// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2019 ARM Limited */
#include <ctype.h>
#include <string.h>
#include "testcases.h"
struct _aarch64_ctx *get_header(struct _aarch64_ctx *head, uint32_t magic,
size_t resv_sz, size_t *offset)
{
size_t offs = 0;
struct _aarch64_ctx *found = NULL;
if (!head || resv_sz < HDR_SZ)
return found;
while (offs <= resv_sz - HDR_SZ &&
head->magic != magic && head->magic) {
offs += head->size;
head = GET_RESV_NEXT_HEAD(head);
}
if (head->magic == magic) {
found = head;
if (offset)
*offset = offs;
}
return found;
}
bool validate_extra_context(struct extra_context *extra, char **err,
void **extra_data, size_t *extra_size)
{
struct _aarch64_ctx *term;
if (!extra || !err)
return false;
fprintf(stderr, "Validating EXTRA...\n");
term = GET_RESV_NEXT_HEAD(&extra->head);
if (!term || term->magic || term->size) {
*err = "Missing terminator after EXTRA context";
return false;
}
if (extra->datap & 0x0fUL)
*err = "Extra DATAP misaligned";
else if (extra->size & 0x0fUL)
*err = "Extra SIZE misaligned";
else if (extra->datap != (uint64_t)term + 0x10UL)
*err = "Extra DATAP misplaced (not contiguous)";
if (*err)
return false;
*extra_data = (void *)extra->datap;
*extra_size = extra->size;
return true;
}
bool validate_sve_context(struct sve_context *sve, char **err)
{
/* Size will be rounded up to a multiple of 16 bytes */
size_t regs_size
= ((SVE_SIG_CONTEXT_SIZE(sve_vq_from_vl(sve->vl)) + 15) / 16) * 16;
if (!sve || !err)
return false;
/* Either a bare sve_context or a sve_context followed by regs data */
if ((sve->head.size != sizeof(struct sve_context)) &&
(sve->head.size != regs_size)) {
*err = "bad size for SVE context";
return false;
}
if (!sve_vl_valid(sve->vl)) {
*err = "SVE VL invalid";
return false;
}
return true;
}
bool validate_za_context(struct za_context *za, char **err)
{
/* Size will be rounded up to a multiple of 16 bytes */
size_t regs_size
= ((ZA_SIG_CONTEXT_SIZE(sve_vq_from_vl(za->vl)) + 15) / 16) * 16;
if (!za || !err)
return false;
/* Either a bare za_context or a za_context followed by regs data */
if ((za->head.size != sizeof(struct za_context)) &&
(za->head.size != regs_size)) {
*err = "bad size for ZA context";
return false;
}
if (!sve_vl_valid(za->vl)) {
*err = "SME VL in ZA context invalid";
return false;
}
return true;
}
bool validate_zt_context(struct zt_context *zt, char **err)
{
if (!zt || !err)
return false;
/* If the context is present there should be at least one register */
if (zt->nregs == 0) {
*err = "no registers";
return false;
}
/* Size should agree with the number of registers */
if (zt->head.size != ZT_SIG_CONTEXT_SIZE(zt->nregs)) {
*err = "register count does not match size";
return false;
}
return true;
}
bool validate_reserved(ucontext_t *uc, size_t resv_sz, char **err)
{
bool terminated = false;
size_t offs = 0;
int flags = 0;
int new_flags, i;
struct extra_context *extra = NULL;
struct sve_context *sve = NULL;
struct za_context *za = NULL;
struct zt_context *zt = NULL;
struct _aarch64_ctx *head =
(struct _aarch64_ctx *)uc->uc_mcontext.__reserved;
void *extra_data = NULL;
size_t extra_sz = 0;
char magic[4];
if (!err)
return false;
/* Walk till the end terminator verifying __reserved contents */
while (head && !terminated && offs < resv_sz) {
if ((uint64_t)head & 0x0fUL) {
*err = "Misaligned HEAD";
return false;
}
new_flags = 0;
switch (head->magic) {
case 0:
if (head->size) {
*err = "Bad size for terminator";
} else if (extra_data) {
/* End of main data, walking the extra data */
head = extra_data;
resv_sz = extra_sz;
offs = 0;
extra_data = NULL;
extra_sz = 0;
continue;
} else {
terminated = true;
}
break;
case FPSIMD_MAGIC:
if (flags & FPSIMD_CTX)
*err = "Multiple FPSIMD_MAGIC";
else if (head->size !=
sizeof(struct fpsimd_context))
*err = "Bad size for fpsimd_context";
new_flags |= FPSIMD_CTX;
break;
case ESR_MAGIC:
if (head->size != sizeof(struct esr_context))
*err = "Bad size for esr_context";
break;
