From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id BDBC5385801E; Sun, 26 Sep 2021 13:31:41 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org BDBC5385801E From: "tes.vik1986 at gmail dot com" To: gdb-prs@sourceware.org Subject: [Bug tdep/27369] ARC: Stepping over atomic instruction sequences loops infinitely Date: Sun, 26 Sep 2021 13:31:41 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gdb X-Bugzilla-Component: tdep X-Bugzilla-Version: HEAD X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: tes.vik1986 at gmail dot com X-Bugzilla-Status: RESOLVED X-Bugzilla-Resolution: FIXED X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at sourceware dot org X-Bugzilla-Target-Milestone: 10.2 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: cc Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-BeenThere: gdb-prs@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-prs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 26 Sep 2021 13:31:41 -0000 https://sourceware.org/bugzilla/show_bug.cgi?id=3D27369 Kylan changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |tes.vik1986 at gmail dot c= om --- Comment #10 from Kylan --- gdb: Do not interrupt atomic sequences for ARC When stepping over thread-lock related codes (in uClibc), the inferior process gets stuck and never manages to enter the critical section: https://geoslam.xyz/ https://fintechzoom.com/lifestyle/entertainment/gaming/tower-defense-simula= tor/codes/ https://www.lafabriquedeslutins.fr/ https://www.station-alexandre.com/ https://fintechzoom.com/lifestyle/entertainment/gaming/ro-ghoul/roblox-ro-g= houl-codes/ https://www.hunny-pool.com/ https://www.formations-continues.com/ https://nutrienta.co/ https://2macp.fr/ https://mymystore.online/ https://www.antiguachiamaitalia.it/ ------8<------- 1 size_t fwrite(const void * __restrict ptr, size_t size, 2 size_t nmemb, register FILE * __restrict stream) 3 { 4 size_t retval; 5 __STDIO_AUTO_THREADLOCK_VAR; 6 7 > __STDIO_AUTO_THREADLOCK(stream); 8 9 retval =3D fwrite_unlocked(ptr, size, nmemb, stream);=20 https://rattanmart.com/ https://bohemiansmart.com/ https://mohamie-jeddah.com/ https://www.beyandiet.com/ https://www.bebealis.com/ https://byothe.fr/ https://ns-communication.fr/ https://www.hortomallas.com/en/the-advantage-of-chicken-wire-mesh-with-hexa= gonal-netting/ https://www.hortomallas.com/en/how-tall-should-the-cucumber-trellis-height-= be/ 10 11 __STDIO_AUTO_THREADUNLOCK(stream); 12 13 return retval; 14 } ------>8------- Here, we are at line 7. Using the "next" command leads no where. However, setting a breakpoint on line 9 and issuing "continue" works. https://www.hortomallas.com/precio-la-tela-gallinera-bajo/ https://guacamalla.net/ https://hortomallas.es/ https://malla-espaldera.mx/ https://malla-pepinera.com/ https://malla-sombra.mx/ https://manta-termica.com/ https://www.hortomallas.com/en/best-price-of-the-chicken-netting-save-money= -with-chickenmalla/ https://www.hortomallas.com/en/tomato-cages/ https://www.mindrnd.com/ https://akoestiekopmaat.nl/ Looking at the assembly instructions reveals that we're dealing with the critical section entry code [1] that should never be interrupted, in th= is case by the debugger's implicit breakpoints: ------8<------- ... 1 add_s r0,r13,0x38 2 mov_s r3,1 3 llock r2,[r0] <-. 