Date: Mon, 13 Apr 2015 01:42:25 +0000 (UTC) From: Mark Johnston <markj@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r281482 - in stable/10/sys/cddl/dev/dtrace: amd64 i386 Message-ID: <201504130142.t3D1gPA0047667@svn.freebsd.org>
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Author: markj Date: Mon Apr 13 01:42:24 2015 New Revision: 281482 URL: https://svnweb.freebsd.org/changeset/base/281482 Log: MFC r280834: Bound the number of frames traversed when executing the ustackdepth action. Modified: stable/10/sys/cddl/dev/dtrace/amd64/dtrace_isa.c stable/10/sys/cddl/dev/dtrace/i386/dtrace_isa.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/cddl/dev/dtrace/amd64/dtrace_isa.c ============================================================================== --- stable/10/sys/cddl/dev/dtrace/amd64/dtrace_isa.c Mon Apr 13 01:19:22 2015 (r281481) +++ stable/10/sys/cddl/dev/dtrace/amd64/dtrace_isa.c Mon Apr 13 01:42:24 2015 (r281482) @@ -49,6 +49,8 @@ uint16_t dtrace_fuword16_nocheck(void *) uint32_t dtrace_fuword32_nocheck(void *); uint64_t dtrace_fuword64_nocheck(void *); +int dtrace_ustackdepth_max = 2048; + void dtrace_getpcstack(pc_t *pcstack, int pcstack_limit, int aframes, uint32_t *intrpc) @@ -102,14 +104,25 @@ static int dtrace_getustack_common(uint64_t *pcstack, int pcstack_limit, uintptr_t pc, uintptr_t sp) { + uintptr_t oldsp; volatile uint16_t *flags = (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags; int ret = 0; ASSERT(pcstack == NULL || pcstack_limit > 0); + ASSERT(dtrace_ustackdepth_max > 0); while (pc != 0) { - ret++; + /* + * We limit the number of times we can go around this + * loop to account for a circular stack. + */ + if (ret++ >= dtrace_ustackdepth_max) { + *flags |= CPU_DTRACE_BADSTACK; + cpu_core[curcpu].cpuc_dtrace_illval = sp; + break; + } + if (pcstack != NULL) { *pcstack++ = (uint64_t)pc; pcstack_limit--; @@ -120,10 +133,18 @@ dtrace_getustack_common(uint64_t *pcstac if (sp == 0) break; + oldsp = sp; + pc = dtrace_fuword64((void *)(sp + offsetof(struct amd64_frame, f_retaddr))); sp = dtrace_fuword64((void *)sp); + if (sp == oldsp) { + *flags |= CPU_DTRACE_BADSTACK; + cpu_core[curcpu].cpuc_dtrace_illval = sp; + break; + } + /* * This is totally bogus: if we faulted, we're going to clear * the fault and break. This is to deal with the apparently Modified: stable/10/sys/cddl/dev/dtrace/i386/dtrace_isa.c ============================================================================== --- stable/10/sys/cddl/dev/dtrace/i386/dtrace_isa.c Mon Apr 13 01:19:22 2015 (r281481) +++ stable/10/sys/cddl/dev/dtrace/i386/dtrace_isa.c Mon Apr 13 01:42:24 2015 (r281482) @@ -55,6 +55,8 @@ uint16_t dtrace_fuword16_nocheck(void *) uint32_t dtrace_fuword32_nocheck(void *); uint64_t dtrace_fuword64_nocheck(void *); +int dtrace_ustackdepth_max = 2048; + void dtrace_getpcstack(pc_t *pcstack, int pcstack_limit, int aframes, uint32_t *intrpc) @@ -113,11 +115,13 @@ dtrace_getustack_common(uint64_t *pcstac uintptr_t oldcontext = lwp->lwp_oldcontext; /* XXX signal stack. */ size_t s1, s2; #endif + uintptr_t oldsp; volatile uint16_t *flags = (volatile uint16_t *)&cpu_core[curcpu].cpuc_dtrace_flags; int ret = 0; ASSERT(pcstack == NULL || pcstack_limit > 0); + ASSERT(dtrace_ustackdepth_max > 0); #ifdef notyet /* XXX signal stack. */ if (p->p_model == DATAMODEL_NATIVE) { @@ -130,7 +134,16 @@ dtrace_getustack_common(uint64_t *pcstac #endif while (pc != 0) { - ret++; + /* + * We limit the number of times we can go around this + * loop to account for a circular stack. + */ + if (ret++ >= dtrace_ustackdepth_max) { + *flags |= CPU_DTRACE_BADSTACK; + cpu_core[curcpu].cpuc_dtrace_illval = sp; + break; + } + if (pcstack != NULL) { *pcstack++ = (uint64_t)pc; pcstack_limit--; @@ -141,6 +154,8 @@ dtrace_getustack_common(uint64_t *pcstac if (sp == 0) break; + oldsp = sp; + #ifdef notyet /* XXX signal stack. */ if (oldcontext == sp + s1 || oldcontext == sp + s2) { if (p->p_model == DATAMODEL_NATIVE) { @@ -179,6 +194,12 @@ dtrace_getustack_common(uint64_t *pcstac sp = dtrace_fuword32((void *)sp); #endif /* ! notyet */ + if (sp == oldsp) { + *flags |= CPU_DTRACE_BADSTACK; + cpu_core[curcpu].cpuc_dtrace_illval = sp; + break; + } + /* * This is totally bogus: if we faulted, we're going to clear * the fault and break. This is to deal with the apparently
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