From: Rusty Russell Christoph Hellwig said runs sparse: 1) page_tables.c unnecessary initialization 2) Change prototype of run_lguest and do cast in caller instead (when we add __user to cast, it runs over another line). Al Viro pointed out the ugly cast in push_lguest_stack(): 3) Stick with unsigned long for arg, removes 4 casts in total. Most importantly, I now realize that Christoph's incorrect ranting about lgread_u32 et al was in fact a subtle ploy to make me diagnose the real issue: sparse 0.3 complains about casting a __user pointer to/from u32, but not an "unsigned long". They are (currently) equivalent for lguest, but this is a much better solution than __force. Kudos, Christoph, for such masterful manipulation! Signed-off-by: Rusty Russell Cc: Christoph Hellwig Signed-off-by: Andrew Morton --- drivers/lguest/core.c | 27 +++++++++--------- drivers/lguest/hypercalls.c | 10 ++---- drivers/lguest/interrupts_and_traps.c | 13 ++++---- drivers/lguest/io.c | 2 - drivers/lguest/lg.h | 35 +++++++++++------------- drivers/lguest/segments.c | 6 ++-- include/linux/lguest_launcher.h | 2 - 7 files changed, 47 insertions(+), 48 deletions(-) diff -puN drivers/lguest/core.c~lguest-the-host-code-tidyups-update drivers/lguest/core.c --- a/drivers/lguest/core.c~lguest-the-host-code-tidyups-update +++ a/drivers/lguest/core.c @@ -212,39 +212,40 @@ int lguest_address_ok(const struct lgues } /* Just like get_user, but don't let guest access lguest binary. */ -u32 lgread_u32(struct lguest *lg, u32 addr) +u32 lgread_u32(struct lguest *lg, unsigned long addr) { u32 val = 0; /* Don't let them access lguest binary */ if (!lguest_address_ok(lg, addr, sizeof(val)) - || get_user(val, (__force u32 __user *)addr) != 0) - kill_guest(lg, "bad read address %u", addr); + || get_user(val, (u32 __user *)addr) != 0) + kill_guest(lg, "bad read address %#lx", addr); return val; } -void lgwrite_u32(struct lguest *lg, u32 addr, u32 val) +void lgwrite_u32(struct lguest *lg, unsigned long addr, u32 val) { if (!lguest_address_ok(lg, addr, sizeof(val)) - || put_user(val, (__force u32 __user *)addr) != 0) - kill_guest(lg, "bad write address %u", addr); + || put_user(val, (u32 __user *)addr) != 0) + kill_guest(lg, "bad write address %#lx", addr); } -void lgread(struct lguest *lg, void *b, u32 addr, unsigned bytes) +void lgread(struct lguest *lg, void *b, unsigned long addr, unsigned bytes) { if (!lguest_address_ok(lg, addr, bytes) - || copy_from_user(b, (__force void __user *)addr, bytes) != 0) { + || copy_from_user(b, (void __user *)addr, bytes) != 0) { /* copy_from_user should do this, but as we rely on it... */ memset(b, 0, bytes); - kill_guest(lg, "bad read address %u len %u", addr, bytes); + kill_guest(lg, "bad read address %#lx len %u", addr, bytes); } } -void lgwrite(struct lguest *lg, u32 addr, const void *b, unsigned bytes) +void lgwrite(struct lguest *lg, unsigned long addr, const void *b, + unsigned bytes) { if (!lguest_address_ok(lg, addr, bytes) - || copy_to_user((__force void __user *)addr, b, bytes) != 0) - kill_guest(lg, "bad write address %u len %u", addr, bytes); + || copy_to_user((void __user *)addr, b, bytes) != 0) + kill_guest(lg, "bad write address %#lx len %u", addr, bytes); } static void set_ts(void) @@ -367,7 +368,7 @@ int run_guest(struct lguest *lg, unsigne if (deliver_trap(lg, lg->regs->trapnum)) continue; - kill_guest(lg, "unhandled trap %i