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Update following the removal of bootstrap.h in favor of libukpm #101

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Update following the removal of bootstrap.h in favor of libukpm #101

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4449b00
Updates for libukpaging
michpappas Dec 17, 2025
442fadd
Remove `bootstrap.h`, obsoleted in favor of `libukpm`
mogasergiu Feb 5, 2026
eb538b7
Fix return value and invalid free upon nonexisting executable
mogasergiu Feb 5, 2026
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1 change: 0 additions & 1 deletion elf_ctx.c
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Original file line number Diff line number Diff line change
Expand Up @@ -48,7 +48,6 @@

#include <limits.h>
#include <string.h>
#include <uk/plat/bootstrap.h>
#include <uk/assert.h>
#include <uk/print.h>
#include <uk/essentials.h>
Expand Down
58 changes: 32 additions & 26 deletions elf_load.c
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Original file line number Diff line number Diff line change
Expand Up @@ -63,6 +63,7 @@
#include <uk/arch/limits.h>
#endif /* CONFIG_LIBUKVMEM */
#include <sys/mman.h>
#include <uk/paging.h>

#include "libelf_helper.h"
#include "elf_prog.h"
Expand Down Expand Up @@ -229,7 +230,7 @@ static int elf_load_parse(struct elf_prog *elf_prog, Elf *elf)

elf_prog->phdr.num = ehdr.e_phnum;
elf_prog->phdr.entsize = ehdr.e_phentsize;
elf_prog->valen = PAGE_ALIGN_UP(elf_prog->upperl);
elf_prog->valen = UK_PAGING_PAGE_ALIGN_UP(elf_prog->upperl);
return 0;

err_out:
Expand Down Expand Up @@ -273,7 +274,7 @@ static int elf_load_imgcpy(struct elf_prog *elf_prog, Elf *elf,
GElf_Phdr phdr;
int ret;

UK_ASSERT(elf_prog->align && PAGE_ALIGNED(elf_prog->align));
UK_ASSERT(elf_prog->align && UK_PAGING_PAGE_ALIGNED(elf_prog->align));

if (unlikely(gelf_getehdr(elf, &ehdr) == NULL)) {
elferr_err("%s: Failed to get executable header",
Expand Down Expand Up @@ -331,7 +332,7 @@ static int elf_load_imgcpy(struct elf_prog *elf_prog, Elf *elf,
/* Compute the area that needs to be zeroed */
vastart = vaend;
vaend = vastart + (phdr.p_memsz - phdr.p_filesz);
vaend = PAGE_ALIGN_UP(vaend);
vaend = UK_PAGING_PAGE_ALIGN_UP(vaend);
uk_pr_debug("%s: Zeroing 0x%"PRIx64" - 0x%"PRIx64"\n",
elf_prog->name,
(uint64_t) (vastart),
Expand Down Expand Up @@ -367,28 +368,29 @@ static int elf_load_mmap_filesz_memsz_diff(struct elf_prog *elf_prog,
/* From the last byte contained in filesz to the last
* byte contained in memsz, we can either have:
* 1. a page alignment adjustment, where the end
* address is just PAGE_ALIGN_UP(paddr + filesz), which
* means that our initial call to mmap already read in
* address is just UK_PAGING_PAGE_ALIGN_UP(paddr + filesz),
* which means that our initial call to mmap already read in
* a page for us whose remaining bytes we memset without
* generating a page fault, because
* vaend - vastart < PAGE_SIZE
* vaend - vastart < UK_PAGING_PAGE_SIZE
* ...
*/
memset((void *)vastart, 0, PAGE_ALIGN_UP(vastart) - vastart);
memset((void *)vastart, 0,
UK_PAGING_PAGE_ALIGN_UP(vastart) - vastart);
}

if (vaend == PAGE_ALIGN_UP(vastart))
if (vaend == UK_PAGING_PAGE_ALIGN_UP(vastart))
return 0;

