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linux-user: Use walk_memory_regions for open_self_maps 
Replace the by-hand method of region identification with
the official user-exec interface.  Cross-check the region
provided to the callback with the interval tree from
read_self_maps().

Tested-by: Helge Deller <deller@gmx.de>
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
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@rth7680
rth7680 committed Sep 1, 2023
1 parent 79be812 commit 7b7a336
Showing 1 changed file with 114 additions and 76 deletions.
190 changes: 114 additions & 76 deletions linux-user/syscall.c
View file
Expand Up @@ -8095,12 +8095,66 @@ static int open_self_cmdline(CPUArchState *cpu_env, int fd)
return 0;
}

static void show_smaps(int fd, unsigned long size)
struct open_self_maps_data {
TaskState *ts;
IntervalTreeRoot *host_maps;
int fd;
bool smaps;
};

/*
* Subroutine to output one line of /proc/self/maps,
* or one region of /proc/self/smaps.
*/

#ifdef TARGET_HPPA
# define test_stack(S, E, L) (E == L)
#else
# define test_stack(S, E, L) (S == L)
#endif

static void open_self_maps_4(const struct open_self_maps_data *d,
const MapInfo *mi, abi_ptr start,
abi_ptr end, unsigned flags)
{
unsigned long page_size_kb = TARGET_PAGE_SIZE >> 10;
unsigned long size_kb = size >> 10;
const struct image_info *info = d->ts->info;
const char *path = mi->path;
uint64_t offset;
int fd = d->fd;
int count;

if (test_stack(start, end, info->stack_limit)) {
path = "[stack]";
}

/* Except null device (MAP_ANON), adjust offset for this fragment. */
offset = mi->offset;
if (mi->dev) {
uintptr_t hstart = (uintptr_t)g2h_untagged(start);
offset += hstart - mi->itree.start;
}

count = dprintf(fd, TARGET_ABI_FMT_ptr "-" TARGET_ABI_FMT_ptr
" %c%c%c%c %08" PRIx64 " %02x:%02x %"PRId64,
start, end,
(flags & PAGE_READ) ? 'r' : '-',
(flags & PAGE_WRITE_ORG) ? 'w' : '-',
(flags & PAGE_EXEC) ? 'x' : '-',
mi->is_priv ? 'p' : 's',
offset, major(mi->dev), minor(mi->dev),
(uint64_t)mi->inode);
if (path) {
dprintf(fd, "%*s%s\n", 73 - count, "", path);
} else {
dprintf(fd, "\n");
}

dprintf(fd, "Size: %lu kB\n"
if (d->smaps) {
unsigned long size = end - start;
unsigned long page_size_kb = TARGET_PAGE_SIZE >> 10;
unsigned long size_kb = size >> 10;

dprintf(fd, "Size: %lu kB\n"
"KernelPageSize: %lu kB\n"
"MMUPageSize: %lu kB\n"
"Rss: 0 kB\n"
Expand All @@ -8121,91 +8175,75 @@ static void show_smaps(int fd, unsigned long size)
"Swap: 0 kB\n"
"SwapPss: 0 kB\n"
"Locked: 0 kB\n"
"THPeligible: 0\n", size_kb, page_size_kb, page_size_kb);
"THPeligible: 0\n"
"VmFlags:%s%s%s%s%s%s%s%s\n",
size_kb, page_size_kb, page_size_kb,
(flags & PAGE_READ) ? " rd" : "",
(flags & PAGE_WRITE_ORG) ? " wr" : "",
(flags & PAGE_EXEC) ? " ex" : "",
mi->is_priv ? "" : " sh",
(flags & PAGE_READ) ? " mr" : "",
(flags & PAGE_WRITE_ORG) ? " mw" : "",
(flags & PAGE_EXEC) ? " me" : "",
mi->is_priv ? "" : " ms");
}
}

static int open_self_maps_1(CPUArchState *cpu_env, int fd, bool smaps)
/*
* Callback for walk_memory_regions, when read_self_maps() fails.
* Proceed without the benefit of host /proc/self/maps cross-check.
*/
static int open_self_maps_3(void *opaque, target_ulong guest_start,
target_ulong guest_end, unsigned long flags)
{
CPUState *cpu = env_cpu(cpu_env);
TaskState *ts = cpu->opaque;
IntervalTreeRoot *map_info = read_self_maps();
IntervalTreeNode *s;
int count;
static const MapInfo mi = { .is_priv = true };

