;
u_int cs_count;
u_int cur_cs;
@@ -9456,7 +9456,7 @@ ahd_loadseq(struct ahd_softc *ahd)
* Move through the CS table until we find a CS
* that might apply to this instruction.
*/
- for (; cur_cs < num_critical_sections; cur_cs++) {
+ for (; cur_cs < NUM_CRITICAL_SECTIONS; cur_cs++) {
if (critical_sections[cur_cs].end <= i) {
if (begin_set[cs_count] == TRUE
&& end_set[cs_count] == FALSE) {
diff --git a/drivers/scsi/aic7xxx/aic79xx_seq.h_shipped b/drivers/scsi/aic7xxx/aic79xx_seq.h_shipped
index 4b51e232392f..fd64a950ee44 100644
--- a/drivers/scsi/aic7xxx/aic79xx_seq.h_shipped
+++ b/drivers/scsi/aic7xxx/aic79xx_seq.h_shipped
@@ -1186,5 +1186,4 @@ static const struct cs {
{ 759, 763 }
};
-static const int num_critical_sections = sizeof(critical_sections)
- / sizeof(*critical_sections);
+#define NUM_CRITICAL_SECTIONS ARRAY_SIZE(critical_sections)
diff --git a/drivers/scsi/aic7xxx/aic7xxx_core.c b/drivers/scsi/aic7xxx/aic7xxx_core.c
index 6612ff3b2e83..e97eceacf522 100644
--- a/drivers/scsi/aic7xxx/aic7xxx_core.c
+++ b/drivers/scsi/aic7xxx/aic7xxx_core.c
@@ -6848,9 +6848,9 @@ ahc_dumpseq(struct ahc_softc* ahc)
static int
ahc_loadseq(struct ahc_softc *ahc)
{
- struct cs cs_table[num_critical_sections];
- u_int begin_set[num_critical_sections];
- u_int end_set[num_critical_sections];
+ struct cs cs_table[NUM_CRITICAL_SECTIONS];
+ u_int begin_set[NUM_CRITICAL_SECTIONS];
+ u_int end_set[NUM_CRITICAL_SECTIONS];
const struct patch *cur_patch;
u_int cs_count;
u_int cur_cs;
@@ -6915,7 +6915,7 @@ ahc_loadseq(struct ahc_softc *ahc)
* Move through the CS table until we find a CS
* that might apply to this instruction.
*/
- for (; cur_cs < num_critical_sections; cur_cs++) {
+ for (; cur_cs < NUM_CRITICAL_SECTIONS; cur_cs++) {
if (critical_sections[cur_cs].end <= i) {
if (begin_set[cs_count] == TRUE
&& end_set[cs_count] == FALSE) {
diff --git a/drivers/scsi/aic7xxx/aic7xxx_seq.h_shipped b/drivers/scsi/aic7xxx/aic7xxx_seq.h_shipped
index 07e93fbae706..f37362bc8ece 100644
--- a/drivers/scsi/aic7xxx/aic7xxx_seq.h_shipped
+++ b/drivers/scsi/aic7xxx/aic7xxx_seq.h_shipped
@@ -1304,5 +1304,4 @@ static const struct cs {
{ 875, 877 }
};
-static const int num_critical_sections = sizeof(critical_sections)
- / sizeof(*critical_sections);
+#define NUM_CRITICAL_SECTIONS ARRAY_SIZE(critical_sections)
diff --git a/drivers/scsi/aic7xxx/aicasm/aicasm.c b/drivers/scsi/aic7xxx/aicasm/aicasm.c
index 21ac265280bf..5f474e490f3e 100644
--- a/drivers/scsi/aic7xxx/aicasm/aicasm.c
+++ b/drivers/scsi/aic7xxx/aicasm/aicasm.c
@@ -451,8 +451,7 @@ output_code()
fprintf(ofile, "\n};\n\n");
fprintf(ofile,
-"static const int num_critical_sections = sizeof(critical_sections)\n"
-" / sizeof(*critical_sections);\n");
+ "#define NUM_CRITICAL_SECTIONS ARRAY_SIZE(critical_sections)\n");
fprintf(stderr, "%s: %d instructions used\n", appname, instrcount);
}
--
2.11.0
On Thu, Mar 8, 2018 at 12:51 PM, Stephen Kitt <[email protected]> wrote:
> In preparation to enabling -Wvla, remove VLAs and replace them with
> fixed-length arrays instead.