case TPIDR2_MAGIC:
if (head->size != sizeof(struct tpidr2_context))
*err = "Bad size for tpidr2_context";
break;
case SVE_MAGIC:
if (flags & SVE_CTX)
*err = "Multiple SVE_MAGIC";
/* Size is validated in validate_sve_context() */
sve = (struct sve_context *)head;
new_flags |= SVE_CTX;
break;
case ZA_MAGIC:
if (flags & ZA_CTX)
*err = "Multiple ZA_MAGIC";
/* Size is validated in validate_za_context() */
za = (struct za_context *)head;
new_flags |= ZA_CTX;
break;
case ZT_MAGIC:
if (flags & ZT_CTX)
*err = "Multiple ZT_MAGIC";
/* Size is validated in validate_za_context() */
zt = (struct zt_context *)head;
new_flags |= ZT_CTX;
break;
case FPMR_MAGIC:
if (flags & FPMR_CTX)
*err = "Multiple FPMR_MAGIC";
else if (head->size !=
sizeof(struct fpmr_context))
*err = "Bad size for fpmr_context";
new_flags |= FPMR_CTX;
break;
case EXTRA_MAGIC:
if (flags & EXTRA_CTX)
*err = "Multiple EXTRA_MAGIC";
else if (head->size !=
sizeof(struct extra_context))
*err = "Bad size for extra_context";
new_flags |= EXTRA_CTX;
extra = (struct extra_context *)head;
break;
case KSFT_BAD_MAGIC:
/*
* This is a BAD magic header defined
* artificially by a testcase and surely
* unknown to the Kernel parse_user_sigframe().
* It MUST cause a Kernel induced SEGV
*/
*err = "BAD MAGIC !";
break;
default:
/*
* A still unknown Magic: potentially freshly added
* to the Kernel code and still unknown to the
* tests. Magic numbers are supposed to be allocated
* as somewhat meaningful ASCII strings so try to
* print as such as well as the raw number.
*/
memcpy(magic, &head->magic, sizeof(magic));
for (i = 0; i < sizeof(magic); i++)
if (!isalnum(magic[i]))
magic[i] = '?';
fprintf(stdout,
"SKIP Unknown MAGIC: 0x%X (%c%c%c%c) - Is KSFT arm64/signal up to date ?\n",
head->magic,
magic[3], magic[2], magic[1], magic[0]);
break;
}
if (*err)
return false;
offs += head->size;
if (resv_sz < offs + sizeof(*head)) {
*err = "HEAD Overrun";
return false;
}
if (new_flags & EXTRA_CTX)
if (!validate_extra_context(extra, err,
&extra_data, &extra_sz))
return false;
if (new_flags & SVE_CTX)
if (!validate_sve_context(sve, err))
return false;
if (new_flags & ZA_CTX)
if (!validate_za_context(za, err))
return false;
if (new_flags & ZT_CTX)
if (!validate_zt_context(zt, err))
return false;
flags |= new_flags;
head = GET_RESV_NEXT_HEAD(head);
}
if (terminated && !(flags & FPSIMD_CTX)) {
*err = "Missing FPSIMD";
return false;
}
if (terminated && (flags & ZT_CTX) && !(flags & ZA_CTX)) {
*err = "ZT context but no ZA context";
return false;
}
return true;
}
/*
* This function walks through the records inside the provided reserved area
* trying to find enough space to fit @need_sz bytes: if not enough space is
* available and an extra_context record is present, it throws away the
* extra_context record.
*
* It returns a pointer to a new header where it is possible to start storing
* our need_sz bytes.
*
* @shead: points to the start of reserved area
* @need_sz: needed bytes
* @resv_sz: reserved area size in bytes
* @offset: if not null, this will be filled with the offset of the return
* head pointer from @shead
*
* @return: pointer to a new head where to start storing need_sz bytes, or
* NULL if space could not be made available.
*/
struct _aarch64_ctx *get_starting_head(struct _aarch64_ctx *shead,
size_t need_sz, size_t resv_sz,
size_t *offset)
{
size_t offs = 0;
struct _aarch64_ctx *head;
head = get_terminator(shead, resv_sz, &offs);
/* not found a terminator...no need to update offset if any */
if (!head)
return head;
if (resv_sz - offs < need_sz) {
fprintf(stderr, "Low on space:%zd. Discarding extra_context.\n",
resv_sz - offs);
head = get_header(shead, EXTRA_MAGIC, resv_sz, &offs);
if (!head || resv_sz - offs < need_sz) {
fprintf(stderr,
"Failed to reclaim space on sigframe.\n");
return NULL;
}
}
fprintf(stderr, "Available space:%zd\n", resv_sz - offs);
if (offset)
*offset = offs;
return head;
}
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