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linux-user: Pass image_range to probe_guest_base

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Pass a PGBRange structure instead of separate guest_loaddr
and guest_hiaddr parameters.  This allows NULL to indicate
that the image is relocatable, so that image_range->lo == 0
is a valid fixed setting.

Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/1890
Tested-by: Helge Deller <deller@gmx.de>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Helge Deller <deller@gmx.de>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson
2026-05-29 15:41:07 -07:00
parent 66259fc5a2
commit 3452cbd09f
3 changed files with 27 additions and 34 deletions
Download Patch File Download Diff File Expand all files Collapse all files

46
linux-user/elfload.c
View File

@@ -847,14 +847,13 @@ static bool pgb_try_mmap_set(const PGBAddrs *ga, uintptr_t base, uintptr_t brk)
/**
* pgb_addr_set:
* @ga: output set of guest addrs
* @guest_loaddr: guest image low address
* @guest_hiaddr: guest image high address
* @image_range: fixed guest image addresses
* @identity: create for identity mapping
*
* Fill in @ga with the image, COMMPAGE and NULL page.
*/
static bool pgb_addr_set(PGBAddrs *ga, abi_ulong guest_loaddr,
abi_ulong guest_hiaddr, bool try_identity)
static bool pgb_addr_set(PGBAddrs *ga, const PGBRange *image_range,
bool try_identity)
{
int n;
@@ -866,7 +865,7 @@ static bool pgb_addr_set(PGBAddrs *ga, abi_ulong guest_loaddr,
if (LO_COMMPAGE != -1 && LO_COMMPAGE < mmap_min_addr) {
return false;
}
if (guest_loaddr != 0 && guest_loaddr < mmap_min_addr) {
if (image_range && image_range->lo < mmap_min_addr) {
return false;
}
}
@@ -892,10 +891,8 @@ static bool pgb_addr_set(PGBAddrs *ga, abi_ulong guest_loaddr,
}
/* Add the guest image for ET_EXEC. */
if (guest_loaddr) {
ga->bounds[n].lo = guest_loaddr;
ga->bounds[n].hi = guest_hiaddr;
n++;
if (image_range) {
ga->bounds[n++] = *image_range;
}
}
@@ -928,8 +925,8 @@ static void pgb_fail_in_use(const char *image_name)
exit(EXIT_FAILURE);
}
static void pgb_fixed(const char *image_name, uintptr_t guest_loaddr,
uintptr_t guest_hiaddr, uintptr_t align)
static void pgb_fixed(const char *image_name, const PGBRange *image_range,
uintptr_t align)
{
PGBAddrs ga;
uintptr_t brk = (uintptr_t)sbrk(0);
@@ -941,7 +938,7 @@ static void pgb_fixed(const char *image_name, uintptr_t guest_loaddr,
exit(EXIT_FAILURE);
}
if (!pgb_addr_set(&ga, guest_loaddr, guest_hiaddr, !guest_base)
if (!pgb_addr_set(&ga, image_range, !guest_base)
|| !pgb_try_mmap_set(&ga, guest_base, brk)) {
pgb_fail_in_use(image_name);
}
@@ -1026,15 +1023,15 @@ static uintptr_t pgb_find_itree(const PGBAddrs *ga, IntervalTreeRoot *root,
return pgb_try_mmap_set(ga, base, brk) ? base : -1;
}
static void pgb_dynamic(const char *image_name, uintptr_t guest_loaddr,
uintptr_t guest_hiaddr, uintptr_t align)
static void pgb_dynamic(const char *image_name, const PGBRange *image_range,
uintptr_t align)
{
IntervalTreeRoot *root;
uintptr_t brk, ret;
PGBAddrs ga;
/* Try the identity map first. */
if (pgb_addr_set(&ga, guest_loaddr, guest_hiaddr, true)) {
if (pgb_addr_set(&ga, image_range, true)) {
brk = (uintptr_t)sbrk(0);
if (pgb_try_mmap_set(&ga, 0, brk)) {
guest_base = 0;
@@ -1046,7 +1043,7 @@ static void pgb_dynamic(const char *image_name, uintptr_t guest_loaddr,
* Rebuild the address set for non-identity map.
* This differs in the mapping of the guest NULL page.
*/
pgb_addr_set(&ga, guest_loaddr, guest_hiaddr, false);
pgb_addr_set(&ga, image_range, false);
root = read_self_maps();
@@ -1085,24 +1082,23 @@ static void pgb_dynamic(const char *image_name, uintptr_t guest_loaddr,
guest_base = ret;
}
void probe_guest_base(const char *image_name, abi_ulong guest_loaddr,
abi_ulong guest_hiaddr)
void probe_guest_base(const char *image_name, const PGBRange *image_range)
{
/* In order to use host shmat, we must be able to honor SHMLBA. */
uintptr_t align = MAX(SHMLBA, TARGET_PAGE_SIZE);
/* Sanity check the guest binary. */
if (reserved_va && guest_hiaddr > reserved_va) {
if (reserved_va && image_range && image_range->hi > reserved_va) {
error_report("%s: requires more than reserved virtual "
"address space (0x%" PRIx64 " > 0x%lx)",
image_name, (uint64_t)guest_hiaddr, reserved_va);
"address space (0x%" VADDR_PRIx " > 0x%lx)",
image_name, image_range->hi, reserved_va);
exit(EXIT_FAILURE);
}
if (have_guest_base) {
pgb_fixed(image_name, guest_loaddr, guest_hiaddr, align);
pgb_fixed(image_name, image_range, align);
} else {
pgb_dynamic(image_name, guest_loaddr, guest_hiaddr, align);
pgb_dynamic(image_name, image_range, align);
}
/* Reserve and initialize the commpage. */
@@ -1362,10 +1358,10 @@ static void load_elf_image(const char *image_name, const ImageSource *src,
* Make sure that the low address does not conflict with
* MMAP_MIN_ADDR or the QEMU application itself.
*/
probe_guest_base(image_name, range.lo, range.hi);
probe_guest_base(image_name, &range);
} else {
/* The binary is dynamic; we still need to select guest_base. */
probe_guest_base(image_name, 0, 0);
probe_guest_base(image_name, NULL);
/*
* Avoid collision with the loader by providing a different

