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From 1cfee75d9662c3382bb7cb8f1c952333837598ae Mon Sep 17 00:00:00 2001
From: Andrea Adami <andrea.adami@gmail.com>
Date: Wed, 18 Apr 2018 02:21:30 +0200
Subject: [PATCH] crashdump-elf.c: work around for _SC_NPROCESSORS_CONF
klibc sysconf lacks this so the implementation
of Linus Torvalds was taken (simplified):
https://sourceware.org/ml/libc-alpha/2011-06/msg00079.html
Have fun reding the thread!
Fix
crashdump-elf.c:117:21: error: '_SC_NPROCESSORS_CONF' undeclared
Upstream-Status: Inappropriate [klibc specific]
Signed-off-by: Andrea Adami <andrea.adami@gmail.com>
---
kexec/crashdump-elf.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 92 insertions(+)
diff --git a/kexec/crashdump-elf.c b/kexec/crashdump-elf.c
index b8bb686..7e6767c 100644
--- a/kexec/crashdump-elf.c
+++ b/kexec/crashdump-elf.c
@@ -25,6 +25,94 @@ do { \
} while(0)
#endif
+#ifdef __KLIBC__
+#ifndef KLIBC_SYSFS_CPU_H
+#define KLIBC_SYSFS_CPU_H
+
+
+static int __get_sysfs_cpus(const char *path);
+int __get_nprocs (void);
+int __get_nprocs_conf (void);
+
+
+
+static int __get_sysfs_cpus(const char *path)
+{
+ FILE *file;
+ int nr_cpus = 0;
+ int prev = -1;
+ char *p;
+ char line[10];
+
+
+ file = fopen(path, "r");
+ if (!file)
+ return -1;
+ for (;;) {
+ char sep;
+ int cpu;
+ int n;
+
+ /* int n = fscanf(file, "%u%c", &cpu, &sep); */
+ p = fgets(line, sizeof(line), file);
+ if (p == NULL)
+ return -1;
+ else
+ n = sscanf(line, "%u%c", &cpu, &sep);
+
+ if (n <= 0)
+ break;
+
+ /* EOF == EOLN */
+ if (n == 1)
+ sep = '\n';
+
+ /* Was the previous CPU a range? */
+ if (prev >= 0) {
+ nr_cpus += cpu - prev + 1;
+ prev = -1;
+ } else if (sep == '-')
+ prev = cpu;
+ else
+ nr_cpus++;
+
+ if (sep == '\n')
+ break;
+ }
+ fclose(file);
+ return nr_cpus;
+}
+
+int __get_nprocs ()
+{
+ long ret;
+ static int cached = -1;
+
+ ret = cached;
+ if (ret < 0)
+ {
+ ret = __get_sysfs_cpus("/sys/devices/system/cpu/online");
+ cached = ret;
+ }
+ return ret;
+}
+
+int __get_nprocs_conf ()
+{
+ long ret;
+ static int cached = -1;
+
+ ret = cached;
+ if (ret < 0)
+ {
+ ret = __get_sysfs_cpus("/sys/devices/system/cpu/possible");
+ cached = ret;
+ }
+ return ret;
+}
+#endif
+#endif
+
/* Prepares the crash memory headers and stores in supplied buffer. */
int FUNC(struct kexec_info *info,
struct crash_elf_info *elf_info,
@@ -46,7 +134,11 @@ int FUNC(struct kexec_info *info,
if (xen_present())
nr_cpus = xen_get_nr_phys_cpus();
else
+#ifndef __KLIBC__
nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+#else
+ nr_cpus = __get_nprocs_conf();
+#endif
if (nr_cpus < 0) {
return -1;
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