On Sep 18 2017, Jeff Law <l...@redhat.com> wrote: > On 09/18/2017 10:09 AM, Andreas Schwab wrote: >> On Sep 18 2017, Jeff Law <l...@redhat.com> wrote: >> >>> Can you confirm if the probe was in the red zone vs the live areas on >>> the stack? >> >> It overwrites a nearby variable. sp + 8 happens to be the address of >> file_entries_new_size. >> >> 0x000140e8 <+1172>: mov r6, sp >> 0x000140ec <+1176>: add r3, r3, #7 >> 0x000140f0 <+1180>: bic r3, r3, #7 >> 0x000140f4 <+1184>: cmp r3, #4096 ; 0x1000 >> 0x000140f8 <+1188>: bcc 0x14110 <save_cache+1212> >> 0x000140fc <+1192>: sub r3, r3, #4096 ; 0x1000 >> 0x00014100 <+1196>: sub sp, sp, #4096 ; 0x1000 >> 0x00014104 <+1200>: cmp r3, #4096 ; 0x1000 >> 0x00014108 <+1204>: str r0, [sp, #8] >> 0x0001410c <+1208>: bcs 0x140fc <save_cache+1192> >> 0x00014110 <+1212>: ldr r7, [r11, #-56] ; 0xffffffc8 >> 0x00014114 <+1216>: sub sp, sp, r3 >> 0x00014118 <+1220>: mov r1, #0 >> 0x0001411c <+1224>: add r3, sp, #8 >> 0x00014120 <+1228>: mov r0, r3 >> => 0x00014124 <+1232>: str r0, [sp, #8] >> >> Andreas. >> > Or better yet, include your .i and .s files in their entirety and the > gcc -v output
This was generated with a very simple and incomplete backport of -fstack-clash-protection to gcc7. What I get with your full patches with gcc8 looks correct. Andreas. -- Andreas Schwab, SUSE Labs, sch...@suse.de GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7 "And now for something completely different."
