Re: [Crash-utility] [PATCH v2] Remove the VOID_PTR facilitator macro

I've been wondering about the intended use of this facilitator macro for some time and concluded that it is plainly wrong. It should take a pointer value from a buffer, but what is the use of a pointer that pointed to something on the target machine? Since it cannot be meaningfully dereferenced on the host, the only (arguable) advantage is the ability to do pointer arithmetics on the variables. This second patch does the correct thing wherever pointer arithmetics was done, making the actual calculations more explicit. Signed-off-by: Petr Tesarik <ptesarik(a)suse.cz&gt;

--- memory.c | 47 +++++++++++++++++++++++++---------------------- 1 file changed, 25 insertions(+), 22 deletions(-) --- a/memory.c +++ b/memory.c @@ -26,8 +26,8 @@ struct meminfo { /* general pu ulong c_offset; ulong c_num; ulong s_mem; - void *s_freep; - ulong *s_index; + ulong s_freep; + ulong s_index; ulong s_inuse; ulong cpucached_cache; ulong cpucached_slab; @@ -139,7 +139,7 @@ static int next_kpage(ulong, ulong *); static ulong last_vmalloc_address(void); static ulong next_vmlist_vaddr(ulong); static int next_identity_mapping(ulong, ulong *); -static int vm_area_page_dump(ulong, ulong, ulong, ulong, void *, +static int vm_area_page_dump(ulong, ulong, ulong, ulong, ulong, struct reference *); static int dump_swap_info(ulong, ulong *, ulong *); static void swap_info_init(void); @@ -3138,7 +3138,7 @@ vm_area_dump(ulong task, ulong flag, ulo ulong vma; ulong vm_start; ulong vm_end; - void *vm_next, *vm_mm; + ulong vm_next, vm_mm; char *dentry_buf, *vma_buf, *file_buf; ulong vm_flags; ulong vm_file, inode; @@ -3202,7 +3202,7 @@ vm_area_dump(ulong task, ulong flag, ulo !DO_REF_SEARCH(ref)) fprintf(fp, vma_header); - for (found = FALSE; vma; vma = (ulong)vm_next) { + for (found = FALSE; vma; vma = vm_next) { if ((flag & PHYSADDR) && !DO_REF_SEARCH(ref)) fprintf(fp, "%s", vma_header); @@ -3211,9 +3211,9 @@ vm_area_dump(ulong task, ulong flag, ulo BZERO(buf1, BUFSIZE); vma_buf = fill_vma_cache(vma); - vm_mm = VOID_PTR(vma_buf + OFFSET(vm_area_struct_vm_mm)); + vm_mm = ULONG(vma_buf + OFFSET(vm_area_struct_vm_mm)); vm_end = ULONG(vma_buf + OFFSET(vm_area_struct_vm_end)); - vm_next = VOID_PTR(vma_buf + OFFSET(vm_area_struct_vm_next)); + vm_next = ULONG(vma_buf + OFFSET(vm_area_struct_vm_next)); vm_start = ULONG(vma_buf + OFFSET(vm_area_struct_vm_start)); vm_flags = SIZE(vm_area_struct_vm_flags) == sizeof(short) ? USHORT(vma_buf+ OFFSET(vm_area_struct_vm_flags)) : @@ -3335,7 +3335,7 @@ vm_area_page_dump(ulong vma, ulong task, ulong start, ulong end, - void *mm, + ulong mm, struct reference *ref) { physaddr_t paddr; @@ -3347,7 +3347,7 @@ vm_area_page_dump(ulong vma, char buf3[BUFSIZE]; char buf4[BUFSIZE]; - if ((ulong)mm == symbol_value("init_mm")) + if (mm == symbol_value("init_mm")) return FALSE; if (!ref || DO_REF_DISPLAY(ref)) @@ -9720,9 +9720,9 @@ dump_slab(struct meminfo *si) return; } - si->s_freep = VOID_PTR(si->slab_buf + OFFSET(kmem_slab_s_s_freep)); + si->s_freep = ULONG(si->slab_buf + OFFSET(kmem_slab_s_s_freep)); si->s_inuse = ULONG(si->slab_buf + OFFSET(kmem_slab_s_s_inuse)); - si->s_index = ULONG_PTR(si->slab_buf + OFFSET(kmem_slab_s_s_index)); + si->s_index = ULONG(si->slab_buf + OFFSET(kmem_slab_s_s_index)); s_offset = USHORT(si->slab_buf + OFFSET(kmem_slab_s_s_offset)); if (!(si->flags & ADDRESS_SPECIFIED)) { @@ -9850,7 +9850,7 @@ dump_slab_percpu_v2(struct meminfo *si) static void gather_slab_free_list(struct meminfo *si) { - ulong *next, obj; + ulong next, obj; ulong expected, cnt; BNEG(si->addrlist, sizeof(ulong) * (si->c_num+1)); @@ -9885,16 +9885,18 @@ gather_slab_free_list(struct meminfo *si */ if (si->c_flags & SLAB_CFLGS_BUFCTL) - obj = si->s_mem + ((next - si->s_index) * si->c_offset); + obj = si->s_mem + + ((next - si->s_index) / sizeof(ulong) + * si->c_offset); else - obj = (ulong)next - si->c_offset; + obj = next - si->c_offset; si->addrlist[cnt] = obj; if (si->flags & ADDRESS_SPECIFIED) { if (INSLAB(next, si) && - (si->spec_addr >= (ulong)next) && - (si->spec_addr < (ulong)(next + 1))) { + (si->spec_addr >= next) && + (si->spec_addr < next + sizeof(ulong))) { si->found = KMEM_BUFCTL_ADDR; return; } @@ -9909,7 +9911,7 @@ gather_slab_free_list(struct meminfo *si si->errors++; } - readmem((ulong)next, KVADDR, &next, sizeof(void *), + readmem(next, KVADDR, &next, sizeof(ulong), "s_freep chain entry", FAULT_ON_ERROR); } while (next); @@ -10057,7 +10059,7 @@ static void dump_slab_objects(struct meminfo *si) { int i, j; - ulong *next; + ulong next; int on_free_list; ulong cnt, expected; ulong bufctl, obj; @@ -10088,7 +10090,8 @@ dump_slab_objects(struct meminfo *si) if (si->c_flags & SLAB_CFLGS_BUFCTL) { for (i = 0, next = si->s_index; i < si->c_num; i++, next++) { obj = si->s_mem + - ((next - si->s_index) * si->c_offset); + ((next - si->s_index) / sizeof(ulong) + * si->c_offset); DUMP_SLAB_OBJECT(); } } else { @@ -11561,7 +11564,7 @@ next_upage(struct task_context *tc, ulon int found; char *vma_buf; ulong vm_start, vm_end; - void *vm_next; + ulong vm_next; if (!tc->mm_struct) return FALSE; @@ -11575,12 +11578,12 @@ next_upage(struct task_context *tc, ulon vaddr = VIRTPAGEBASE(vaddr) + PAGESIZE(); /* first possible page */ - for (found = FALSE; vma; vma = (ulong)vm_next) { + for (found = FALSE; vma; vma = vm_next) { vma_buf = fill_vma_cache(vma); vm_start = ULONG(vma_buf + OFFSET(vm_area_struct_vm_start)); vm_end = ULONG(vma_buf + OFFSET(vm_area_struct_vm_end)); - vm_next = VOID_PTR(vma_buf + OFFSET(vm_area_struct_vm_next)); + vm_next = ULONG(vma_buf + OFFSET(vm_area_struct_vm_next)); if (vaddr <= vm_start) { *nextvaddr = vm_start; -- Crash-utility mailing list Crash-utility(a)redhat.com https://www.redhat.com/mailman/listinfo/crash-utility