[PATCH 13/33] efi/gop: Remove unreachable code from setup_pixel_info

Ard Biesheuvel
2020-04-24T13:06:44Z

From: Arvind Sankar <nivedita@alum.mit.edu>

pixel_format must be one of
PIXEL_RGB_RESERVED_8BIT_PER_COLOR
PIXEL_BGR_RESERVED_8BIT_PER_COLOR
PIXEL_BIT_MASK
since we skip PIXEL_BLT_ONLY when finding a gop.

Remove the redundant code and add another check in find_gop to skip any
pixel formats that we don't know about, in case a later version of the
UEFI spec adds one.

Reformat the code a little.

Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Link: https://lore.kernel.org/r/20200320020028.1936003-10-nivedita@alum.mit.edu
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
drivers/firmware/efi/libstub/gop.c | 66 ++++++++++++------------------
1 file changed, 26 insertions(+), 40 deletions(-)

diff --git a/drivers/firmware/efi/libstub/gop.c b/drivers/firmware/efi/libstub/gop.c
index 8bf424f35759..2d91699e3061 100644
--- a/drivers/firmware/efi/libstub/gop.c
+++ b/drivers/firmware/efi/libstub/gop.c
@@ -29,49 +29,34 @@ static void
setup_pixel_info(struct screen_info *si, u32 pixels_per_scan_line,
efi_pixel_bitmask_t pixel_info, int pixel_format)
{
- if (pixel_format == PIXEL_RGB_RESERVED_8BIT_PER_COLOR) {
- si->lfb_depth = 32;
- si->lfb_linelength = pixels_per_scan_line * 4;
- si->red_size = 8;
- si->red_pos = 0;
- si->green_size = 8;
- si->green_pos = 8;
- si->blue_size = 8;
- si->blue_pos = 16;
- si->rsvd_size = 8;
- si->rsvd_pos = 24;
- } else if (pixel_format == PIXEL_BGR_RESERVED_8BIT_PER_COLOR) {
- si->lfb_depth = 32;
- si->lfb_linelength = pixels_per_scan_line * 4;
- si->red_size = 8;
- si->red_pos = 16;
- si->green_size = 8;
- si->green_pos = 8;
- si->blue_size = 8;
- si->blue_pos = 0;
- si->rsvd_size = 8;
- si->rsvd_pos = 24;
- } else if (pixel_format == PIXEL_BIT_MASK) {
- find_bits(pixel_info.red_mask, &si->red_pos, &si->red_size);
- find_bits(pixel_info.green_mask, &si->green_pos,
- &si->green_size);
- find_bits(pixel_info.blue_mask, &si->blue_pos, &si->blue_size);
- find_bits(pixel_info.reserved_mask, &si->rsvd_pos,
- &si->rsvd_size);
+ if (pixel_format == PIXEL_BIT_MASK) {
+ find_bits(pixel_info.red_mask,
+ &si->red_pos, &si->red_size);
+ find_bits(pixel_info.green_mask,
+ &si->green_pos, &si->green_size);
+ find_bits(pixel_info.blue_mask,
+ &si->blue_pos, &si->blue_size);
+ find_bits(pixel_info.reserved_mask,
+ &si->rsvd_pos, &si->rsvd_size);
si->lfb_depth = si->red_size + si->green_size +
si->blue_size + si->rsvd_size;
si->lfb_linelength = (pixels_per_scan_line * si->lfb_depth) / 8;
} else {
- si->lfb_depth = 4;
- si->lfb_linelength = si->lfb_width / 2;
- si->red_size = 0;
- si->red_pos = 0;
- si->green_size = 0;
- si->green_pos = 0;
- si->blue_size = 0;
- si->blue_pos = 0;
- si->rsvd_size = 0;
- si->rsvd_pos = 0;
+ if (pixel_format == PIXEL_RGB_RESERVED_8BIT_PER_COLOR) {
+ si->red_pos = 0;
+ si->blue_pos = 16;
+ } else /* PIXEL_BGR_RESERVED_8BIT_PER_COLOR */ {
+ si->blue_pos = 0;
+ si->red_pos = 16;
+ }
+
+ si->green_pos = 8;
+ si->rsvd_pos = 24;
+ si->red_size = si->green_size =
+ si->blue_size = si->rsvd_size = 8;
+
+ si->lfb_depth = 32;
+ si->lfb_linelength = pixels_per_scan_line * 4;
}
}

@@ -100,7 +85,8 @@ find_gop(efi_guid_t *proto, unsigned long size, void **handles)

mode = efi_table_attr(gop, mode);
info = efi_table_attr(mode, info);
- if (info->pixel_format == PIXEL_BLT_ONLY)
+ if (info->pixel_format == PIXEL_BLT_ONLY ||
+ info->pixel_format >= PIXEL_FORMAT_MAX)
continue;

/*
--
2.17.1