at %#x (%#x)", + kill_guest(lg, "unhandled trap %li at %#lx (%#lx)", lg->regs->trapnum, lg->regs->eip, lg->regs->trapnum == 14 ? cr2 : lg->regs->errcode); } diff -puN drivers/lguest/hypercalls.c~lguest-the-host-code-tidyups-update drivers/lguest/hypercalls.c --- a/drivers/lguest/hypercalls.c~lguest-the-host-code-tidyups-update +++ a/drivers/lguest/hypercalls.c @@ -83,8 +83,7 @@ static void do_hcall(struct lguest *lg, guest_set_pmd(lg, regs->edx, regs->ebx); break; case LHCALL_LOAD_TLS: - guest_load_tls(lg, - (__force struct desc_struct __user*)regs->edx); + guest_load_tls(lg, regs->edx); break; case LHCALL_TS: lg->ts = regs->edx; @@ -93,7 +92,7 @@ static void do_hcall(struct lguest *lg, lg->halted = 1; break; default: - kill_guest(lg, "Bad hypercall %i\n", regs->eax); + kill_guest(lg, "Bad hypercall %li\n", regs->eax); } } @@ -138,15 +137,14 @@ static void do_async_hcalls(struct lgues static void initialize(struct lguest *lg) { if (lg->regs->eax != LHCALL_LGUEST_INIT) { - kill_guest(lg, "hypercall %i before LGUEST_INIT", + kill_guest(lg, "hypercall %li before LGUEST_INIT", lg->regs->eax); return; } lg->lguest_data = (struct lguest_data __user *)lg->regs->edx; /* We check here so we can simply copy_to_user/from_user */ - if (!lguest_address_ok(lg, (long)lg->lguest_data, - sizeof(*lg->lguest_data))) { + if (!lguest_address_ok(lg, lg->regs->edx, sizeof(*lg->lguest_data))) { kill_guest(lg, "bad guest page %p", lg->lguest_data); return; } diff -puN drivers/lguest/interrupts_and_traps.c~lguest-the-host-code-tidyups-update drivers/lguest/interrupts_and_traps.c --- a/drivers/lguest/interrupts_and_traps.c~lguest-the-host-code-tidyups-update +++ a/drivers/lguest/interrupts_and_traps.c @@ -16,24 +16,25 @@ static int idt_present(u32 lo, u32 hi) return (hi & 0x8000); } -static void push_guest_stack(struct lguest *lg, u32 __user **gstack, u32 val) +static void push_guest_stack(struct lguest *lg, unsigned long *gstack, u32 val) { - lgwrite_u32(lg, (__force u32)--(*gstack), val); + *gstack -= 4; + lgwrite_u32(lg, *gstack, val); } static void set_guest_interrupt(struct lguest *lg, u32 lo, u32 hi, int has_err) { - u32 __user *gstack; + unsigned long gstack; u32 eflags, ss, irq_enable; /* If they want a ring change, we use new stack and push old ss/esp */ if ((lg->regs->ss&0x3) != GUEST_PL) { - gstack = (u32 __user *)guest_pa(lg, lg->esp1); + gstack = guest_pa(lg, lg->esp1); ss = lg->ss1; push_guest_stack(lg, &gstack, lg->regs->ss); push_guest_stack(lg, &gstack, lg->regs->esp); } else { - gstack = (u32 __user *)guest_pa(lg, lg->regs->esp); + gstack = guest_pa(lg, lg->regs->esp); ss = lg->regs->ss; } @@ -53,7 +54,7 @@ static void set_guest_interrupt(struct l /* Change the real stack so switcher returns to trap handler */ lg->regs->ss = ss; - lg->regs->esp = (__force u32)gstack + lg->page_offset; + lg->regs->esp = gstack + lg->page_offset; lg->regs->cs = (__KERNEL_CS|GUEST_PL); lg->regs->eip = idt_address(lo, hi); diff -puN drivers/lguest/io.c~lguest-the-host-code-tidyups-update drivers/lguest/io.c --- a/drivers/lguest/io.c~lguest-the-host-code-tidyups-update +++ a/drivers/lguest/io.c @@ -52,7 +52,7 @@ static int check_dma_list(struct lguest return 1; kill: - kill_guest(lg, "bad DMA entry: %u@%#x", dma->len[i], dma->addr[i]); + kill_guest(lg, "bad DMA entry: %u@%#lx", dma->len[i], dma->addr[i]); return 0; } diff -puN drivers/lguest/lg.h~lguest-the-host-code-tidyups-update