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| author | Nicolas Pitre <nicolas.pitre@linaro.org> | 2018-07-17 21:02:41 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-21 09:18:27 +0200 |
| commit | 0224080fc878f8b1f3317fa0ba3728df6bb9d53e (patch) | |
| tree | c9f387516d635a91fbfca8873958e6e4179d6ce1 | |
| parent | 9bfdc2611d417be453c3deb7a7ef2ffc718febfa (diff) | |
| download | linux-stable-0224080fc878f8b1f3317fa0ba3728df6bb9d53e.tar.gz linux-stable-0224080fc878f8b1f3317fa0ba3728df6bb9d53e.tar.bz2 linux-stable-0224080fc878f8b1f3317fa0ba3728df6bb9d53e.zip | |
vt: coherence validation code for the unicode screen buffer
Make sure the unicode screen buffer matches the video screen content.
This is provided for debugging convenience and disabled by default.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/vt/vt.c | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/drivers/tty/vt/vt.c b/drivers/tty/vt/vt.c index 7adcb6dcc50c..4b3c371f0f84 100644 --- a/drivers/tty/vt/vt.c +++ b/drivers/tty/vt/vt.c @@ -328,6 +328,8 @@ void schedule_console_callback(void) #define get_vc_uniscr(vc) vc->vc_uni_screen #endif +#define VC_UNI_SCREEN_DEBUG 0 + typedef uint32_t char32_t; /* @@ -569,6 +571,42 @@ void vc_uniscr_copy_line(struct vc_data *vc, void *dest, int viewed, } } +/* this is for validation and debugging only */ +static void vc_uniscr_debug_check(struct vc_data *vc) +{ + struct uni_screen *uniscr = get_vc_uniscr(vc); + unsigned short *p; + int x, y, mask; + + if (!VC_UNI_SCREEN_DEBUG || !uniscr) + return; + + WARN_CONSOLE_UNLOCKED(); + + /* + * Make sure our unicode screen translates into the same glyphs + * as the actual screen. This is brutal indeed. + */ + p = (unsigned short *)vc->vc_origin; + mask = vc->vc_hi_font_mask | 0xff; + for (y = 0; y < vc->vc_rows; y++) { + char32_t *line = uniscr->lines[y]; + for (x = 0; x < vc->vc_cols; x++) { + u16 glyph = scr_readw(p++) & mask; + char32_t uc = line[x]; + int tc = conv_uni_to_pc(vc, uc); + if (tc == -4) + tc = conv_uni_to_pc(vc, 0xfffd); + if (tc == -4) + tc = conv_uni_to_pc(vc, '?'); + if (tc != glyph) + pr_err_ratelimited( + "%s: mismatch at %d,%d: glyph=%#x tc=%#x\n", + __func__, x, y, glyph, tc); + } + } +} + static void con_scroll(struct vc_data *vc, unsigned int t, unsigned int b, enum con_scroll dir, unsigned int nr) @@ -2717,6 +2755,7 @@ rescan_last_byte: do_con_trol(tty, vc, orig); } con_flush(vc, draw_from, draw_to, &draw_x); + vc_uniscr_debug_check(vc); console_conditional_schedule(); console_unlock(); notify_update(vc); |