for (s = interval_tree_iter_first(map_info, 0, -1); s;
s = interval_tree_iter_next(s, 0, -1)) {
MapInfo *e = container_of(s, MapInfo, itree);
open_self_maps_4(opaque, &mi, guest_start, guest_end, flags);
return 0;
}

if (h2g_valid(e->itree.start)) {
unsigned long min = e->itree.start;
unsigned long max = e->itree.last + 1;
int flags = page_get_flags(h2g(min));
const char *path;
/*
* Callback for walk_memory_regions, when read_self_maps() succeeds.
*/
static int open_self_maps_2(void *opaque, target_ulong guest_start,
target_ulong guest_end, unsigned long flags)
{
const struct open_self_maps_data *d = opaque;
uintptr_t host_start = (uintptr_t)g2h_untagged(guest_start);
uintptr_t host_last = (uintptr_t)g2h_untagged(guest_end - 1);

max = h2g_valid(max - 1) ?
max : (uintptr_t) g2h_untagged(GUEST_ADDR_MAX) + 1;
while (1) {
IntervalTreeNode *n =
interval_tree_iter_first(d->host_maps, host_start, host_start);
MapInfo *mi = container_of(n, MapInfo, itree);
uintptr_t this_hlast = MIN(host_last, n->last);
target_ulong this_gend = h2g(this_hlast) + 1;

if (!page_check_range(h2g(min), max - min, flags)) {
continue;
}
open_self_maps_4(d, mi, guest_start, this_gend, flags);

#ifdef TARGET_HPPA
if (h2g(max) == ts->info->stack_limit) {
#else
if (h2g(min) == ts->info->stack_limit) {
#endif
path = "[stack]";
} else {
path = e->path;
}

count = dprintf(fd, TARGET_ABI_FMT_ptr "-" TARGET_ABI_FMT_ptr
" %c%c%c%c %08" PRIx64 " %02x:%02x %"PRId64,
h2g(min), h2g(max - 1) + 1,
(flags & PAGE_READ) ? 'r' : '-',
(flags & PAGE_WRITE_ORG) ? 'w' : '-',
(flags & PAGE_EXEC) ? 'x' : '-',
e->is_priv ? 'p' : 's',
(uint64_t)e->offset,
major(e->dev), minor(e->dev),
(uint64_t)e->inode);
if (path) {
dprintf(fd, "%*s%s\n", 73 - count, "", path);
} else {
dprintf(fd, "\n");
}
if (smaps) {
show_smaps(fd, max - min);
dprintf(fd, "VmFlags:%s%s%s%s%s%s%s%s\n",
(flags & PAGE_READ) ? " rd" : "",
(flags & PAGE_WRITE_ORG) ? " wr" : "",
(flags & PAGE_EXEC) ? " ex" : "",
e->is_priv ? "" : " sh",
(flags & PAGE_READ) ? " mr" : "",
(flags & PAGE_WRITE_ORG) ? " mw" : "",
(flags & PAGE_EXEC) ? " me" : "",
e->is_priv ? "" : " ms");
}
if (this_hlast == host_last) {
return 0;
}
host_start = this_hlast + 1;
guest_start = h2g(host_start);
}
}

free_self_maps(map_info);
static int open_self_maps_1(CPUArchState *env, int fd, bool smaps)
{
struct open_self_maps_data d = {
.ts = env_cpu(env)->opaque,
.host_maps = read_self_maps(),
.fd = fd,
.smaps = smaps
};

#ifdef TARGET_VSYSCALL_PAGE
/*
* We only support execution from the vsyscall page.
* This is as if CONFIG_LEGACY_VSYSCALL_XONLY=y from v5.3.
*/
count = dprintf(fd, TARGET_FMT_lx "-" TARGET_FMT_lx
" --xp 00000000 00:00 0",
TARGET_VSYSCALL_PAGE, TARGET_VSYSCALL_PAGE + TARGET_PAGE_SIZE);
dprintf(fd, "%*s%s\n", 73 - count, "", "[vsyscall]");
if (smaps) {
show_smaps(fd, TARGET_PAGE_SIZE);
dprintf(fd, "VmFlags: ex\n");
if (d.host_maps) {
walk_memory_regions(&d, open_self_maps_2);
free_self_maps(d.host_maps);
} else {
walk_memory_regions(&d, open_self_maps_3);
}
#endif

return 0;
}

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