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cli: Correct several bugs in cli_getch()

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This function does not behave as expected when unknown escape sequences
are sent to it:

- it fails to store (and thus echo) the last character of the invalid
  sequence
- it fails to set esc_len to 0 when it finishes emitting the invalid
  sequence, meaning that the following character will appear to be part
  of a new escape sequence
- it processes the first character of the rejected sequence as a valid
  character, just starting the sequence all over again

The last two bugs conspire to produce an "impossible condition #876"
message which is the main symptom of this behaviour.

Fix these bugs and add a test to verify the behaviour.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
This commit is contained in:
Simon Glass 2023-03-28 08:34:13 +13:00 committed by Tom Rini
parent 41a88ad529
commit 17b45e684a
3 changed files with 52 additions and 2 deletions
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5
common/cli_getch.c
View file

@ -129,7 +129,7 @@ static int cli_ch_esc(struct cli_ch_state *cch, int ichar,
*actp = act;
return act == ESC_CONVERTED ? ichar : 0;
return ichar;
}
int cli_ch_process(struct cli_ch_state *cch, int ichar)
@ -145,6 +145,7 @@ int cli_ch_process(struct cli_ch_state *cch, int ichar)
return cch->esc_save[cch->emit_upto++];
cch->emit_upto = 0;
cch->emitting = false;
cch->esc_len = 0;
}
return 0;
} else if (ichar == -ETIMEDOUT) {
@ -185,7 +186,7 @@ int cli_ch_process(struct cli_ch_state *cch, int ichar)
cch->esc_save[cch->esc_len++] = ichar;
ichar = cch->esc_save[cch->emit_upto++];
cch->emitting = true;
break;
return ichar;
case ESC_CONVERTED:
/* valid escape sequence, return the resulting char */
cch->esc_len = 0;

1
test/common/Makefile
View file

@ -3,3 +3,4 @@ obj-y += cmd_ut_common.o
obj-$(CONFIG_AUTOBOOT) += test_autoboot.o
obj-$(CONFIG_CYCLIC) += cyclic.o
obj-$(CONFIG_EVENT) += event.o
obj-y += cread.o

48
test/common/cread.c Normal file
View file

@ -0,0 +1,48 @@
// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2023 Google LLC
*/
#include <common.h>
#include <cli.h>
#include <test/common.h>
#include <test/test.h>
#include <test/ut.h>
static int cli_ch_test(struct unit_test_state *uts)
{
struct cli_ch_state s_cch, *cch = &s_cch;
cli_ch_init(cch);
/* should be nothing to return at first */
ut_asserteq(0, cli_ch_process(cch, 0));
/* check normal entry */
ut_asserteq('a', cli_ch_process(cch, 'a'));
ut_asserteq('b', cli_ch_process(cch, 'b'));
ut_asserteq('c', cli_ch_process(cch, 'c'));
ut_asserteq(0, cli_ch_process(cch, 0));
/* send an invalid escape sequence */
ut_asserteq(0, cli_ch_process(cch, '\e'));
ut_asserteq(0, cli_ch_process(cch, '['));
/*
* with the next char it sees that the sequence is invalid, so starts
* emitting it
*/
ut_asserteq('\e', cli_ch_process(cch, 'X'));
/* now we set 0 bytes to empty the buffer */
ut_asserteq('[', cli_ch_process(cch, 0));
ut_asserteq('X', cli_ch_process(cch, 0));
ut_asserteq(0, cli_ch_process(cch, 0));
/* things are normal again */
ut_asserteq('a', cli_ch_process(cch, 'a'));
ut_asserteq(0, cli_ch_process(cch, 0));
return 0;
}
COMMON_TEST(cli_ch_test, 0);