Re: [PATCH v2] media: venus: Constify struct dec_bufsize_ops and enc_bufsize_ops

From: Bryan O'Donoghue
Date: Mon Jun 03 2024 - 19:02:21 EST


On 02/06/2024 15:27, Christophe JAILLET wrote:
"struct dec_bufsize_ops and "struct enc_bufsize_ops" are not modified in
this driver.

Constifying these structures moves some data to a read-only section, so
increase overall security.

On a x86_64, with allmodconfig:
Before:
text data bss dec hex filename
12494 822 0 13316 3404 drivers/media/platform/qcom/venus/hfi_plat_bufs_v6.o

After:
text data bss dec hex filename
12766 566 0 13332 3414 drivers/media/platform/qcom/venus/hfi_plat_bufs_v6.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
Changes in v2:
- Add missing prefix in the subject

v1: https://lore.kernel.org/all/9bc4b28a55c42fa4a125c3e03d4c8b0f208550b4.1717313173.git.christophe.jaillet@xxxxxxxxxx/

While looking at lore to find the reference above, I found that this
patch had already been sent by Rikard Falkeborn <rikard.falkeborn@xxxxxxxxx>
See: https://lore.kernel.org/all/20211212123534.4473-1-rikard.falkeborn@xxxxxxxxx/

So, if applied, credits should be for him.
So feel free to add a Co-Developed-by:, Reported-by:, Suggested-by: or
whatever makes sense, including removing my Signed-off-by: to put his if
it sounds better to do it this way.

.../platform/qcom/venus/hfi_plat_bufs_v6.c | 20 +++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/media/platform/qcom/venus/hfi_plat_bufs_v6.c b/drivers/media/platform/qcom/venus/hfi_plat_bufs_v6.c
index f5a655973c08..6289166786ec 100644
--- a/drivers/media/platform/qcom/venus/hfi_plat_bufs_v6.c
+++ b/drivers/media/platform/qcom/venus/hfi_plat_bufs_v6.c
@@ -1063,51 +1063,51 @@ struct enc_bufsize_ops {
u32 (*persist)(void);
};
-static struct dec_bufsize_ops dec_h264_ops = {
+static const struct dec_bufsize_ops dec_h264_ops = {
.scratch = h264d_scratch_size,
.scratch1 = h264d_scratch1_size,
.persist1 = h264d_persist1_size,
};
-static struct dec_bufsize_ops dec_h265_ops = {
+static const struct dec_bufsize_ops dec_h265_ops = {
.scratch = h265d_scratch_size,
.scratch1 = h265d_scratch1_size,
.persist1 = h265d_persist1_size,
};
-static struct dec_bufsize_ops dec_vp8_ops = {
+static const struct dec_bufsize_ops dec_vp8_ops = {
.scratch = vpxd_scratch_size,
.scratch1 = vp8d_scratch1_size,
.persist1 = vp8d_persist1_size,
};
-static struct dec_bufsize_ops dec_vp9_ops = {
+static const struct dec_bufsize_ops dec_vp9_ops = {
.scratch = vpxd_scratch_size,
.scratch1 = vp9d_scratch1_size,
.persist1 = vp9d_persist1_size,
};
-static struct dec_bufsize_ops dec_mpeg2_ops = {
+static const struct dec_bufsize_ops dec_mpeg2_ops = {
.scratch = mpeg2d_scratch_size,
.scratch1 = mpeg2d_scratch1_size,
.persist1 = mpeg2d_persist1_size,
};
-static struct enc_bufsize_ops enc_h264_ops = {
+static const struct enc_bufsize_ops enc_h264_ops = {
.scratch = h264e_scratch_size,
.scratch1 = h264e_scratch1_size,
.scratch2 = enc_scratch2_size,
.persist = enc_persist_size,
};
-static struct enc_bufsize_ops enc_h265_ops = {
+static const struct enc_bufsize_ops enc_h265_ops = {
.scratch = h265e_scratch_size,
.scratch1 = h265e_scratch1_size,
.scratch2 = enc_scratch2_size,
.persist = enc_persist_size,
};
-static struct enc_bufsize_ops enc_vp8_ops = {
+static const struct enc_bufsize_ops enc_vp8_ops = {
.scratch = vp8e_scratch_size,
.scratch1 = vp8e_scratch1_size,
.scratch2 = enc_scratch2_size,
@@ -1186,7 +1186,7 @@ static int bufreq_dec(struct hfi_plat_buffers_params *params, u32 buftype,
u32 codec = params->codec;
u32 width = params->width, height = params->height, out_min_count;
u32 out_width = params->out_width, out_height = params->out_height;
- struct dec_bufsize_ops *dec_ops;
+ const struct dec_bufsize_ops *dec_ops;
bool is_secondary_output = params->dec.is_secondary_output;
bool is_interlaced = params->dec.is_interlaced;
u32 max_mbs_per_frame = params->dec.max_mbs_per_frame;
@@ -1260,7 +1260,7 @@ static int bufreq_enc(struct hfi_plat_buffers_params *params, u32 buftype,
struct hfi_buffer_requirements *bufreq)
{
enum hfi_version version = params->version;
- struct enc_bufsize_ops *enc_ops;
+ const struct enc_bufsize_ops *enc_ops;
u32 width = params->width;
u32 height = params->height;
bool is_tenbit = params->enc.is_tenbit;

Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>