/*
* ...
* 2. vaend - vastart >= PAGE_SIZE, which can happen if
* 2. vaend - vastart >= UK_PAGING_PAGE_SIZE, which can happen if
* this segment contains a NOBITS section, such as .bss.
* If that is the case, then simply anonymously map this
* remaining area so that we don't waste time memsetting
* it (.bss is quite large).
*/
vastart = PAGE_ALIGN_UP(vastart);
vastart = UK_PAGING_PAGE_ALIGN_UP(vastart);
vastart = (uintptr_t)mmap((void *)vastart, vaend - vastart,
get_phdr_mmap_prot(phdr),
MAP_PRIVATE | MAP_FIXED | MAP_ANONYMOUS,
Expand Down Expand Up @@ -470,7 +472,8 @@ static int do_elf_load_fdphdr_0(struct elf_prog *elf_prog,

/* mmap anonymously what we are left if memsz > filesz */
vastart += phdr->p_filesz;
vaend = PAGE_ALIGN_UP(vastart + (phdr->p_memsz - phdr->p_filesz));
vaend = UK_PAGING_PAGE_ALIGN_UP(vastart + (phdr->p_memsz -
phdr->p_filesz));
if (vaend > vastart) {
rc = elf_load_mmap_filesz_memsz_diff(elf_prog, phdr,
vastart, vaend);
Expand Down Expand Up @@ -504,10 +507,11 @@ static int do_elf_load_fdphdr_not0(struct elf_prog *elf_prog,
* Therefore, taking care of the address misalignment will also take
* care of the file misalignment.
*/
delta_p_offset = phdr->p_vaddr - PAGE_ALIGN_DOWN(phdr->p_vaddr);
delta_p_offset = phdr->p_vaddr -
UK_PAGING_PAGE_ALIGN_DOWN(phdr->p_vaddr);

addr = (void *)PAGE_ALIGN_DOWN((phdr->p_vaddr +
(uintptr_t)elf_prog->vabase));
addr = (void *)UK_PAGING_PAGE_ALIGN_DOWN((phdr->p_vaddr +
(uintptr_t)elf_prog->vabase));

uk_pr_debug("%s: Memory mapping 0x%"PRIx64" - 0x%"PRIx64" to 0x%"PRIx64" - 0x%"PRIx64"\n",
elf_prog->name,
Expand All @@ -531,11 +535,11 @@ static int do_elf_load_fdphdr_not0(struct elf_prog *elf_prog,
}

vastart += phdr->p_filesz + delta_p_offset;
vaend = PAGE_ALIGN_UP(vastart +
vaend = UK_PAGING_PAGE_ALIGN_UP(vastart +
(phdr->p_memsz - phdr->p_filesz));
} else {
vastart = (uintptr_t)addr;
vaend = PAGE_ALIGN_UP(vastart + phdr->p_memsz +
vaend = UK_PAGING_PAGE_ALIGN_UP(vastart + phdr->p_memsz +
delta_p_offset);
}

Expand Down Expand Up @@ -618,7 +622,7 @@ static int elf_load_fdphdr(struct elf_prog *elf_prog, GElf_Phdr *phdr, int fd)
/* Compute the area that needs to be zeroed */
vastart = vaend;
vaend = vastart + (phdr->p_memsz - phdr->p_filesz);
vaend = PAGE_ALIGN_UP(vaend);
vaend = UK_PAGING_PAGE_ALIGN_UP(vaend);
uk_pr_debug("%s: Zeroing 0x%"PRIx64" - 0x%"PRIx64"\n",
elf_prog->name,
(uint64_t)(vastart),
Expand All @@ -636,7 +640,7 @@ static int elf_load_fd(struct elf_prog *elf_prog, Elf *elf, int fd)
GElf_Phdr phdr;
int ret = -1;

