126256 2006-04-25 23:41:44 +0000 (fnop) vex x86->IR: unhandled instruction bytes: 0xD9 0xD0 0x31 0xC0 2026-01-17 16:59:09 +0000 1 1 6 Developer tools valgrind vex 3.2 SVN Compiled Sources Linux RESOLVED FIXED NOR crash --- 256630 1 thomas-dloop jseward mark mark vince 0 oldest_to_newest 433950 0 thomas-dloop 2006-04-25 23:41:44 +0000 3: e8 fc ff ff ff call 4 <_Dmain+0x4> 8: d9 d0 fnop a: 5d pop ebp (http://dstress.kuehne.cn/run/a/asm_fnop_01.d) 2485305 1 mark 2026-01-15 18:40:23 +0000 I have a similar case that I reported on the users list together with a proposed fix (see https://sourceforge.net/p/valgrind/mailman/message/59283753/). The attached patch has a test for reproducing the issue and a fix for x86 and amd64 (that should also address bug 253446). 2485306 2 188561 mark 2026-01-15 18:41:36 +0000 Created attachment 188561 Add support for fnop instruction on x86 and amd64 2485462 3 mark 2026-01-16 12:08:00 +0000 *** Bug 253446 has been marked as a duplicate of this bug. *** 2485463 4 mark 2026-01-16 12:11:26 +0000 (In reply to Mark from comment #2) > Created attachment 188561 [details] > Add support for fnop instruction on x86 and amd64 Thanks, this looks good. Apologies this was never "implemented". At first I was afraid this needed some subtle floating point exception signaling. Which technically it does, but that is currently a known limitation according to the TODO at the top of the file - x87 FP Limitations: * no FP exceptions, except for handling stack over/underflow So this seems good to go, thanks for the testcases. 2485838 5 mark 2026-01-17 16:59:09 +0000 commit a615e4daebe2b7289beb66019493285cfc58c2bc Author: Mark <mark@zbuffer.de> Date: Sat Jan 17 17:22:59 2026 +0100 Add support for fnop instruction on x86 and amd64 This implements FNOP in guest_amd64_toIR.c and guest_x86_toIR.c by simply skipping the instruction. Which is OK for now since one of the x87 FP Limitations is no FP exceptions, except for handling stack over/underflow. Add fnop to none/tests/{amd64,x86}/insn_fpu.