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S390: Always use svc 0

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On s390x syscalls are triggered by svc instruction. One can
pass the syscall number encoded in the instruction "svc 123"
or by storing it in r1:
lghi r1,123
svc 0

If the syscall number is encoded in the instruction, this can
cause broken syscall restarts.  Therefore this patch is now just
passing the syscall number in r1.

See also kernel-commit:
"s390/signal: switch to using vdso for sigreturn and syscall restart"
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/arch/s390/[%e2%80%a6]call.c?h=v6.0-rc1&id=df29a7440c4b5c65765c8f60396b3b13063e24e9

As information, the "svc 0" feature was introduced in kernel 2.5.62:
commit b5aad611393ef2e132e3648fa4c6e56a9cfa8708
This commit is contained in:
Stefan Liebler 2022-08-25 12:17:48 +02:00
parent 1d495912a7
commit e57d8fc97b
13 changed files with 46 additions and 66 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

14
sysdeps/unix/sysv/linux/s390/s390-32/clone.S
View file

@ -30,9 +30,10 @@
.text .text
ENTRY(__clone) ENTRY(__clone)
st %r6,24(%r15) /* store %r6 to save area */ stm %r6,%r7,24(%r15) /* Save registers. */
cfi_offset (%r7, -68)
cfi_offset (%r6, -72) cfi_offset (%r6, -72)
ltr %r1,%r2 /* check fn and move to %r1 */ ltr %r7,%r2 /* check fn and move to %r7 */
jz error /* no NULL function pointers */ jz error /* no NULL function pointers */
lhi %r0,-8 /* Align the child_stack to a ... */ lhi %r0,-8 /* Align the child_stack to a ... */
nr %r3,%r0 /* double word boundary and ... */ nr %r3,%r0 /* double word boundary and ... */
@ -43,10 +44,11 @@ ENTRY(__clone)
lr %r4,%r6 /* move parent_tid to %r4 */ lr %r4,%r6 /* move parent_tid to %r4 */
l %r5,100(%r15) /* load child_tid from stack */ l %r5,100(%r15) /* load child_tid from stack */
l %r6,96(%r15) /* load tls from stack */ l %r6,96(%r15) /* load tls from stack */
svc SYS_ify(clone) lhi %r1,SYS_ify(clone)
svc 0
ltr %r2,%r2 /* check return code */ ltr %r2,%r2 /* check return code */
jz thread_start jz thread_start
l %r6,24(%r15) /* restore %r6 */ lm %r6,%r7,24(%r15) /* Load registers. */
jm SYSCALL_ERROR_LABEL jm SYSCALL_ERROR_LABEL
br %r14 br %r14
error: error:
@ -58,11 +60,11 @@ thread_start:
cfi_startproc cfi_startproc
/* Mark r14 as undefined in order to stop unwinding here! */ /* Mark r14 as undefined in order to stop unwinding here! */
cfi_undefined (r14) cfi_undefined (r14)
/* fn is in gpr 1, arg in gpr 0 */ /* fn is in gpr 7, arg in gpr 0 */
lr %r2,%r0 /* set first parameter to void *arg */ lr %r2,%r0 /* set first parameter to void *arg */
ahi %r15,-96 /* make room on the stack for the save area */ ahi %r15,-96 /* make room on the stack for the save area */
xc 0(4,%r15),0(%r15) xc 0(4,%r15),0(%r15)
basr %r14,%r1 /* jump to fn */ basr %r14,%r7 /* jump to fn */
DO_CALL (exit, 1) DO_CALL (exit, 1)
cfi_endproc cfi_endproc

8
sysdeps/unix/sysv/linux/s390/s390-32/getcontext.S
View file

@ -32,16 +32,18 @@
other than the PRESERVED state. */ other than the PRESERVED state. */
ENTRY(__getcontext) ENTRY(__getcontext)
lr %r1,%r2 lr %r0,%r2
/* rt_sigprocmask (SIG_BLOCK, NULL, &sc->sc_mask, sigsetsize). */ /* rt_sigprocmask (SIG_BLOCK, NULL, &sc->sc_mask, sigsetsize). */
la %r4,SC_MASK(%r2)
la %r2,SIG_BLOCK la %r2,SIG_BLOCK
slr %r3,%r3 slr %r3,%r3
la %r4,SC_MASK(%r1)
lhi %r5,_NSIG8 lhi %r5,_NSIG8
svc SYS_ify(rt_sigprocmask) lhi %r1,SYS_ify(rt_sigprocmask)
svc 0
/* Store fpu context. */ /* Store fpu context. */
lr %r1,%r0
stfpc SC_FPC(%r1) stfpc SC_FPC(%r1)
std %f0,SC_FPRS(%r1) std %f0,SC_FPRS(%r1)
std %f1,SC_FPRS+8(%r1) std %f1,SC_FPRS+8(%r1)

