Date: Fri, 30 Dec 2016 18:21:53 +0000 (UTC) From: Toomas Soome <tsoome@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r310845 - head/sys/boot/i386/common Message-ID: <201612301821.uBUILrDc024348@repo.freebsd.org>
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Author: tsoome Date: Fri Dec 30 18:21:52 2016 New Revision: 310845 URL: https://svnweb.freebsd.org/changeset/base/310845 Log: boot2 will deadlock if extended keys are used on text input The boot2 family of bootblocks (zfsboot/gptzfsboot) are using separate implementation if keyboard reading code, which has deadlock case when extended key (arrows etc) are pressed. The problem is about avoiding the noise from some systems, generating false key events with scan code 1 and ascii code 00, so the code does attempt to filter such cases out. Unfortunately the extended keys also set ascii 0, and therefore the pressed key event is ignored and the keypress is never read, resulting in infinite loop. This update is moving the check to keyhit() function and is allowing the rest of the code to process the extended keys. Reviewed by: bapt, allanjude Approved by: allanjude (mentor) MFC after: 1 month Differential Revision: https://reviews.freebsd.org/D8608 Modified: head/sys/boot/i386/common/cons.c Modified: head/sys/boot/i386/common/cons.c ============================================================================== --- head/sys/boot/i386/common/cons.c Fri Dec 30 18:17:44 2016 (r310844) +++ head/sys/boot/i386/common/cons.c Fri Dec 30 18:21:52 2016 (r310845) @@ -65,18 +65,17 @@ int getc(int fn) { - /* - * The extra comparison against zero is an attempt to work around - * what appears to be a bug in QEMU and Bochs. Both emulators - * sometimes report a key-press with scancode one and ascii zero - * when no such key is pressed in reality. As far as I can tell, - * this only happens shortly after a reboot. - */ v86.ctl = V86_FLAGS; v86.addr = 0x16; v86.eax = fn << 8; v86int(); - return fn == 0 ? v86.eax & 0xff : (!V86_ZR(v86.efl) && (v86.eax & 0xff)); + + if (fn == 0) + return (v86.eax); + + if (V86_ZR(v86.efl)) + return (0); + return (v86.eax); } int @@ -106,14 +105,22 @@ getchar(void) int keyhit(unsigned int secs) { - uint32_t t0, t1; + uint32_t t0, t1, c; if (OPT_CHECK(RBX_NOINTR)) return (0); secs *= SECOND; t0 = 0; for (;;) { - if (xgetc(1)) + /* + * The extra comparison is an attempt to work around + * what appears to be a bug in QEMU and Bochs. Both emulators + * sometimes report a key-press with scancode one and ascii zero + * when no such key is pressed in reality. As far as I can tell, + * this only happens shortly after a reboot. + */ + c = xgetc(1); + if (c != 0 && c != 0x0100) return (1); if (secs > 0) { t1 = *(uint32_t *)PTOV(0x46c); @@ -134,9 +141,19 @@ getstr(char *cmdstr, size_t cmdstrsize) s = cmdstr; for (;;) { - switch (c = xgetc(0)) { - case 0: + c = xgetc(0); + + /* Translate some extended codes. */ + switch (c) { + case 0x5300: /* delete */ + c = '\177'; break; + default: + c &= 0xff; + break; + } + + switch (c) { case '\177': case '\b': if (s > cmdstr) { @@ -149,9 +166,11 @@ getstr(char *cmdstr, size_t cmdstrsize) *s = 0; return; default: - if (s - cmdstr < cmdstrsize - 1) - *s++ = c; - putchar(c); + if (c >= 0x20 && c <= 0x7e) { + if (s - cmdstr < cmdstrsize - 1) + *s++ = c; + putchar(c); + } break; } }
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