>
> The arrays fixed here, using the number of constant sections, aren't
> really VLAs, but they appear so to the compiler. Replace the array
> sizes with a pre-processor-level constant instead using ARRAY_SIZE.
>
> This was prompted by https://lkml.org/lkml/2018/3/7/621
>
> Signed-off-by: Stephen Kitt <[email protected]>
Thanks!
Reviewed-by: Kees Cook <[email protected]>
-Kees
> ---
> drivers/scsi/aic7xxx/aic79xx_core.c | 8 ++++----
> drivers/scsi/aic7xxx/aic79xx_seq.h_shipped | 3 +--
> drivers/scsi/aic7xxx/aic7xxx_core.c | 8 ++++----
> drivers/scsi/aic7xxx/aic7xxx_seq.h_shipped | 3 +--
> drivers/scsi/aic7xxx/aicasm/aicasm.c | 3 +--
> 5 files changed, 11 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/scsi/aic7xxx/aic79xx_core.c b/drivers/scsi/aic7xxx/aic79xx_core.c
> index b560f396ee99..034f4eebb160 100644
> --- a/drivers/scsi/aic7xxx/aic79xx_core.c
> +++ b/drivers/scsi/aic7xxx/aic79xx_core.c
> @@ -9338,9 +9338,9 @@ ahd_dumpseq(struct ahd_softc* ahd)
> static void
> ahd_loadseq(struct ahd_softc *ahd)
> {
> - struct cs cs_table[num_critical_sections];
> - u_int begin_set[num_critical_sections];
> - u_int end_set[num_critical_sections];
> + struct cs cs_table[NUM_CRITICAL_SECTIONS];
> + u_int begin_set[NUM_CRITICAL_SECTIONS];
> + u_int end_set[NUM_CRITICAL_SECTIONS];
> const struct patch *cur_patch;
> u_int cs_count;
> u_int cur_cs;
> @@ -9456,7 +9456,7 @@ ahd_loadseq(struct ahd_softc *ahd)
> * Move through the CS table until we find a CS
> * that might apply to this instruction.
> */
> - for (; cur_cs < num_critical_sections; cur_cs++) {
> + for (; cur_cs < NUM_CRITICAL_SECTIONS; cur_cs++) {
> if (critical_sections[cur_cs].end <= i) {
> if (begin_set[cs_count] == TRUE
> && end_set[cs_count] == FALSE) {
> diff --git a/drivers/scsi/aic7xxx/aic79xx_seq.h_shipped b/drivers/scsi/aic7xxx/aic79xx_seq.h_shipped
> index 4b51e232392f..fd64a950ee44 100644
> --- a/drivers/scsi/aic7xxx/aic79xx_seq.h_shipped
> +++ b/drivers/scsi/aic7xxx/aic79xx_seq.h_shipped
> @@ -1186,5 +1186,4 @@ static const struct cs {
> { 759, 763 }
> };
>
> -static const int num_critical_sections = sizeof(critical_sections)
> - / sizeof(*critical_sections);
> +#define NUM_CRITICAL_SECTIONS ARRAY_SIZE(critical_sections)
> diff --git a/drivers/scsi/aic7xxx/aic7xxx_core.c b/drivers/scsi/aic7xxx/aic7xxx_core.c
> index 6612ff3b2e83..e97eceacf522 100644
> --- a/drivers/scsi/aic7xxx/aic7xxx_core.c
> +++ b/drivers/scsi/aic7xxx/aic7xxx_core.c
> @@ -6848,9 +6848,9 @@ ahc_dumpseq(struct ahc_softc* ahc)
> static int
> ahc_loadseq(struct ahc_softc *ahc)
> {
> - struct cs cs_table[num_critical_sections];
> - u_int begin_set[num_critical_sections];
> - u_int end_set[num_critical_sections];
> + struct cs cs_table[NUM_CRITICAL_SECTIONS];
> + u_int begin_set[NUM_CRITICAL_SECTIONS];
> + u_int end_set[NUM_CRITICAL_SECTIONS];
> const struct patch *cur_patch;
> u_int cs_count;
> u_int cur_cs;
> @@ -6915,7 +6915,7 @@ ahc_loadseq(struct ahc_softc *ahc)
> * Move through the CS table until we find a CS
> * that might apply to this instruction.
