Hi,
While trying to understand the patch submitted at
https://lists.gnu.org/archive/html/bug-gnulib/2023-05/msg00048.html
I'm looking at three files:
* gnumach/x86_64/locore.S lines 512..519
ENTRY(alltraps)
pusha /* save the general registers */
trap_push_segs:
movq %ds,%rax /* and the segment registers */
pushq %rax
movq %es,%rax /* and the segment registers */
pushq %rax
PUSH_FSGS
By the definition of 'pusha' (line 42), this produces on the stack the values
of the
registers
unused
unused
es
ds
r15
r14
r13
r12
r11
r10
r9
r8
rdi
rsi
rbp
unused
rbx
rdx
rcx
rax
* glibc/sysdeps/mach/hurd/x86_64/bits/sigcontext.h lines 57..79
* glibc/sysdeps/mach/hurd/x86/trampoline.c lines 239..247.
This code copies the values from the stack into a 'struct sigcontext'.
But here the order of the registers is
gs
fs
es
ds
r8
r9
r10
r11
r12
r13
r14
r15
rdi
rsi
rbp
unused
rbx
rdx
rcx
rax
This makes no sense to me. Either the fields of struct sigcontext should
be renamed
sc_r8 <--> sc_r15
sc_r9 <--> sc_r14
sc_r10 <--> sc_r13
sc_r11 <--> sc_r12
Or the pusha macro should be changed to
#define pusha pushq %rax ; pushq %rcx ; pushq %rdx ; pushq %rbx ; subq $8,%rsp
; pushq %rbp ; pushq %rsi ; pushq %rdi ; pushq %r15 ; pushq %r14 ; pushq %r13 ;
pushq %r12 ; pushq %r11 ; pushq %r10 ; pushq %r9 ; pushq %r8
and the popa macro accordingly.
Bruno
