/* * sortextable.h * * Copyright 2011 - 2012 Cavium, Inc. * * Some of this code was taken out of recordmcount.h written by: * * Copyright 2009 John F. Reiser . All rights reserved. * Copyright 2010 Steven Rostedt , Red Hat Inc. * * * Licensed under the GNU General Public License, version 2 (GPLv2). */ #undef extable_ent_size #undef compare_extable #undef do_func #undef Elf_Addr #undef Elf_Ehdr #undef Elf_Shdr #undef Elf_Rel #undef Elf_Rela #undef Elf_Sym #undef ELF_R_SYM #undef Elf_r_sym #undef ELF_R_INFO #undef Elf_r_info #undef ELF_ST_BIND #undef ELF_ST_TYPE #undef fn_ELF_R_SYM #undef fn_ELF_R_INFO #undef uint_t #undef _r #undef _w #ifdef SORTEXTABLE_64 # define extable_ent_size 16 # define compare_extable compare_extable_64 # define do_func do64 # define Elf_Addr Elf64_Addr # define Elf_Ehdr Elf64_Ehdr # define Elf_Shdr Elf64_Shdr # define Elf_Rel Elf64_Rel # define Elf_Rela Elf64_Rela # define Elf_Sym Elf64_Sym # define ELF_R_SYM ELF64_R_SYM # define Elf_r_sym Elf64_r_sym # define ELF_R_INFO ELF64_R_INFO # define Elf_r_info Elf64_r_info # define ELF_ST_BIND ELF64_ST_BIND # define ELF_ST_TYPE ELF64_ST_TYPE # define fn_ELF_R_SYM fn_ELF64_R_SYM # define fn_ELF_R_INFO fn_ELF64_R_INFO # define uint_t uint64_t # define _r r8 # define _w w8 #else # define extable_ent_size 8 # define compare_extable compare_extable_32 # define do_func do32 # define Elf_Addr Elf32_Addr # define Elf_Ehdr Elf32_Ehdr # define Elf_Shdr Elf32_Shdr # define Elf_Rel Elf32_Rel # define Elf_Rela Elf32_Rela # define Elf_Sym Elf32_Sym # define ELF_R_SYM ELF32_R_SYM # define Elf_r_sym Elf32_r_sym # define ELF_R_INFO ELF32_R_INFO # define Elf_r_info Elf32_r_info # define ELF_ST_BIND ELF32_ST_BIND # define ELF_ST_TYPE ELF32_ST_TYPE # define fn_ELF_R_SYM fn_ELF32_R_SYM # define fn_ELF_R_INFO fn_ELF32_R_INFO # define uint_t uint32_t # define _r r # define _w w #endif static int compare_extable(const void *a, const void *b) { Elf_Addr av = _r(a); Elf_Addr bv = _r(b); if (av < bv) return -1; if (av > bv) return 1; return 0; } static void do_func(Elf_Ehdr *ehdr, char const *const fname, table_sort_t custom_sort) { Elf_Shdr *shdr; Elf_Shdr *shstrtab_sec; Elf_Shdr *strtab_sec = NULL; Elf_Shdr *symtab_sec = NULL; Elf_Shdr *extab_sec = NULL; Elf_Sym *sym; const Elf_Sym *symtab; Elf32_Word *symtab_shndx_start = NULL; Elf_Sym *sort_needed_sym; Elf_Shdr *sort_needed_sec; Elf_Rel *relocs = NULL; int relocs_size = 0; uint32_t *sort_done_location; const char *secstrtab; const char *strtab; char *extab_image; int extab_index = 0; int i; int idx; unsigned int num_sections; unsigned int secindex_strings; shdr = (Elf_Shdr *)((char *)ehdr + _r(&ehdr->e_shoff)); num_sections = r2(&ehdr->e_shnum); if (num_sections == SHN_UNDEF) num_sections = _r(&shdr[0].sh_size); secindex_strings = r2(&ehdr->e_shstrndx); if (secindex_strings == SHN_XINDEX) secindex_strings = r(&shdr[0].sh_link); shstrtab_sec = shdr + secindex_strings; secstrtab = (const char *)ehdr + _r(&shstrtab_sec->sh_offset); for (i = 0; i < num_sections; i++) { idx = r(&shdr[i].sh_name); if (strcmp(secstrtab + idx, "__ex_table") == 0) { extab_sec = shdr + i; extab_index = i; } if ((r(&shdr[i].sh_type) == SHT_REL || r(&shdr[i].sh_type) == SHT_RELA) && r(&shdr[i].sh_info) == extab_index) { relocs = (void *)ehdr + _r(&shdr[i].sh_offset); relocs_size = _r(&shdr[i].sh_size); } if (strcmp(secstrtab + idx, ".symtab") == 0) symtab_sec = shdr + i; if (strcmp(secstrtab + idx, ".strtab") == 0) strtab_sec = shdr + i; if (r(&shdr[i].sh_type) == SHT_SYMTAB_SHNDX) symtab_shndx_start = (Elf32_Word *)( (const char *)ehdr + _r(&shdr[i].sh_offset)); } if (strtab_sec == NULL) { fprintf(stderr, "no .strtab in file: %s\n", fname); fail_file(); } if (symtab_sec == NULL) { fprintf(stderr, "no .symtab in file: %s\n", fname); fail_file(); } symtab = (const Elf_Sym *)((const char *)ehdr + _r(&symtab_sec->sh_offset)); if (extab_sec == NULL) { fprintf(stderr, "no __ex_table in file: %s\n", fname); fail_file(); } strtab = (const char *)ehdr + _r(&strtab_sec->sh_offset); extab_image = (void *)ehdr + _r(&extab_sec->sh_offset); if (custom_sort) { custom_sort(extab_image, _r(&extab_sec->sh_size)); } else { int num_entries = _r(&extab_sec->sh_size) / extable_ent_size; qsort(extab_image, num_entries, extable_ent_size, compare_extable); } /* If there were relocations, we no longer need them. */ if (relocs) memset(relocs, 0, relocs_size); /* find main_extable_sort_needed */ sort_needed_sym = NULL; for (i = 0; i < _r(&symtab_sec->sh_size) / sizeof(Elf_Sym); i++) { sym = (void *)ehdr + _r(&symtab_sec->sh_offset); sym += i; if (ELF_ST_TYPE(sym->st_info) != STT_OBJECT) continue; idx = r(&sym->st_name); if (strcmp(strtab + idx, "main_extable_sort_needed") == 0) { sort_needed_sym = sym; break; } } if (sort_needed_sym == NULL) { fprintf(stderr, "no main_extable_sort_needed symbol in file: %s\n", fname); fail_file(); } sort_needed_sec = &shdr[get_secindex(r2(&sym->st_shndx), sort_needed_sym - symtab, symtab_shndx_start)]; sort_done_location = (void *)ehdr + _r(&sort_needed_sec->sh_offset) + _r(&sort_needed_sym->st_value) - _r(&sort_needed_sec->sh_addr); #if 0 printf("sort done marker at %lx\n", (unsigned long)((char *)sort_done_location - (char *)ehdr)); #endif /* We sorted it, clear the flag. */ w(0, sort_done_location); } > /include/soc/fsl/qe/qe_tdm.h parent1b1bc42c1692e9b62756323c675a44cb1a1f9dbd (diff)
percpu-refcount: fix reference leak during percpu-atomic transition
percpu_ref_tryget() and percpu_ref_tryget_live() should return "true" IFF they acquire a reference. But the return value from atomic_long_inc_not_zero() is a long and may have high bits set, e.g. PERCPU_COUNT_BIAS, and the return value of the tryget routines is bool so the reference may actually be acquired but the routines return "false" which results in a reference leak since the caller assumes it does not need to do a corresponding percpu_ref_put(). This was seen when performing CPU hotplug during I/O, as hangs in blk_mq_freeze_queue_wait where percpu_ref_kill (blk_mq_freeze_queue_start) raced with percpu_ref_tryget (blk_mq_timeout_work). Sample stack trace: __switch_to+0x2c0/0x450 __schedule+0x2f8/0x970 schedule+0x48/0xc0 blk_mq_freeze_queue_wait+0x94/0x120 blk_mq_queue_reinit_work+0xb8/0x180 blk_mq_queue_reinit_prepare+0x84/0xa0 cpuhp_invoke_callback+0x17c/0x600 cpuhp_up_callbacks+0x58/0x150 _cpu_up+0xf0/0x1c0 do_cpu_up+0x120/0x150 cpu_subsys_online+0x64/0xe0 device_online+0xb4/0x120 online_store+0xb4/0xc0 dev_attr_store+0x68/0xa0 sysfs_kf_write+0x80/0xb0 kernfs_fop_write+0x17c/0x250 __vfs_write+0x6c/0x1e0 vfs_write+0xd0/0x270 SyS_write+0x6c/0x110 system_call+0x38/0xe0 Examination of the queue showed a single reference (no PERCPU_COUNT_BIAS, and __PERCPU_REF_DEAD, __PERCPU_REF_ATOMIC set) and no requests. However, conditions at the time of the race are count of PERCPU_COUNT_BIAS + 0 and __PERCPU_REF_DEAD and __PERCPU_REF_ATOMIC set. The fix is to make the tryget routines use an actual boolean internally instead of the atomic long result truncated to a int. Fixes: e625305b3907 percpu-refcount: make percpu_ref based on longs instead of ints Link: https://bugzilla.kernel.org/show_bug.cgi?id=190751 Signed-off-by: Douglas Miller <dougmill@linux.vnet.ibm.com> Reviewed-by: Jens Axboe <axboe@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: e625305b3907 ("percpu-refcount: make percpu_ref based on longs instead of ints") Cc: stable@vger.kernel.org # v3.18+
Diffstat (limited to 'include/soc/fsl/qe/qe_tdm.h')