UK_ASSERT(elf_prog->align && PAGE_ALIGNED(elf_prog->align));
UK_ASSERT(elf_prog->align && UK_PAGING_PAGE_ALIGNED(elf_prog->align));

if (unlikely(gelf_getehdr(elf, &ehdr) == NULL)) {
elferr_err("%s: Failed to get executable header",
Expand Down Expand Up @@ -783,8 +787,8 @@ static int elf_load_ptprotect(struct elf_prog *elf_prog, Elf *elf)

vastart = phdr.p_vaddr + (uintptr_t)elf_prog->vabase;
vaend = vastart + phdr.p_memsz;
vastart = PAGE_ALIGN_DOWN(vastart);
vaend = PAGE_ALIGN_UP(vaend);
vastart = UK_PAGING_PAGE_ALIGN_DOWN(vastart);
vaend = UK_PAGING_PAGE_ALIGN_UP(vaend);
valen = vaend - vastart;
uk_pr_debug("%s: Protecting 0x%"PRIx64" - 0x%"PRIx64": %c%c%c\n",
elf_prog->name,
Expand All @@ -795,11 +799,11 @@ static int elf_load_ptprotect(struct elf_prog *elf_prog, Elf *elf)
phdr.p_flags & PF_X ? 'X' : '-');
ret = uk_vma_set_attr(vas, vastart, valen,
((phdr.p_flags & PF_R) ?
PAGE_ATTR_PROT_READ : 0x0) |
UK_PAGING_PAGE_ATTR_PROT_READ : 0x0) |
((phdr.p_flags & PF_W) ?
PAGE_ATTR_PROT_WRITE : 0x0) |
UK_PAGING_PAGE_ATTR_PROT_WRITE : 0x0) |
((phdr.p_flags & PF_X) ?
PAGE_ATTR_PROT_EXEC : 0x0),
UK_PAGING_PAGE_ATTR_PROT_EXEC : 0x0),
0);
if (ret < 0)
uk_pr_err("%s: Failed to set protection bits: %d. Program execution may fail or might be unsafe.\n",
Expand All @@ -825,13 +829,15 @@ static void elf_unload_ptunprotect(struct elf_prog *elf_prog)

vastart = (uintptr_t) elf_prog->vabase;
vaend = vastart + (uintptr_t) elf_prog->valen;
vastart = PAGE_ALIGN_DOWN(vastart);
vaend = PAGE_ALIGN_UP(vaend);
vastart = UK_PAGING_PAGE_ALIGN_DOWN(vastart);
vaend = UK_PAGING_PAGE_ALIGN_UP(vaend);
valen = vaend - vastart;
uk_pr_debug("%s: Restore RW- protection: 0x%"PRIx64" - 0x%"PRIx64"\n",
elf_prog->name, (uint64_t) vastart, (uint64_t) vaend);
ret = uk_vma_set_attr(vas, vastart, valen,
(PAGE_ATTR_PROT_READ | PAGE_ATTR_PROT_WRITE), 0);
(UK_PAGING_PAGE_ATTR_PROT_READ |
UK_PAGING_PAGE_ATTR_PROT_WRITE),
0);
if (unlikely(ret < 0))
uk_pr_err("%s: Failed to restore protection bits: %d.\n",
elf_prog->name, ret);
Expand Down
7 changes: 4 additions & 3 deletions main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -267,9 +267,10 @@ int main(int argc, const char *argv[])
if (PTR2ERR(realpath) == -EINVAL) {
realpath = NULL;
} else if (PTRISERR(realpath) && PTR2ERR(realpath) != -EINVAL) {
uk_pr_err("%s: Failed to find executable in environment ($PATH): %s (%d)",
uk_pr_err("%s: Failed to find executable in environment ($PATH): %s (%d)\n",
progname, strerror(-PTR2ERR(realpath)),
PTR2ERR(realpath));
ret = PTR2ERR(realpath);
goto out;
}
}
Expand Down Expand Up @@ -425,10 +426,10 @@ int main(int argc, const char *argv[])
out:
#if CONFIG_APPELFLOADER_VFSEXEC
#if CONFIG_APPELFLOADER_VFSEXEC_ENVPATH
if (realpath)
if (realpath && !PTRISERR(realpath))
free(realpath);
#endif /* CONFIG_APPELFLOADER_VFSEXEC_ENVPATH */
if (progname_conv)
if (progname_conv && !PTRISERR(progname_conv))
free(progname_conv);
#endif /* CONFIG_APPELFLOADER_VFSEXEC */
return ret;
Expand Down