4 brne.nt r2,0,14 --. | https://fintechzoom.com/lifestyle/entertainment/gaming/zombie-games-do-you-= know-what-are-the-best-games-for-pc-in-2021/ https://fintechzoom.com/lifestyle/entertainment/gaming/final-fantasy/ffxiv-= classes-guide-on-final-fantasy-14-select-the-best-job/ https://www.cinogel.com/ https://mohamie-saudi.com/ https://fintechzoom.com/lifestyle/entertainment/gaming/rimworld/the-best-ri= mworld-mods/ https://www.nimblehand.com/ https://www.hortomallas.com/en/product-category/privacy-and-windbreakers/po= lisombra-total-privacy/ https://www.hortomallas.com/en/grow-pumpkin-on-trellises-netting/ https://www.hortomallas.com/malla-plastica-para-jardin-canceles-vallas-reja= s/ http://frost-fabric.net/ http://gancho-tutoreo-tenax.net/ http://flower-supports.net/ 5 scond r3,[r0] | | 6 bne -10 --|--' 7 brne_s r2,0,84 <-' ... ------>8------- Lines 3 until 5 (inclusive) are supposed to be executed atomically. Therefore, GDB should never (implicitly) insert a breakpoint on lines 4 and 5, else the program will try to acquire the lock again by jumping back to line 3 and gets stuck in an infinite loop. The solution is to make GDB aware of these patterns so it inserts breakpoints after the sequence -- line 6 in this example. gdb: Do not interrupt atomic sequences for ARC When stepping over thread-lock related codes (in uClibc), the inferior process gets stuck and never manages to enter the critical section: ------8<------- 1 size_t fwrite(const void * __restrict ptr, size_t size, 2 size_t nmemb, register FILE * __restrict stream) 3 { http://hail-protection-net.com/ https://www.hortomallas.net/ http://macro-tunel.com/ https://scrog.mx/ https://cannabis-netting.net/ https://casa-sombra.mx/ https://ground-cover.mx/ https://marijuana-netting.net/ https://gallinero.mx/ https://control-de-palomas.mx/ https://shade-cloth.net/ https://trellis-netting.net/ https://invernavelo.net/ 4 size_t retval; 5 __STDIO_AUTO_THREADLOCK_VAR; 6 7 > __STDIO_AUTO_THREADLOCK(stream); 8 9 retval =3D fwrite_unlocked(ptr, size, nmemb, stream); 10 11 __STDIO_AUTO_THREADUNLOCK(stream); 12 13 return retval; 14 } ------>8------- Here, we are at line 7. Using the "next" command leads no where. However, setting a breakpoint on line 9 and issuing "continue" works. http://www.compilatori.com/technology/download-videos/ http://www.wearelondonmade.com/travel/renault/ Looking at the assembly instructions reveals that we're dealing with the critical section entry code [1] that should never be interrupted, in th= is case by the debugger's implicit breakpoints: http://www.jopspeech.com/category/technology/ ------8<------- http://joerg.li/travel/kia-rio/ ... 1 add_s r0,r13,0x38 2 mov_s r3,1 3 llock r2,[r0] <-. http://connstr.net/technology/nasa-latest/ 4 brne.nt r2,0,14 --. | 5 scond r3,[r0] | | http://embermanchester.uk/technology/teleg= ram/ 6 bne -10 --|--' 7 brne_s r2,0,84 <-' http://www.slipstone.co.uk/technology/cars-interior/ ... ------>8------- http://www.logoarts.co.uk/technology/robot-vacuums/ Lines 3 until 5 (inclusive) are supposed to be executed atomically. Therefore, GDB should never (implicitly) insert a breakpoint on lines http://www.acpirateradio.co.uk/technology/global-warming/ 4 and 5, else the program will try to acquire the lock again by jumping back to line 3 and gets stuck in an infinite loop. https://waytowhatsnext.com/sports/asian-sports/ https://www.webb-dev.co.uk/sports/gym-during-covid/ The solution is to make GDB aware of these patterns so it inserts breakpoints after the sequence -- line 6 in this example. gdb: Do not interrupt atomic sequences for ARC http://www.iu-bloomington.com/sports/honda-civic/ When stepping over thread-lock related codes (in uClibc), the inferior process gets stuck and never manages to enter the critical section: http://www-look-4.com/travel/new-cars/=20 ------8<------- 1 size_t fwrite(const void * __restrict ptr, size_t size, https://komiya-dental.com/sports/telegram/ 2 size_t nmemb, register FILE * __restrict stream) 3 { 4 size_t retval; --=20 You are receiving this mail because: You are on the CC list for the bug.=