2
linux-user/flatload.c
View File

@@ -261,7 +261,7 @@ static int load_flat_file(struct linux_binprm * bprm,
/*
* Allocate the address space.
*/
probe_guest_base(bprm->filename, 0, 0);
probe_guest_base(bprm->filename, NULL);
/*
* there are a couple of cases here, the separate code/data

13
linux-user/user-internals.h
View File

@@ -83,24 +83,21 @@ typedef struct PGBRange {
/**
* probe_guest_base:
* @image_name: the executable being loaded
* @loaddr: the lowest fixed address within the executable
* @hiaddr: the highest fixed address within the executable
* @image_range: the fixed addresses within the executable
*
* Creates the initial guest address space in the host memory space.
*
* If @loaddr == 0, then no address in the executable is fixed, i.e.
* it is fully relocatable. In that case @hiaddr is the size of the
* executable minus one.
* If @image_range is NULL, then no address in the executable is fixed,
* i.e. it is fully relocatable.
*
* This function will not return if a valid value for guest_base
* cannot be chosen. On return, the executable loader can expect
*
* target_mmap(loaddr, hiaddr - loaddr + 1, ...)
* target_mmap(i->lo, i->hi - i->lo + 1, ...)
*
* to succeed.
*/
void probe_guest_base(const char *image_name,
abi_ulong loaddr, abi_ulong hiaddr);
void probe_guest_base(const char *image_name, const PGBRange *image_range);
/* syscall.c */
int host_to_target_waitstatus(int status);