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target/arm: Fix handling of setting SVE registers from gdb

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The code to handle setting SVE registers via the gdbstub is broken:
 * it sets each pair of elements in the zregs[].d[] array in the
   wrong order for the most common (little endian) case: the least
   significant 64-bit value comes first
 * it makes no attempt to handle target_endian()
 * it does a simple copy out of the (target endian) gdbstub buffer
   into the (host endan) zregs data structure, which is wrong on
   big endian hosts

Fix all these problems:
 * use ldq_p() to read from the gdbstub buffer
 * check target_big_endian() to see if we need to handle the
   128-bit values the opposite way around

Cc: qemu-stable@nongnu.org
Signed-off-by: Vacha Bhavsar <vacha.bhavsar@oss.qualcomm.com>
Message-id: 20250722173736.2332529-3-vacha.bhavsar@oss.qualcomm.com
[PMM: adjusted commit message, fixed spacing]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Vacha Bhavsar 2025-07-22 17:37:36 +00:00 • committed by Peter Maydell
parent 35cca0f95f
commit 97b3d732af
1 changed files with 12 additions and 5 deletions
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17
target/arm/gdbstub64.c
View file

@ -206,10 +206,17 @@ int aarch64_gdb_set_sve_reg(CPUState *cs, uint8_t *buf, int reg)
case 0 ... 31:
{
int vq, len = 0;
uint64_t *p = (uint64_t *) buf;
for (vq = 0; vq < cpu->sve_max_vq; vq++) {
env->vfp.zregs[reg].d[vq * 2 + 1] = *p++;
env->vfp.zregs[reg].d[vq * 2] = *p++;
if (target_big_endian()) {
env->vfp.zregs[reg].d[vq * 2 + 1] = ldq_p(buf);
buf += 8;
env->vfp.zregs[reg].d[vq * 2] = ldq_p(buf);
} else{
env->vfp.zregs[reg].d[vq * 2] = ldq_p(buf);
buf += 8;
env->vfp.zregs[reg].d[vq * 2 + 1] = ldq_p(buf);
}
buf += 8;
len += 16;
}
return len;
@ -224,9 +231,9 @@ int aarch64_gdb_set_sve_reg(CPUState *cs, uint8_t *buf, int reg)
{
int preg = reg - 34;
int vq, len = 0;
uint64_t *p = (uint64_t *) buf;
for (vq = 0; vq < cpu->sve_max_vq; vq = vq + 4) {
env->vfp.pregs[preg].p[vq / 4] = *p++;
env->vfp.pregs[preg].p[vq / 4] = ldq_p(buf);
buf += 8;
len += 8;
}
return len;