motorhead/qemu
1
0
Fork 0
mirror of https://github.com/Motorhead1991/qemu.git synced 2025-08-03 07:43:54 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions

tests/tcg/s390x: Test modifying code using the MVC instruction

Browse source 
Add a small test to prevent regressions.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-ID: <20250128001338.11474-2-iii@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
This commit is contained in:
Ilya Leoshkevich 2025-01-28 01:12:43 +01:00 • committed by Thomas Huth
parent e43ced8be1
commit b497b0376c
2 changed files with 83 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

1
tests/tcg/s390x/Makefile.softmmu-target
View file

@ -42,6 +42,7 @@ $(ASM_TESTS): LDFLAGS += -Wl,-T$(LINK_SCRIPT) -Wl,--build-id=none
$(ASM_TESTS): $(LINK_SCRIPT)
TESTS += $(ASM_TESTS)
MULTIARCH_TESTS += mvc-smc
S390X_MULTIARCH_RUNTIME_OBJS = head64.o console.o $(MINILIB_OBJS)
$(MULTIARCH_TESTS): $(S390X_MULTIARCH_RUNTIME_OBJS)
$(MULTIARCH_TESTS): LDFLAGS += $(S390X_MULTIARCH_RUNTIME_OBJS)

82
tests/tcg/s390x/mvc-smc.c Normal file
View file

@ -0,0 +1,82 @@
/*
* Test modifying code using the MVC instruction.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include <minilib.h>
#define PAGE_SIZE 4096
#define BR_14_SIZE 2
#define RWX_OFFSET 2
static unsigned char rw[PAGE_SIZE + BR_14_SIZE];
static unsigned char rwx[RWX_OFFSET + sizeof(rw)]
__attribute__((aligned(PAGE_SIZE)));
typedef unsigned long (*function_t)(unsigned long);
static int emit_function(unsigned char *p, int n)
{
int i = 0, val = 0;
while (i < n - 2) {
/* aghi %r2,1 */
p[i++] = 0xa7;
p[i++] = 0x2b;
p[i++] = 0x00;
p[i++] = 0x01;
val++;
}
/* br %r14 */
p[i++] = 0x07;
p[i++] = 0xfe;
return val;
}
static void memcpy_mvc(void *dest, void *src, unsigned long n)
{
while (n >= 256) {
asm("mvc 0(256,%[dest]),0(%[src])"
:
: [dest] "a" (dest)
, [src] "a" (src)
: "memory");
dest += 256;
src += 256;
n -= 256;
}
asm("exrl %[n],0f\n"
"j 1f\n"
"0: mvc 0(1,%[dest]),0(%[src])\n"
"1:"
:
: [dest] "a" (dest)
, [src] "a" (src)
, [n] "a" (n)
: "memory");
}
int main(void)
{
int expected, size;
/* Create a TB. */
size = sizeof(rwx) - RWX_OFFSET - 4;
expected = emit_function(rwx + RWX_OFFSET, size);
if (((function_t)(rwx + RWX_OFFSET))(0) != expected) {
return 1;
}
/* Overwrite the TB. */
size += 4;
expected = emit_function(rw, size);
memcpy_mvc(rwx + RWX_OFFSET, rw, size);
if (((function_t)(rwx + RWX_OFFSET))(0) != expected) {
return 2;
}
return 0;
}