Author: luporl Date: Mon Feb 4 16:02:03 2019 New Revision: 343744 URL: https://svnweb.freebsd.org/changeset/base/343744
Log: powerpc64: Add a trap stack area Currently, the trap code switches to the the temporary stack in the dbtrap section. It works in most cases, but in the beginning of the execution, the temp stack is being used, as starting in the powerpc_init() code. In this current scenario, the stack is being overwritten, which causes the return of breakpoint() to take abnormal execution. This current patchset create a small stack to use by the dbtrap: codepath avoiding the corruption of the temporary stack. PR: 224872 Submitted by: breno.leitao_gmail.com Reviewed by: jhibbits Differential Revision: https://reviews.freebsd.org/D14484 Modified: head/sys/powerpc/aim/locore32.S head/sys/powerpc/aim/locore64.S head/sys/powerpc/aim/trap_subr32.S head/sys/powerpc/aim/trap_subr64.S Modified: head/sys/powerpc/aim/locore32.S ============================================================================== --- head/sys/powerpc/aim/locore32.S Mon Feb 4 14:10:31 2019 (r343743) +++ head/sys/powerpc/aim/locore32.S Mon Feb 4 16:02:03 2019 (r343744) @@ -60,6 +60,12 @@ GLOBAL(__endkernel) GLOBAL(tmpstk) .space TMPSTKSZ +#ifdef KDB +#define TRAPSTKSZ 4096 /* 4k trap stack */ +GLOBAL(trapstk) + .space TRAPSTKSZ +#endif + .text .globl btext btext: Modified: head/sys/powerpc/aim/locore64.S ============================================================================== --- head/sys/powerpc/aim/locore64.S Mon Feb 4 14:10:31 2019 (r343743) +++ head/sys/powerpc/aim/locore64.S Mon Feb 4 16:02:03 2019 (r343744) @@ -65,6 +65,14 @@ GLOBAL(tmpstk) TOC_ENTRY(tmpstk) TOC_ENTRY(can_wakeup) +#ifdef KDB +#define TRAPSTKSZ 4096 /* 4k trap stack */ +GLOBAL(trapstk) + .space TRAPSTKSZ +TOC_ENTRY(trapstk) +#endif + + /* * Entry point for bootloaders that do not fully implement ELF and start * at the beginning of the image (kexec, notably). In its own section so Modified: head/sys/powerpc/aim/trap_subr32.S ============================================================================== --- head/sys/powerpc/aim/trap_subr32.S Mon Feb 4 14:10:31 2019 (r343743) +++ head/sys/powerpc/aim/trap_subr32.S Mon Feb 4 16:02:03 2019 (r343744) @@ -864,8 +864,8 @@ dbtrap: mtsprg3 %r1 lwz %r1,TRAP_TOCBASE(0) /* get new SP */ - lwz %r1,tmpstk@got(%r1) - addi %r1,%r1,TMPSTKSZ-16 + lwz %r1,trapstk@got(%r1) + addi %r1,%r1,TRAPSTKSZ-16 FRAME_SETUP(PC_DBSAVE) /* Call C trap code: */ Modified: head/sys/powerpc/aim/trap_subr64.S ============================================================================== --- head/sys/powerpc/aim/trap_subr64.S Mon Feb 4 14:10:31 2019 (r343743) +++ head/sys/powerpc/aim/trap_subr64.S Mon Feb 4 16:02:03 2019 (r343744) @@ -897,8 +897,8 @@ dbtrap: mtsprg3 %r1 GET_TOCBASE(%r1) /* get new SP */ - ld %r1,TOC_REF(tmpstk)(%r1) - addi %r1,%r1,(TMPSTKSZ-48) + ld %r1,TOC_REF(trapstk)(%r1) + addi %r1,%r1,(TRAPSTKSZ-48) FRAME_SETUP(PC_DBSAVE) /* Call C trap code: */ _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
