Brad Bishop | 26bdd44 | 2019-08-16 17:08:17 -0400 | [diff] [blame^] | 1 | From 43fb9cec1749b337bfa252fc2c1b0288847e8fa7 Mon Sep 17 00:00:00 2001 |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 2 | From: Andrea Adami <andrea.adami@gmail.com> |
| 3 | Date: Wed, 18 Apr 2018 02:21:30 +0200 |
| 4 | Subject: [PATCH] crashdump-elf.c: work around for _SC_NPROCESSORS_CONF |
| 5 | |
| 6 | klibc sysconf lacks this so the implementation |
| 7 | of Linus Torvalds was taken (simplified): |
| 8 | |
| 9 | https://sourceware.org/ml/libc-alpha/2011-06/msg00079.html |
| 10 | |
| 11 | Have fun reding the thread! |
| 12 | |
| 13 | Fix |
| 14 | |
| 15 | crashdump-elf.c:117:21: error: '_SC_NPROCESSORS_CONF' undeclared |
| 16 | |
| 17 | Upstream-Status: Inappropriate [klibc specific] |
| 18 | Signed-off-by: Andrea Adami <andrea.adami@gmail.com> |
| 19 | |
| 20 | --- |
Brad Bishop | 26bdd44 | 2019-08-16 17:08:17 -0400 | [diff] [blame^] | 21 | kexec/crashdump-elf.c | 92 +++++++++++++++++++++++++++++++++++++++++++ |
Brad Bishop | 1a4b7ee | 2018-12-16 17:11:34 -0800 | [diff] [blame] | 22 | 1 file changed, 92 insertions(+) |
| 23 | |
| 24 | diff --git a/kexec/crashdump-elf.c b/kexec/crashdump-elf.c |
| 25 | index b8bb686..7e6767c 100644 |
| 26 | --- a/kexec/crashdump-elf.c |
| 27 | +++ b/kexec/crashdump-elf.c |
| 28 | @@ -25,6 +25,94 @@ do { \ |
| 29 | } while(0) |
| 30 | #endif |
| 31 | |
| 32 | +#ifdef __KLIBC__ |
| 33 | +#ifndef KLIBC_SYSFS_CPU_H |
| 34 | +#define KLIBC_SYSFS_CPU_H |
| 35 | + |
| 36 | + |
| 37 | +static int __get_sysfs_cpus(const char *path); |
| 38 | +int __get_nprocs (void); |
| 39 | +int __get_nprocs_conf (void); |
| 40 | + |
| 41 | + |
| 42 | + |
| 43 | +static int __get_sysfs_cpus(const char *path) |
| 44 | +{ |
| 45 | + FILE *file; |
| 46 | + int nr_cpus = 0; |
| 47 | + int prev = -1; |
| 48 | + char *p; |
| 49 | + char line[10]; |
| 50 | + |
| 51 | + |
| 52 | + file = fopen(path, "r"); |
| 53 | + if (!file) |
| 54 | + return -1; |
| 55 | + for (;;) { |
| 56 | + char sep; |
| 57 | + int cpu; |
| 58 | + int n; |
| 59 | + |
| 60 | + /* int n = fscanf(file, "%u%c", &cpu, &sep); */ |
| 61 | + p = fgets(line, sizeof(line), file); |
| 62 | + if (p == NULL) |
| 63 | + return -1; |
| 64 | + else |
| 65 | + n = sscanf(line, "%u%c", &cpu, &sep); |
| 66 | + |
| 67 | + if (n <= 0) |
| 68 | + break; |
| 69 | + |
| 70 | + /* EOF == EOLN */ |
| 71 | + if (n == 1) |
| 72 | + sep = '\n'; |
| 73 | + |
| 74 | + /* Was the previous CPU a range? */ |
| 75 | + if (prev >= 0) { |
| 76 | + nr_cpus += cpu - prev + 1; |
| 77 | + prev = -1; |
| 78 | + } else if (sep == '-') |
| 79 | + prev = cpu; |
| 80 | + else |
| 81 | + nr_cpus++; |
| 82 | + |
| 83 | + if (sep == '\n') |
| 84 | + break; |
| 85 | + } |
| 86 | + fclose(file); |
| 87 | + return nr_cpus; |
| 88 | +} |
| 89 | + |
| 90 | +int __get_nprocs () |
| 91 | +{ |
| 92 | + long ret; |
| 93 | + static int cached = -1; |
| 94 | + |
| 95 | + ret = cached; |
| 96 | + if (ret < 0) |
| 97 | + { |
| 98 | + ret = __get_sysfs_cpus("/sys/devices/system/cpu/online"); |
| 99 | + cached = ret; |
| 100 | + } |
| 101 | + return ret; |
| 102 | +} |
| 103 | + |
| 104 | +int __get_nprocs_conf () |
| 105 | +{ |
| 106 | + long ret; |
| 107 | + static int cached = -1; |
| 108 | + |
| 109 | + ret = cached; |
| 110 | + if (ret < 0) |
| 111 | + { |
| 112 | + ret = __get_sysfs_cpus("/sys/devices/system/cpu/possible"); |
| 113 | + cached = ret; |
| 114 | + } |
| 115 | + return ret; |
| 116 | +} |
| 117 | +#endif |
| 118 | +#endif |
| 119 | + |
| 120 | /* Prepares the crash memory headers and stores in supplied buffer. */ |
| 121 | int FUNC(struct kexec_info *info, |
| 122 | struct crash_elf_info *elf_info, |
| 123 | @@ -46,7 +134,11 @@ int FUNC(struct kexec_info *info, |
| 124 | if (xen_present()) |
| 125 | nr_cpus = xen_get_nr_phys_cpus(); |
| 126 | else |
| 127 | +#ifndef __KLIBC__ |
| 128 | nr_cpus = sysconf(_SC_NPROCESSORS_CONF); |
| 129 | +#else |
| 130 | + nr_cpus = __get_nprocs_conf(); |
| 131 | +#endif |
| 132 | |
| 133 | if (nr_cpus < 0) { |
| 134 | return -1; |