8
sysdeps/unix/sysv/linux/s390/s390-32/setcontext.S
View file

@ -30,16 +30,18 @@
other than the PRESERVED state. */ other than the PRESERVED state. */
ENTRY(__setcontext) ENTRY(__setcontext)
lr %r1,%r2 lr %r0,%r2
/* rt_sigprocmask (SIG_SETMASK, &sc->sc_mask, NULL, sigsetsize). */ /* rt_sigprocmask (SIG_SETMASK, &sc->sc_mask, NULL, sigsetsize). */
la %r3,SC_MASK(%r2)
la %r2,SIG_SETMASK la %r2,SIG_SETMASK
la %r3,SC_MASK(%r1)
slr %r4,%r4 slr %r4,%r4
lhi %r5,_NSIG8 lhi %r5,_NSIG8
svc SYS_ify(rt_sigprocmask) lhi %r1,SYS_ify(rt_sigprocmask)
svc 0
/* Load fpu context. */ /* Load fpu context. */
lr %r1,%r0
lfpc SC_FPC(%r1) lfpc SC_FPC(%r1)
ld %f0,SC_FPRS(%r1) ld %f0,SC_FPRS(%r1)
ld %f1,SC_FPRS+8(%r1) ld %f1,SC_FPRS+8(%r1)

3
sysdeps/unix/sysv/linux/s390/s390-32/swapcontext.S
View file

@ -73,7 +73,8 @@ ENTRY(__swapcontext)
la %r3,SC_MASK(%r5) la %r3,SC_MASK(%r5)
la %r4,SC_MASK(%r1) la %r4,SC_MASK(%r1)
lhi %r5,_NSIG8 lhi %r5,_NSIG8
svc SYS_ify(rt_sigprocmask) lhi %r1,SYS_ify(rt_sigprocmask)
svc 0
/* Load fpu context. */ /* Load fpu context. */
lr %r5,%r0 lr %r5,%r0

4
sysdeps/unix/sysv/linux/s390/s390-32/sysdep.h
View file

@ -155,12 +155,8 @@
lr %r0,%r7; \ lr %r0,%r7; \
l %r7,96(%r15); \ l %r7,96(%r15); \
.endif; \ .endif; \
.if SYS_ify (syscall) < 256; \
svc SYS_ify (syscall); \
.else; \
lhi %r1,SYS_ify (syscall); \ lhi %r1,SYS_ify (syscall); \
svc 0; \ svc 0; \
.endif; \
.if args > 5; \ .if args > 5; \
lr %r7,%r0; \ lr %r7,%r0; \
.endif .endif

3
sysdeps/unix/sysv/linux/s390/s390-32/vfork.S
View file

@ -28,7 +28,8 @@
ENTRY (__libc_vfork) ENTRY (__libc_vfork)
/* Do vfork system call. */ /* Do vfork system call. */
svc SYS_ify (vfork) lhi %r1,SYS_ify (vfork)
svc 0
/* Check for error. */ /* Check for error. */
lhi %r4,-4095 lhi %r4,-4095