{def,stdout.exp}. Also update old 3_1_BUGSTATUS.txt to correct bug number. https://bugs.kde.org/show_bug.cgi?id=126256 188561 2026-01-15 18:41:36 +0000 2026-01-15 18:41:36 +0000 Add support for fnop instruction on x86 and amd64 full.patch text/plain 3082 mark ZGlmZiAtLWdpdCBhL1ZFWC9wcml2L2d1ZXN0X2FtZDY0X3RvSVIuYyBiL1ZFWC9wcml2L2d1ZXN0 X2FtZDY0X3RvSVIuYwppbmRleCAzNGViY2JkZjkuLjAzMTk1NzhmMiAxMDA2NDQKLS0tIGEvVkVY L3ByaXYvZ3Vlc3RfYW1kNjRfdG9JUi5jCisrKyBiL1ZFWC9wcml2L2d1ZXN0X2FtZDY0X3RvSVIu YwpAQCAtNTk2Nyw2ICs1OTY3LDEwIEBAIFVMb25nIGRpc19GUFUgKCAvKk9VVCovQm9vbCogZGVj b2RlX29rLAogICAgICAgICAgICAgICAgcHV0X1NUX1VOQ0hFQ0tFRChyX3NyYywgbWtleHByKHQx KSk7CiAgICAgICAgICAgICAgICBicmVhazsKIAorICAgICAgICAgICAgY2FzZSAweEQwOiAvKiBG Tk9QICovCisgICAgICAgICAgICAgICBESVAoImZub3BcbiIpOworICAgICAgICAgICAgICAgYnJl YWs7CisKICAgICAgICAgICAgIGNhc2UgMHhFMDogLyogRkNIUyAqLwogICAgICAgICAgICAgICAg RElQKCJmY2hzXG4iKTsKICAgICAgICAgICAgICAgIHB1dF9TVF9VTkNIRUNLRUQoMCwgdW5vcChJ b3BfTmVnRjY0LCBnZXRfU1QoMCkpKTsKZGlmZiAtLWdpdCBhL1ZFWC9wcml2L2d1ZXN0X3g4Nl90 b0lSLmMgYi9WRVgvcHJpdi9ndWVzdF94ODZfdG9JUi5jCmluZGV4IGJkNGNjZDU0Yi4uNzEwOTA1 YWQxIDEwMDY0NAotLS0gYS9WRVgvcHJpdi9ndWVzdF94ODZfdG9JUi5jCisrKyBiL1ZFWC9wcml2 L2d1ZXN0X3g4Nl90b0lSLmMKQEAgLTQyMDQsNiArNDIwNCwxMCBAQCBVSW50IGRpc19GUFUgKCBC b29sKiBkZWNvZGVfb2ssIFVDaGFyIHNvcmIsIEludCBkZWx0YSApCiAgICAgICAgICAgICAgICBw dXRfU1RfVU5DSEVDS0VEKHJfc3JjLCBta2V4cHIodDEpKTsKICAgICAgICAgICAgICAgIGJyZWFr OwogCisgICAgICAgICAgICBjYXNlIDB4RDA6IC8qIEZOT1AgKi8KKyAgICAgICAgICAgICAgIERJ UCgiZm5vcFxuIik7CisgICAgICAgICAgICAgICBicmVhazsKKwogICAgICAgICAgICAgY2FzZSAw eEUwOiAvKiBGQ0hTICovCiAgICAgICAgICAgICAgICBESVAoImZjaHNcbiIpOwogICAgICAgICAg ICAgICAgcHV0X1NUX1VOQ0hFQ0tFRCgwLCB1bm9wKElvcF9OZWdGNjQsIGdldF9TVCgwKSkpOwpk aWZmIC0tZ2l0IGEvZG9jcy9pbnRlcm5hbHMvM18xX0JVR1NUQVRVUy50eHQgYi9kb2NzL2ludGVy bmFscy8zXzFfQlVHU1RBVFVTLnR4dAppbmRleCA2YWRkMGNjYWMuLjQxMzRjM2NiOSAxMDA2NDQK LS0tIGEvZG9jcy9pbnRlcm5hbHMvM18xX0JVR1NUQVRVUy50eHQKKysrIGIvZG9jcy9pbnRlcm5h bHMvM18xX0JVR1NUQVRVUy50eHQKQEAgLTU0LDcgKzU0LDcgQEAgdjU4NzcgICAgIGZpeGVkICAg MTI2MjE3ICBpbmNyZWFzZSAjIHRocmVhZHMKIHY1ODgwICAgICBmaXhlZCAgIG4taS1ieiAgdmVj dG9yaXNlIGNvcHlfYWRkcmVzc19yYW5nZV9zdGF0ZQogICAgICAgICAgICAgICAgICAgbi1pLWJ6 ICBtcGljYyAtZnBpYyBidWcgKEdvZWRla2VuIFJpY2hhcmQsIGluYm94KQogdngxNjExICAgIGZp