drivers/lguest/lg.h --- a/drivers/lguest/lg.h~lguest-the-host-code-tidyups-update +++ a/drivers/lguest/lg.h @@ -25,18 +25,18 @@ struct lguest_regs { /* Manually saved part. */ - u32 ebx, ecx, edx; - u32 esi, edi, ebp; - u32 gs; - u32 eax; - u32 fs, ds, es; - u32 trapnum, errcode; + unsigned long ebx, ecx, edx; + unsigned long esi, edi, ebp; + unsigned long gs; + unsigned long eax; + unsigned long fs, ds, es; + unsigned long trapnum, errcode; /* Trap pushed part */ - u32 eip; - u32 cs; - u32 eflags; - u32 esp; - u32 ss; + unsigned long eip; + unsigned long cs; + unsigned long eflags; + unsigned long esp; + unsigned long ss; }; void free_pagetables(void); @@ -175,10 +175,10 @@ extern struct lguest lguests[]; extern struct mutex lguest_lock; /* core.c: */ -u32 lgread_u32(struct lguest *lg, u32 addr); -void lgwrite_u32(struct lguest *lg, u32 val, u32 addr); -void lgread(struct lguest *lg, void *buf, u32 addr, unsigned bytes); -void lgwrite(struct lguest *lg, u32 addr, const void *buf, unsigned bytes); +u32 lgread_u32(struct lguest *lg, unsigned long addr); +void lgwrite_u32(struct lguest *lg, unsigned long addr, u32 val); +void lgread(struct lguest *lg, void *buf, unsigned long addr, unsigned len); +void lgwrite(struct lguest *lg, unsigned long, const void *buf, unsigned len); int find_free_guest(void); int lguest_address_ok(const struct lguest *lg, unsigned long addr, unsigned long len); @@ -199,9 +199,8 @@ void copy_traps(const struct lguest *lg, /* segments.c: */ void setup_default_gdt_entries(struct lguest_ro_state *state); void setup_guest_gdt(struct lguest *lg); -void load_guest_gdt(struct lguest *lg, u32 table, u32 num); -void guest_load_tls(struct lguest *lg, - const struct desc_struct __user *tls_array); +void load_guest_gdt(struct lguest *lg, unsigned long table, u32 num); +void guest_load_tls(struct lguest *lg, unsigned long tls_array); void copy_gdt(const struct lguest *lg, struct desc_struct *gdt); /* page_tables.c: */ diff -puN drivers/lguest/segments.c~lguest-the-host-code-tidyups-update drivers/lguest/segments.c --- a/drivers/lguest/segments.c~lguest-the-host-code-tidyups-update +++ a/drivers/lguest/segments.c @@ -95,7 +95,7 @@ void copy_gdt(const struct lguest *lg, s gdt[i] = lg->gdt[i]; } -void load_guest_gdt(struct lguest *lg, u32 table, u32 num) +void load_guest_gdt(struct lguest *lg, unsigned long table, u32 num) { if (num > ARRAY_SIZE(lg->gdt)) kill_guest(lg, "too many gdt entries %i", num); @@ -105,11 +105,11 @@ void load_guest_gdt(struct lguest *lg, u lg->changed |= CHANGED_GDT; } -void guest_load_tls(struct lguest *lg, const struct desc_struct __user *gtls) +void guest_load_tls(struct lguest *lg, unsigned long gtls) { struct desc_struct *tls = &lg->gdt[GDT_ENTRY_TLS_MIN]; - lgread(lg, tls, (u32)gtls, sizeof(*tls)*GDT_ENTRY_TLS_ENTRIES); + lgread(lg, tls, gtls, sizeof(*tls)*GDT_ENTRY_TLS_ENTRIES); fixup_gdt_table(lg); lg->changed |= CHANGED_GDT; } diff -puN include/linux/lguest_launcher.h~lguest-the-host-code-tidyups-update include/linux/lguest_launcher.h --- a/include/linux/lguest_launcher.h~lguest-the-host-code-tidyups-update +++ a/include/linux/lguest_launcher.h @@ -13,7 +13,7 @@ struct lguest_dma { /* 0 if free to be used, filled by hypervisor. */ u32 used_len; - u32 addr[LGUEST_MAX_DMA_SECTIONS]; + unsigned long addr[LGUEST_MAX_DMA_SECTIONS]; u16 len[LGUEST_MAX_DMA_SECTIONS]; }; _