14
sysdeps/unix/sysv/linux/s390/s390-64/clone.S
View file

@ -31,9 +31,10 @@
.text .text
ENTRY(__clone) ENTRY(__clone)
stg %r6,48(%r15) /* store %r6 to save area */ stmg %r6,%r7,48(%r15) /* Save registers. */
cfi_offset (%r7,-104)
cfi_offset (%r6,-112) cfi_offset (%r6,-112)
ltgr %r1,%r2 /* check fn and move to %r1 */ ltgr %r7,%r2 /* check fn and move to %r7 */
jz error /* no NULL function pointers */ jz error /* no NULL function pointers */
lghi %r0,-16 /* Align the child_stack to a ... */ lghi %r0,-16 /* Align the child_stack to a ... */
ngr %r3,%r0 /* double word boundary and ... */ ngr %r3,%r0 /* double word boundary and ... */
@ -44,10 +45,11 @@ ENTRY(__clone)
lgr %r4,%r6 /* move parent_tid to %r4 */ lgr %r4,%r6 /* move parent_tid to %r4 */
lg %r5,168(%r15) /* load child_tid from stack */ lg %r5,168(%r15) /* load child_tid from stack */
lg %r6,160(%r15) /* load tls from stack */ lg %r6,160(%r15) /* load tls from stack */
svc SYS_ify(clone) lghi %r1,SYS_ify (clone)
svc 0
ltgr %r2,%r2 /* check return code */ ltgr %r2,%r2 /* check return code */
jz thread_start jz thread_start
lg %r6,48(%r15) /* restore %r6 */ lmg %r6,%r7,48(%r15) /* Restore registers. */
jgm SYSCALL_ERROR_LABEL jgm SYSCALL_ERROR_LABEL
br %r14 br %r14
error: error:
@ -59,11 +61,11 @@ thread_start:
cfi_startproc cfi_startproc
/* Mark r14 as undefined in order to stop unwinding here! */ /* Mark r14 as undefined in order to stop unwinding here! */
cfi_undefined (r14) cfi_undefined (r14)
/* fn is in gpr 1, arg in gpr 0 */ /* fn is in gpr 7, arg in gpr 0 */
lgr %r2,%r0 /* set first parameter to void *arg */ lgr %r2,%r0 /* set first parameter to void *arg */
aghi %r15,-160 /* make room on the stack for the save area */ aghi %r15,-160 /* make room on the stack for the save area */
xc 0(8,%r15),0(%r15) xc 0(8,%r15),0(%r15)
basr %r14,%r1 /* jump to fn */ basr %r14,%r7 /* jump to fn */
DO_CALL (exit, 1) DO_CALL (exit, 1)
cfi_endproc cfi_endproc

8
sysdeps/unix/sysv/linux/s390/s390-64/getcontext.S
View file

@ -32,16 +32,18 @@
other than the PRESERVED state. */ other than the PRESERVED state. */
ENTRY(__getcontext) ENTRY(__getcontext)
lgr %r1,%r2 lgr %r0,%r2
/* rt_sigprocmask (SIG_BLOCK, NULL, &sc->sc_mask, sigsetsize). */ /* rt_sigprocmask (SIG_BLOCK, NULL, &sc->sc_mask, sigsetsize). */
la %r4,SC_MASK(%r2)
la %r2,SIG_BLOCK la %r2,SIG_BLOCK
slgr %r3,%r3 slgr %r3,%r3
la %r4,SC_MASK(%r1)
lghi %r5,_NSIG8 lghi %r5,_NSIG8
svc SYS_ify(rt_sigprocmask) lghi %r1,SYS_ify(rt_sigprocmask)
svc 0
/* Store fpu context. */ /* Store fpu context. */
lgr %r1,%r0
stfpc SC_FPC(%r1) stfpc SC_FPC(%r1)
std %f0,SC_FPRS(%r1) std %f0,SC_FPRS(%r1)
std %f1,SC_FPRS+8(%r1) std %f1,SC_FPRS+8(%r1)

8
sysdeps/unix/sysv/linux/s390/s390-64/setcontext.S
View file

@ -30,16 +30,18 @@
other than the PRESERVED state. */ other than the PRESERVED state. */
ENTRY(__setcontext) ENTRY(__setcontext)
lgr %r1,%r2 lgr %r0,%r2
/* sigprocmask (SIG_SETMASK, &sc->sc_mask, NULL). */ /* sigprocmask (SIG_SETMASK, &sc->sc_mask, NULL). */
la %r3,SC_MASK(%r2)
la %r2,SIG_SETMASK la %r2,SIG_SETMASK
la %r3,SC_MASK(%r1)
slgr %r4,%r4 slgr %r4,%r4
lghi %r5,_NSIG8 lghi %r5,_NSIG8
svc SYS_ify(rt_sigprocmask) lghi %r1,SYS_ify(rt_sigprocmask)
svc 0
/* Load fpu context. */ /* Load fpu context. */
lgr %r1,%r0
lfpc SC_FPC(%r1) lfpc SC_FPC(%r1)
ld %f0,SC_FPRS(%r1) ld %f0,SC_FPRS(%r1)
ld %f1,SC_FPRS+8(%r1) ld %f1,SC_FPRS+8(%r1)