> */
> - for (; cur_cs < num_critical_sections; cur_cs++) {
> + for (; cur_cs < NUM_CRITICAL_SECTIONS; cur_cs++) {
> if (critical_sections[cur_cs].end <= i) {
> if (begin_set[cs_count] == TRUE
> && end_set[cs_count] == FALSE) {
> diff --git a/drivers/scsi/aic7xxx/aic7xxx_seq.h_shipped b/drivers/scsi/aic7xxx/aic7xxx_seq.h_shipped
> index 07e93fbae706..f37362bc8ece 100644
> --- a/drivers/scsi/aic7xxx/aic7xxx_seq.h_shipped
> +++ b/drivers/scsi/aic7xxx/aic7xxx_seq.h_shipped
> @@ -1304,5 +1304,4 @@ static const struct cs {
> { 875, 877 }
> };
>
> -static const int num_critical_sections = sizeof(critical_sections)
> - / sizeof(*critical_sections);
> +#define NUM_CRITICAL_SECTIONS ARRAY_SIZE(critical_sections)
> diff --git a/drivers/scsi/aic7xxx/aicasm/aicasm.c b/drivers/scsi/aic7xxx/aicasm/aicasm.c
> index 21ac265280bf..5f474e490f3e 100644
> --- a/drivers/scsi/aic7xxx/aicasm/aicasm.c
> +++ b/drivers/scsi/aic7xxx/aicasm/aicasm.c
> @@ -451,8 +451,7 @@ output_code()
> fprintf(ofile, "\n};\n\n");
>
> fprintf(ofile,
> -"static const int num_critical_sections = sizeof(critical_sections)\n"
> -" / sizeof(*critical_sections);\n");
> + "#define NUM_CRITICAL_SECTIONS ARRAY_SIZE(critical_sections)\n");
>
> fprintf(stderr, "%s: %d instructions used\n", appname, instrcount);
> }
> --
> 2.11.0
>
--
Kees Cook
Pixel Security
On Thu, 8 Mar 2018 11:52:25 -0800, Kees Cook <[email protected]> wrote:
> On Thu, Mar 8, 2018 at 5:22 AM, Stephen Kitt <[email protected]> wrote:
> > -static const int num_critical_sections = sizeof(critical_sections)
> > - / sizeof(*critical_sections);
> > +#define NUM_CRITICAL_SECTIONS 14
>
> The compiler doesn't treat "const" as a literal, hence the need to
> change this. However, you can still use the sizeof (actually, this is
> exactly ARRAY_SIZE()). Perhaps:
>
> #define NUM_CRITICAL_SECTIONS ARRAY_SIZE(critical_sections)
>
> ?
>
> Otherwise, looks great!
Thanks, v2 incoming...
Regards,
Stephen
Stephen,
> In preparation to enabling -Wvla, remove VLAs and replace them with
> fixed-length arrays instead.
>
> The arrays fixed here, using the number of constant sections, aren't
> really VLAs, but they appear so to the compiler. Replace the array
> sizes with a pre-processor-level constant instead using ARRAY_SIZE.
Applied to 4.17/scsi-queue.
--
Martin K. Petersen Oracle Linux Engineering