linux_dsm_epyc7002/arch/um/os-Linux/sys-i386/tls.c
Paolo 'Blaisorblade' Giarrusso 3feb88562d [PATCH] uml: check for differences in host support
If running on a host not supporting TLS (for instance 2.4) we should report
that cleanly to the user, instead of printing not comprehensible "error 5" for
that.

Additionally, i386 and x86_64 support different ranges for
user_desc->entry_number, and we must account for that; we couldn't pass
ourselves -1 because we need to override previously existing TLS descriptors
which glibc has possibly set, so test at startup the range to use.

x86 and x86_64 existing ranges are hardcoded.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-03-31 12:18:52 -08:00

34 lines
813 B
C

#include <linux/unistd.h>
#include "sysdep/tls.h"
#include "user_util.h"
static _syscall1(int, get_thread_area, user_desc_t *, u_info);
/* Checks whether host supports TLS, and sets *tls_min according to the value
* valid on the host.
* i386 host have it == 6; x86_64 host have it == 12, for i386 emulation. */
void check_host_supports_tls(int *supports_tls, int *tls_min) {
/* Values for x86 and x86_64.*/
int val[] = {GDT_ENTRY_TLS_MIN_I386, GDT_ENTRY_TLS_MIN_X86_64};
int i;
for (i = 0; i < ARRAY_SIZE(val); i++) {
user_desc_t info;
info.entry_number = val[i];
if (get_thread_area(&info) == 0) {
*tls_min = val[i];
*supports_tls = 1;
return;
} else {
if (errno == EINVAL)
continue;
else if (errno == ENOSYS)
*supports_tls = 0;
return;
}
}
*supports_tls = 0;
}