3
sysdeps/unix/sysv/linux/s390/s390-64/swapcontext.S
View file

@ -73,7 +73,8 @@ ENTRY(__swapcontext)
la %r3,SC_MASK(%r5) la %r3,SC_MASK(%r5)
la %r4,SC_MASK(%r1) la %r4,SC_MASK(%r1)
lghi %r5,_NSIG8 lghi %r5,_NSIG8
svc SYS_ify(rt_sigprocmask) lghi %r1,SYS_ify(rt_sigprocmask)
svc 0
/* Load fpu context. */ /* Load fpu context. */
lgr %r5,%r0 lgr %r5,%r0

4
sysdeps/unix/sysv/linux/s390/s390-64/sysdep.h
View file

@ -153,12 +153,8 @@
lgr %r0,%r7; \ lgr %r0,%r7; \
lg %r7,160(%r15); \ lg %r7,160(%r15); \
.endif; \ .endif; \
.if SYS_ify (syscall) < 256; \
svc SYS_ify (syscall); \
.else; \
lghi %r1,SYS_ify (syscall); \ lghi %r1,SYS_ify (syscall); \
svc 0; \ svc 0; \
.endif; \
.if args > 5; \ .if args > 5; \
lgr %r7,%r0; \ lgr %r7,%r0; \
.endif .endif

3
sysdeps/unix/sysv/linux/s390/s390-64/vfork.S
View file

@ -28,7 +28,8 @@
ENTRY (__libc_vfork) ENTRY (__libc_vfork)
/* Do vfork system call. */ /* Do vfork system call. */
svc SYS_ify (vfork) lghi %r1,SYS_ify (vfork)
svc 0
/* Check for error. */ /* Check for error. */
lghi %r4,-4095 lghi %r4,-4095

32
sysdeps/unix/sysv/linux/s390/sysdep.h
View file

@ -21,32 +21,6 @@
#undef SYS_ify #undef SYS_ify
#define SYS_ify(syscall_name) __NR_##syscall_name #define SYS_ify(syscall_name) __NR_##syscall_name
#undef INTERNAL_SYSCALL_DIRECT
#define INTERNAL_SYSCALL_DIRECT(name, nr, args...) \
({ \
DECLARGS_##nr(args) \
register long int _ret __asm__("2"); \
__asm__ __volatile__ ( \
"svc %b1\n\t" \
: "=d" (_ret) \
: "i" (__NR_##name) ASMFMT_##nr \
: "memory" ); \
_ret; })
#undef INTERNAL_SYSCALL_SVC0
#define INTERNAL_SYSCALL_SVC0(name, nr, args...) \
({ \
DECLARGS_##nr(args) \
register unsigned long int _nr __asm__("1") = \
(unsigned long int)(__NR_##name); \
register long int _ret __asm__("2"); \
__asm__ __volatile__ ( \
"svc 0\n\t" \
: "=d" (_ret) \
: "d" (_nr) ASMFMT_##nr \
: "memory" ); \
_ret; })
#undef INTERNAL_SYSCALL_NCS #undef INTERNAL_SYSCALL_NCS
#define INTERNAL_SYSCALL_NCS(no, nr, args...) \ #define INTERNAL_SYSCALL_NCS(no, nr, args...) \
({ \ ({ \
@ -61,10 +35,8 @@
_ret; }) _ret; })
#undef INTERNAL_SYSCALL #undef INTERNAL_SYSCALL
#define INTERNAL_SYSCALL(name, nr, args...) \ #define INTERNAL_SYSCALL(name, nr, args...) \
(((__NR_##name) < 256) \ INTERNAL_SYSCALL_NCS(__NR_##name, nr, args)
? INTERNAL_SYSCALL_DIRECT(name, nr, args) \
: INTERNAL_SYSCALL_SVC0(name, nr, args))
#define DECLARGS_0() #define DECLARGS_0()
#define DECLARGS_1(arg1) \ #define DECLARGS_1(arg1) \