eGVkICAgMTI2MjQzICB2ZXggeDg2LT5JUjogcG9wdyBtZW0KLSAgICAgICAgICBsb3cgICAgIDEy NTI2NSAgdmV4IHg4Ni0+SVI6IDB4RDkgMHhEMCAoZm5vcCkKKyAgICAgICAgICBsb3cgICAgIDEy NjI1NiAgdmV4IHg4Ni0+SVI6IDB4RDkgMHhEMCAoZm5vcCkKICAgICAgICAgICBsb3cgICAgIDEy NjI1NyAgdmV4IHg4Ni0+SVI6IDB4RjIgMHgwRiAweEYwIDB4NDAgKGxkZHF1KSAoc3NlMykKICAg ICAgICAgICBsb3cgICAgIDEyNjI1OCAgdmV4IHg4Ni0+SVI6IDB4REYgMHg0RCAoZmlzdHRwKSAo c3NlMykKICAgICAgICAgICAgICAgICAgIDEyNjM4NCAgcmRwbWMKZGlmZiAtLWdpdCBhL25vbmUv dGVzdHMvYW1kNjQvaW5zbl9mcHUuZGVmIGIvbm9uZS90ZXN0cy9hbWQ2NC9pbnNuX2ZwdS5kZWYK aW5kZXggNTI1ZmQxYjFiLi4yMTkyNDc0NzggMTAwNjQ0Ci0tLSBhL25vbmUvdGVzdHMvYW1kNjQv aW5zbl9mcHUuZGVmCisrKyBiL25vbmUvdGVzdHMvYW1kNjQvaW5zbl9mcHUuZGVmCkBAIC0xLDMg KzEsNCBAQAorZm5vcAogZmFicyBzdDAucHNbMTIzNC41Njc4XSA6ID0+IHN0MC5wc1sxMjM0LjU2 NzhdCiBmYWJzIHN0MC5wc1stMTIzNC41Njc4XSA6ID0+IHN0MC5wc1sxMjM0LjU2NzhdCiBmYWJz IHN0MC5wZFsxMjM0NTY3OC44NzY1NDMyMV0gOiA9PiBzdDAucGRbMTIzNDU2NzguODc2NTQzMjFd CmRpZmYgLS1naXQgYS9ub25lL3Rlc3RzL2FtZDY0L2luc25fZnB1LnN0ZG91dC5leHAgYi9ub25l L3Rlc3RzL2FtZDY0L2luc25fZnB1LnN0ZG91dC5leHAKaW5kZXggNjcxMjhjMTNiLi5mNWY0YTE2 MWYgMTAwNjQ0Ci0tLSBhL25vbmUvdGVzdHMvYW1kNjQvaW5zbl9mcHUuc3Rkb3V0LmV4cAorKysg Yi9ub25lL3Rlc3RzL2FtZDY0L2luc25fZnB1LnN0ZG91dC5leHAKQEAgLTEsMyArMSw0IEBACitm bm9wXzEgLi4uIG9rCiBmYWJzXzEgLi4uIG9rCiBmYWJzXzIgLi4uIG9rCiBmYWJzXzMgLi4uIG9r CmRpZmYgLS1naXQgYS9ub25lL3Rlc3RzL3g4Ni9pbnNuX2ZwdS5kZWYgYi9ub25lL3Rlc3RzL3g4 Ni9pbnNuX2ZwdS5kZWYKaW5kZXggNTkwZjU4NDRjLi5mNWE4ZDYxYzQgMTAwNjQ0Ci0tLSBhL25v bmUvdGVzdHMveDg2L2luc25fZnB1LmRlZgorKysgYi9ub25lL3Rlc3RzL3g4Ni9pbnNuX2ZwdS5k ZWYKQEAgLTEsMyArMSw0IEBACitmbm9wCiBmYWJzIHN0MC5wc1sxMjM0LjU2NzhdIDogPT4gc3Qw LnBzWzEyMzQuNTY3OF0KIGZhYnMgc3QwLnBzWy0xMjM0LjU2NzhdIDogPT4gc3QwLnBzWzEyMzQu NTY3OF0KIGZhYnMgc3QwLnBkWzEyMzQ1Njc4Ljg3NjU0MzIxXSA6ID0+IHN0MC5wZFsxMjM0NTY3 OC44NzY1NDMyMV0KZGlmZiAtLWdpdCBhL25vbmUvdGVzdHMveDg2L2luc25fZnB1LnN0ZG91dC5l eHAgYi9ub25lL3Rlc3RzL3g4Ni9pbnNuX2ZwdS5zdGRvdXQuZXhwCmluZGV4IDY3MTI4YzEzYi4u ZjVmNGExNjFmIDEwMDY0NAotLS0gYS9ub25lL3Rlc3RzL3g4Ni9pbnNuX2ZwdS5zdGRvdXQuZXhw CisrKyBiL25vbmUvdGVzdHMveDg2L2luc25fZnB1LnN0ZG91dC5leHAKQEAgLTEsMyArMSw0IEBA Citmbm9wXzEgLi4uIG9rCiBmYWJzXzEgLi4uIG9rCiBmYWJzXzIgLi4uIG9rCiBmYWJzXzMgLi4u IG9rCg==