diff --git a/criu/arch/s390/crtools.c b/criu/arch/s390/crtools.c index 96cef819e..e08c83878 100644 --- a/criu/arch/s390/crtools.c +++ b/criu/arch/s390/crtools.c @@ -142,6 +142,29 @@ static void print_core_fp_regs(const char *msg, CoreEntry *core) print_core_ri_cb(core); } +/* + * Allocate floating point registers + */ +static UserS390FpregsEntry *allocate_fp_regs(void) +{ + UserS390FpregsEntry *fpregs; + + fpregs = xmalloc(sizeof(*fpregs)); + if (!fpregs) + return NULL; + user_s390_fpregs_entry__init(fpregs); + + fpregs->n_fprs = 16; + fpregs->fprs = xzalloc(16 * sizeof(uint64_t)); + if (!fpregs->fprs) + goto fail_free_fpregs; + return fpregs; + +fail_free_fpregs: + xfree(fpregs); + return NULL; +} + /* * Allocate VxrsLow registers */ @@ -294,7 +317,13 @@ int save_task_regs(pid_t pid, void *arg, user_regs_struct_t *u, user_fpregs_stru CoreEntry *core = arg; gpregs = CORE_THREAD_ARCH_INFO(core)->gpregs; - fpregs = CORE_THREAD_ARCH_INFO(core)->fpregs; + /* + * We delay allocating this until now because checkpointing can fail earlier. + * When it fails we need to know if we reached here or not so that the cleanup + * code doesn't restore FPRs that were never saved in the first place. + */ + fpregs = allocate_fp_regs(); + CORE_THREAD_ARCH_INFO(core)->fpregs = fpregs; /* Vector registers */ if (f->flags & USER_FPREGS_VXRS) { @@ -399,36 +428,15 @@ int restore_fpu(struct rt_sigframe *f, CoreEntry *core) return 0; } -/* - * Allocate floating point registers - */ -static UserS390FpregsEntry *allocate_fp_regs(void) -{ - UserS390FpregsEntry *fpregs; - - fpregs = xmalloc(sizeof(*fpregs)); - if (!fpregs) - return NULL; - user_s390_fpregs_entry__init(fpregs); - - fpregs->n_fprs = 16; - fpregs->fprs = xzalloc(16 * sizeof(uint64_t)); - if (!fpregs->fprs) - goto fail_free_fpregs; - return fpregs; - -fail_free_fpregs: - xfree(fpregs); - return NULL; -} - /* * Free floating point registers */ static void free_fp_regs(UserS390FpregsEntry *fpregs) { - xfree(fpregs->fprs); - xfree(fpregs); + if (fpregs) { + xfree(fpregs->fprs); + xfree(fpregs); + } } /* @@ -487,15 +495,17 @@ int arch_alloc_thread_info(CoreEntry *core) ti_s390->gpregs = allocate_gp_regs(); if (!ti_s390->gpregs) goto fail_free_ti_s390; - ti_s390->fpregs = allocate_fp_regs(); - if (!ti_s390->fpregs) - goto fail_free_gp_regs; + + /* + * Delay allocating space until needed. Checkpointing can fail before that + * and the cleanup code needs to be able to tell if FPRs were saved or not + * before trying to restore the register state. + */ + ti_s390->fpregs = NULL; CORE_THREAD_ARCH_INFO(core) = ti_s390; return 0; -fail_free_gp_regs: - free_gp_regs(ti_s390->gpregs); fail_free_ti_s390: xfree(ti_s390); return -1; @@ -678,14 +688,18 @@ static int set_task_regs(pid_t pid, CoreEntry *core) user_fpregs_struct_t fpregs; memset(&fpregs, 0, sizeof(fpregs)); - /* Floating point registers */ + /* + * Floating point registers + * Optional on checkpoint; checkpoint may have failed and we may reach here as part of cleanup + * so there's no guarantee that we saved FPRs for this thread. + */ cfpregs = CORE_THREAD_ARCH_INFO(core)->fpregs; - if (!cfpregs) - return -1; - fpregs.prfpreg.fpc = cfpregs->fpc; - memcpy(fpregs.prfpreg.fprs, cfpregs->fprs, sizeof(fpregs.prfpreg.fprs)); - if (set_fp_regs(pid, &fpregs) < 0) - return -1; + if (cfpregs) { + fpregs.prfpreg.fpc = cfpregs->fpc; + memcpy(fpregs.prfpreg.fprs, cfpregs->fprs, sizeof(fpregs.prfpreg.fprs)); + if (set_fp_regs(pid, &fpregs) < 0) + return -1; + } /* Vector registers (optional) */ cvxrs_low = CORE_THREAD_ARCH_INFO(core)->vxrs_low; if (cvxrs_low != NULL) {