From 23fb064bb96f001ecb8682129f7ee1bc1ca691bc Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 21 Jul 2009 21:18:35 +0900 Subject: percpu: kill legacy percpu allocator With ia64 converted, there's no arch left which still uses legacy percpu allocator. Kill it. Signed-off-by: Tejun Heo Delightedly-acked-by: Rusty Russell Cc: Ingo Molnar Cc: Christoph Lameter --- kernel/module.c | 150 -------------------------------------------------------- 1 file changed, 150 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 8b7d8805819d..64787cddeb5e 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -370,8 +370,6 @@ EXPORT_SYMBOL_GPL(find_module); #ifdef CONFIG_SMP -#ifndef CONFIG_HAVE_LEGACY_PER_CPU_AREA - static void *percpu_modalloc(unsigned long size, unsigned long align, const char *name) { @@ -395,154 +393,6 @@ static void percpu_modfree(void *freeme) free_percpu(freeme); } -#else /* ... CONFIG_HAVE_LEGACY_PER_CPU_AREA */ - -/* Number of blocks used and allocated. */ -static unsigned int pcpu_num_used, pcpu_num_allocated; -/* Size of each block. -ve means used. */ -static int *pcpu_size; - -static int split_block(unsigned int i, unsigned short size) -{ - /* Reallocation required? */ - if (pcpu_num_used + 1 > pcpu_num_allocated) { - int *new; - - new = krealloc(pcpu_size, sizeof(new[0])*pcpu_num_allocated*2, - GFP_KERNEL); - if (!new) - return 0; - - pcpu_num_allocated *= 2; - pcpu_size = new; - } - - /* Insert a new subblock */ - memmove(&pcpu_size[i+1], &pcpu_size[i], - sizeof(pcpu_size[0]) * (pcpu_num_used - i)); - pcpu_num_used++; - - pcpu_size[i+1] -= size; - pcpu_size[i] = size; - return 1; -} - -static inline unsigned int block_size(int val) -{ - if (val < 0) - return -val; - return val; -} - -static void *percpu_modalloc(unsigned long size, unsigned long align, - const char *name) -{ - unsigned long extra; - unsigned int i; - void *ptr; - int cpu; - - if (align > PAGE_SIZE) { - printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n", - name, align, PAGE_SIZE); - align = PAGE_SIZE; - } - - ptr = __per_cpu_start; - for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) { - /* Extra for alignment requirement. */ - extra = ALIGN((unsigned long)ptr, align) - (unsigned long)ptr; - BUG_ON(i == 0 && extra != 0); - - if (pcpu_size[i] < 0 || pcpu_size[i] < extra + size) - continue; - - /* Transfer extra to previous block. */ - if (pcpu_size[i-1] < 0) - pcpu_size[i-1] -= extra; - else - pcpu_size[i-1] += extra; - pcpu_size[i] -= extra; - ptr += extra; - - /* Split block if warranted */ - if (pcpu_size[i] - size > sizeof(unsigned long)) - if (!split_block(i, size)) - return NULL; - - /* add the per-cpu scanning areas */ - for_each_possible_cpu(cpu) - kmemleak_alloc(ptr + per_cpu_offset(cpu), size, 0, - GFP_KERNEL); - - /* Mark allocated */ - pcpu_size[i] = -pcpu_size[i]; - return ptr; - } - - printk(KERN_WARNING "Could not allocate %lu bytes percpu data\n", - size); - return NULL; -} - -static void percpu_modfree(void *freeme) -{ - unsigned int i; - void *ptr = __per_cpu_start + block_size(pcpu_size[0]); - int cpu; - - /* First entry is core kernel percpu data. */ - for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) { - if (ptr == freeme) { - pcpu_size[i] = -pcpu_size[i]; - goto free; - } - } - BUG(); - - free: - /* remove the per-cpu scanning areas */ - for_each_possible_cpu(cpu) - kmemleak_free(freeme + per_cpu_offset(cpu)); - - /* Merge with previous? */ - if (pcpu_size[i-1] >= 0) { - pcpu_size[i-1] += pcpu_size[i]; - pcpu_num_used--; - memmove(&pcpu_size[i], &pcpu_size[i+1], - (pcpu_num_used - i) * sizeof(pcpu_size[0])); - i--; - } - /* Merge with next? */ - if (i+1 < pcpu_num_used && pcpu_size[i+1] >= 0) { - pcpu_size[i] += pcpu_size[i+1]; - pcpu_num_used--; - memmove(&pcpu_size[i+1], &pcpu_size[i+2], - (pcpu_num_used - (i+1)) * sizeof(pcpu_size[0])); - } -} - -static int percpu_modinit(void) -{ - pcpu_num_used = 2; - pcpu_num_allocated = 2; - pcpu_size = kmalloc(sizeof(pcpu_size[0]) * pcpu_num_allocated, - GFP_KERNEL); - /* Static in-kernel percpu data (used). */ - pcpu_size[0] = -(__per_cpu_end-__per_cpu_start); - /* Free room. */ - pcpu_size[1] = PERCPU_ENOUGH_ROOM + pcpu_size[0]; - if (pcpu_size[1] < 0) { - printk(KERN_ERR "No per-cpu room for modules.