From: Rusty Russell I've long disliked Linux's user access functions. Nonetheless, let's stop the warnings. Signed-off-by: Rusty Russell Signed-off-by: Andrew Morton --- drivers/lguest/core.c | 8 +++-- drivers/lguest/hypercalls.c | 33 ++++++++++++++++-------- drivers/lguest/interrupts_and_traps.c | 17 ++++++++---- 3 files changed, 39 insertions(+), 19 deletions(-) diff -puN drivers/lguest/core.c~lguest-the-host-code-remove-put_user-etc-warnings-add-bloat drivers/lguest/core.c --- a/drivers/lguest/core.c~lguest-the-host-code-remove-put_user-etc-warnings-add-bloat +++ a/drivers/lguest/core.c @@ -302,8 +302,9 @@ int run_guest(struct lguest *lg, char *_ /* Hypercalls first: we might have been out to userspace */ do_hypercalls(lg); if (lg->dma_is_pending) { - put_user(lg->pending_dma, (unsigned long *)user); - put_user(lg->pending_key, (unsigned long *)user+1); + if (put_user(lg->pending_dma, (unsigned long *)user) || + put_user(lg->pending_key, (unsigned long *)user+1)) + return -EFAULT; return sizeof(unsigned long)*2; } @@ -349,7 +350,8 @@ int run_guest(struct lguest *lg, char *_ continue; /* If lguest_data is NULL, this won't hurt. */ - put_user(cr2, &lg->lguest_data->cr2); + if (put_user(cr2, &lg->lguest_data->cr2)) + kill_guest(lg, "Writing cr2"); break; case 7: /* We've intercepted a Device Not Available fault. */ /* If they don't want to know, just absorb it. */ diff -puN drivers/lguest/hypercalls.c~lguest-the-host-code-remove-put_user-etc-warnings-add-bloat drivers/lguest/hypercalls.c --- a/drivers/lguest/hypercalls.c~lguest-the-host-code-remove-put_user-etc-warnings-add-bloat +++ a/drivers/lguest/hypercalls.c @@ -102,7 +102,9 @@ static void do_async_hcalls(struct lgues unsigned int i; u8 st[LHCALL_RING_SIZE]; - copy_from_user(&st, &lg->lguest_data->hcall_status, sizeof(st)); + if (copy_from_user(&st, &lg->lguest_data->hcall_status, sizeof(st))) + return; + for (i = 0; i < ARRAY_SIZE(st); i++) { struct lguest_regs regs; unsigned int n = lg->next_hcall; @@ -113,12 +115,20 @@ static void do_async_hcalls(struct lgues if (++lg->next_hcall == LHCALL_RING_SIZE) lg->next_hcall = 0; - get_user(regs.eax, &lg->lguest_data->hcalls[n].eax); - get_user(regs.edx, &lg->lguest_data->hcalls[n].edx); - get_user(regs.ecx, &lg->lguest_data->hcalls[n].ecx); - get_user(regs.ebx, &lg->lguest_data->hcalls[n].ebx); + if (get_user(regs.eax, &lg->lguest_data->hcalls[n].eax) + || get_user(regs.edx, &lg->lguest_data->hcalls[n].edx) + || get_user(regs.ecx, &lg->lguest_data->hcalls[n].ecx) + || get_user(regs.ebx, &lg->lguest_data->hcalls[n].ebx)) { + kill_guest(lg, "Fetching async hypercalls"); + break; + } + do_hcall(lg, ®s); - put_user(0xFF, &lg->lguest_data->hcall_status[n]); + if (put_user(0xFF, &lg->lguest_data->hcall_status[n])) { + kill_guest(lg, "Writing result for async hypercall"); + break; + } + if (lg->dma_is_pending) break; } @@ -139,11 +149,12 @@ static void initialize(struct lguest *lg kill_guest(lg, "bad guest page %p", lg->lguest_data); return; } - get_user(lg->noirq_start, &lg->lguest_data->noirq_start); - get_user(lg->noirq_end, &lg->lguest_data->noirq_end); - /* We reserve the top pgd entry. */ - put_user(4U*1024*1024, &lg->lguest_data->reserve_mem); - put_user(lg->guestid, &lg->lguest_data->guestid); + if (get_user(lg->noirq_start, &lg->lguest_data->noirq_start) + || get_user(lg->noirq_end, &lg->lguest_data->noirq_end) + /* We reserve the top pgd entry. */ + || put_user(4U*1024*1024, &lg->lguest_data->reserve_mem) + || put_user(lg->guestid, &lg->lguest_data->guestid)) + kill_guest(lg, "bad guest page %p", lg->lguest_data); } /* Even if we go out to userspace and come back, we don't want to do diff -puN drivers/lguest/interrupts_and_traps.c~lguest-the-host-code-remove-put_user-etc-warnings-add-bloat drivers/lguest/interrupts_and_traps.c --- a/drivers/lguest/interrupts_and_traps.c~lguest-the-host-code-remove-put_user-etc-warnings-add-bloat +++ a/drivers/lguest/interrupts_and_traps.c @@ -40,7 +40,8 @@ static void set_guest_interrupt(struct l /* We use IF bit in eflags to indicate whether irqs were disabled (it's always 0, since irqs are enabled when guest is running). */ eflags = lg->regs->eflags; - get_user(irq_enable, &lg->lguest_data->irq_enabled); + if (get_user(irq_enable, &lg->lguest_data->irq_enabled)) + irq_enable = 0; eflags |= (irq_enable & X86_EFLAGS_IF); push_guest_stack(lg, &gstack, eflags); @@ -58,7 +59,8 @@ static void set_guest_interrupt(struct l /* Disable interrupts for an interrupt gate. */ if (idt_type(lo, hi) == 0xE) - put_user(0, &lg->lguest_data->irq_enabled); + if (put_user(0, &lg->lguest_data->irq_enabled)) + kill_guest(lg, "Disabling interrupts"); } void maybe_do_interrupt(struct lguest *lg) @@ -75,7 +77,10 @@ void maybe_do_interrupt(struct lguest *l set_bit(0, lg->irqs_pending); /* Mask out any interrupts they have blocked. */ - copy_from_user(&blk, lg->lguest_data->blocked_interrupts, sizeof(blk)); + if (copy_from_user(&blk, lg->lguest_data->blocked_interrupts, + sizeof(blk))) + return; + bitmap_andnot(blk, lg->irqs_pending, blk, LGUEST_IRQS); irq = find_first_bit(blk, LGUEST_IRQS); @@ -88,12 +93,14 @@ void maybe_do_interrupt(struct lguest *l /* If they're halted, we re-enable interrupts. */ if (lg->halted) { /* Re-enable interrupts. */ - put_user(X86_EFLAGS_IF, &lg->lguest_data->irq_enabled); + if (put_user(X86_EFLAGS_IF, &lg->lguest_data->irq_enabled)) + kill_guest(lg, "Re-enabling interrupts"); lg->halted = 0; } else { /* Maybe they have interrupts disabled? */ u32 irq_enabled; - get_user(irq_enabled, &lg->lguest_data->irq_enabled); + if (get_user(irq_enabled, &lg->lguest_data->irq_enabled)) + irq_enabled = 0; if (!irq_enabled) return; } _