\n"); - pcpu_num_used = 1; - } - - return 0; -} -__initcall(percpu_modinit); - -#endif /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */ - static unsigned int find_pcpusec(Elf_Ehdr *hdr, Elf_Shdr *sechdrs, const char *secstrings) -- cgit v1.2.2 From c017b4be3e84176cab10eca5e6c4faeb8cfc6f3e Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Wed, 28 Oct 2009 13:33:09 +0000 Subject: kmemleak: Simplify the kmemleak_scan_area() function prototype This function was taking non-necessary arguments which can be determined by kmemleak. The patch also modifies the calling sites. Signed-off-by: Catalin Marinas Cc: Pekka Enberg Cc: Christoph Lameter Cc: Rusty Russell --- kernel/module.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 8b7d8805819d..1eb952097077 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2043,9 +2043,7 @@ static void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr, unsigned int i; /* only scan the sections containing data */ - kmemleak_scan_area(mod->module_core, (unsigned long)mod - - (unsigned long)mod->module_core, - sizeof(struct module), GFP_KERNEL); + kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL); for (i = 1; i < hdr->e_shnum; i++) { if (!(sechdrs[i].sh_flags & SHF_ALLOC)) @@ -2054,8 +2052,7 @@ static void kmemleak_load_module(struct module *mod, Elf_Ehdr *hdr, && strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) != 0) continue; - kmemleak_scan_area(mod->module_core, sechdrs[i].sh_addr - - (unsigned long)mod->module_core, + kmemleak_scan_area((void *)sechdrs[i].sh_addr, sechdrs[i].sh_size, GFP_KERNEL); } } -- cgit v1.2.2 From a6f5aa1ea05686ad6e84593a00a04161e6dfb3a3 Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Wed, 28 Oct 2009 13:33:10 +0000 Subject: kmemleak: Scan the _ftrace_events section in modules This section contains pointers to allocated objects and not scanning it leads to false positives. Reported-by: Zdenek Kabelac Acked-by: Rusty Russell Signed-off-by: Catalin Marinas --- kernel/module.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 1eb952097077..dd29ba43c34f 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2380,6 +2380,12 @@ static noinline struct module *load_module(void __user *umod, "_ftrace_events", sizeof(*mod->trace_events), &mod->num_trace_events); + /* + * This section contains pointers to allocated objects in the trace + * code and not scanning it leads to false positives. + */ + kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) * + mod->num_trace_events, GFP_KERNEL); #endif #ifdef CONFIG_FTRACE_MCOUNT_RECORD /* sechdrs[0].sh_size is always zero */ -- cgit v1.2.2 From 35dead4235e2b67da7275b4122fed37099c2f462 Mon Sep 17 00:00:00 2001 From: Helge Deller Date: Thu, 3 Dec 2009 00:29:15 +0100 Subject: modules: don't export section names of empty sections via sysfs On the parisc architecture we face for each and every loaded kernel module this kernel "badness warning": sysfs: cannot create duplicate filename '/module/ac97_bus/sections/.text' Badness at fs/sysfs/dir.c:487 Reason for that is, that on parisc all kernel modules do have multiple .text sections due to the usage of the -ffunction-sections compiler flag which is needed to reach all jump targets on this platform. An objdump on such a kernel module gives: Sections: Idx Name Size VMA LMA File off Algn 0 .note.gnu.build-id 00000024 00000000 00000000 00000034 2**2 CONTENTS, ALLOC, LOAD, READONLY, DATA 1 .text 00000000 00000000 00000000 00000058 2**0 CONTENTS, ALLOC, LOAD, READONLY, CODE 2 .text.ac97_bus_match 0000001c 00000000 00000000 00000058 2**2 CONTENTS, ALLOC, LOAD, READONLY, CODE 3 .text 00000000 00000000 00000000 000000d4 2**0 CONTENTS, ALLOC, LOAD, READONLY, CODE ... Since the .text sections are empty (size of 0 bytes) and won't be loaded by the kernel module loader anyway, I don't see a reason why such sections need to be listed under /sys/module//sections/ either. The attached patch does solve this issue by not exporting section names which are empty. This fixes bugzilla http://bugzilla.kernel.org/show_bug.cgi?id=14703 Signed-off-by: Helge Deller CC: rusty@rustcorp.com.au CC: akpm@linux-foundation.org CC: James.Bottomley@HansenPartnership.com CC: roland@redhat.com CC: dave@hiauly1.hia.nrc.ca Signed-off-by: Linus Torvalds --- kernel/module.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 8b7d8805819d..5842a71cf052 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1187,7 +1187,8 @@ static void add_sect_attrs(struct module *mod, unsigned int nsect, /* Count loaded sections and allocate structures */ for (i = 0; i < nsect; i++) - if (sechdrs[i].sh_flags & SHF_ALLOC) + if (sechdrs[i].sh_flags & SHF_ALLOC + && sechdrs[i].sh_size) nloaded++; size[0] = ALIGN(sizeof(*sect_attrs) + nloaded * sizeof(sect_attrs->attrs[0]), @@ -1207,6 +1208,8 @@ static void add_sect_attrs(struct module *mod, unsigned int nsect, for (i = 0; i < nsect; i++) { if (! (sechdrs[i].sh_flags & SHF_ALLOC)) continue; + if (!sechdrs[i].sh_size) + continue; sattr->address = sechdrs[i].sh_addr; sattr->name = kstrdup(secstrings + sechdrs[i].sh_name, GFP_KERNEL); -- cgit v1.2.2 From d4703aefdbc8f9f347f6dcefcddd791294314eb7 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 15 Dec 2009 16:28:32 -0600 Subject: module: handle ppc64 relocating kcrctabs when CONFIG_RELOCATABLE=y powerpc applies relocations to the kcrctab. They're absolute symbols, but it's not completely unreasonable: other archs may too, but the relocation is often 0. http://lists.ozlabs.org/pipermail/linuxppc-dev/2009-November/077972.html Inspired-by: Neil Horman Signed-off-by: Rusty Russell Tested-by: Neil Horman Acked-by: Paul Mackerras --- kernel/module.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-) (limited to 'kernel/module.c') diff --git a/kernel/module.c b/kernel/module.c index 12afc5a3ddd3..a65dc787a27b 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -880,11 +880,23 @@ static int try_to_force_load(struct module *mod, const char *reason) } #ifdef CONFIG_MODVERSIONS +/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */ +static unsigned long maybe_relocated(unsigned long crc, + const struct module *crc_owner) +{ +#ifdef ARCH_RELOCATES_KCRCTAB + if (crc_owner == NULL) + return crc - (unsigned long)reloc_start; +#endif + return crc; +} + static int check_version(Elf_Shdr *sechdrs, unsigned int versindex, const char *symname, struct module *mod, - const unsigned long *crc) + const unsigned long *crc, + const struct module *crc_owner) { unsigned int i, num_versions; struct modversion_info *versions; @@ -905,10 +917,10 @@ static int check_version(Elf_Shdr *sechdrs, if (strcmp(versions[i].name, symname) != 0) continue; - if (versions[i].crc == *crc) + if (versions[i].crc == maybe_relocated(*crc, crc_owner)) return 1; DEBUGP("Found checksum %lX vs module %lX\n", - *crc, versions[i].crc); + maybe_relocated(*crc, crc_owner), versions[i].crc); goto bad_version; } @@ -931,7 +943,8 @@ static inline int check_modstruct_version(Elf_Shdr *sechdrs, if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL, &crc, true, false)) BUG(); - return check_version(sechdrs, versindex, "module_layout", mod, crc); + return check_version(sechdrs, versindex, "module_layout", mod, crc, + NULL); } /* First part is kernel version, which we ignore if module has crcs. */ @@ -949,7 +962,8 @@ static inline int check_version(Elf_Shdr *sechdrs, unsigned int versindex, const char *symname, struct module *mod, - const unsigned long *crc) + const unsigned long *crc, + const struct module *crc_owner) { return 1; } @@ -984,8 +998,8 @@ static const struct kernel_symbol *resolve_symbol(Elf_Shdr *sechdrs, /* use_module can fail due to OOM, or module initialization or unloading */ if (sym) { - if (!check_version(sechdrs, versindex, name, mod, crc) || - !use_module(mod, owner)) + if (!check_version(sechdrs, versindex, name, mod, crc, owner) + || !use_module(mod, owner)) sym = NULL; } return sym; -- cgit v1.2.2