The branch stable/13 has been updated by kib:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=05c462f16a61ee46730d9d979ea958ff49f67af3

commit 05c462f16a61ee46730d9d979ea958ff49f67af3
Author:     Konstantin Belousov <[email protected]>
AuthorDate: 2022-09-12 19:32:02 +0000
Commit:     Konstantin Belousov <[email protected]>
CommitDate: 2022-09-30 00:29:09 +0000

    Add AT_USRSTACK{BASE, LIM} AT vectors, and ELF_BSDF_VMNOOVERCOMMIT flag
    
    (cherry picked from commit ff41239f587f2c2850c10639bd0ab8b5422b33fa)
---
 sys/kern/imgact_elf.c | 17 ++++++++++++++---
 sys/sys/elf_common.h  |  5 ++++-
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/sys/kern/imgact_elf.c b/sys/kern/imgact_elf.c
index 34cfef0d7cd9..3308a27953a8 100644
--- a/sys/kern/imgact_elf.c
+++ b/sys/kern/imgact_elf.c
@@ -1439,11 +1439,15 @@ __elfN(freebsd_copyout_auxargs)(struct image_params 
*imgp, uintptr_t base)
 {
        Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs;
        Elf_Auxinfo *argarray, *pos;
-       int error;
+       struct vmspace *vmspace;
+       rlim_t stacksz;
+       int error, bsdflags, oc;
 
        argarray = pos = malloc(AT_COUNT * sizeof(*pos), M_TEMP,
            M_WAITOK | M_ZERO);
 
+       vmspace = imgp->proc->p_vmspace;
+
        if (args->execfd != -1)
                AUXARGS_ENTRY(pos, AT_EXECFD, args->execfd);
        AUXARGS_ENTRY(pos, AT_PHDR, args->phdr);
@@ -1478,8 +1482,12 @@ __elfN(freebsd_copyout_auxargs)(struct image_params 
*imgp, uintptr_t base)
                AUXARGS_ENTRY(pos, AT_HWCAP, *imgp->sysent->sv_hwcap);
        if (imgp->sysent->sv_hwcap2 != NULL)
                AUXARGS_ENTRY(pos, AT_HWCAP2, *imgp->sysent->sv_hwcap2);
-       AUXARGS_ENTRY(pos, AT_BSDFLAGS, __elfN(sigfastblock) ?
-           ELF_BSDF_SIGFASTBLK : 0);
+       bsdflags = 0;
+       bsdflags |= __elfN(sigfastblock) ? ELF_BSDF_SIGFASTBLK : 0;
+       oc = atomic_load_int(&vm_overcommit);
+       bsdflags |= (oc & (SWAP_RESERVE_FORCE_ON | SWAP_RESERVE_RLIMIT_ON)) !=
+           0 ? ELF_BSDF_VMNOOVERCOMMIT : 0;
+       AUXARGS_ENTRY(pos, AT_BSDFLAGS, bsdflags);
        AUXARGS_ENTRY(pos, AT_ARGC, imgp->args->argc);
        AUXARGS_ENTRY_PTR(pos, AT_ARGV, imgp->argv);
        AUXARGS_ENTRY(pos, AT_ENVC, imgp->args->envc);
@@ -1489,6 +1497,9 @@ __elfN(freebsd_copyout_auxargs)(struct image_params 
*imgp, uintptr_t base)
                AUXARGS_ENTRY(pos, AT_FXRNG, imgp->sysent->sv_fxrng_gen_base);
        if (imgp->sysent->sv_vdso_base != 0 && __elfN(vdso) != 0)
                AUXARGS_ENTRY(pos, AT_KPRELOAD, imgp->sysent->sv_vdso_base);
+       AUXARGS_ENTRY(pos, AT_USRSTACKBASE, round_page(vmspace->vm_stacktop));
+       stacksz = imgp->proc->p_limit->pl_rlimit[RLIMIT_STACK].rlim_cur;
+       AUXARGS_ENTRY(pos, AT_USRSTACKLIM, stacksz);
        AUXARGS_ENTRY(pos, AT_NULL, 0);
 
        free(imgp->auxargs, M_TEMP);
diff --git a/sys/sys/elf_common.h b/sys/sys/elf_common.h
index 5b7a290fd761..884b8bb18d4f 100644
--- a/sys/sys/elf_common.h
+++ b/sys/sys/elf_common.h
@@ -985,8 +985,10 @@ typedef struct {
 #define        AT_PS_STRINGS   32      /* struct ps_strings */
 #define        AT_FXRNG        33      /* Pointer to root RNG seed version. */
 #define        AT_KPRELOAD     34      /* Base of vdso, preloaded by rtld */
+#define        AT_USRSTACKBASE 35      /* Top of user stack */
+#define        AT_USRSTACKLIM  36      /* Grow limit of user stack */
 
-#define        AT_COUNT        35      /* Count of defined aux entry types. */
+#define        AT_COUNT        37      /* Count of defined aux entry types. */
 
 /*
  * Relocation types.
@@ -1504,5 +1506,6 @@ typedef struct {
 #define        R_X86_64_REX_GOTPCRELX  42
 
 #define        ELF_BSDF_SIGFASTBLK     0x0001  /* Kernel supports fast 
sigblock */
+#define        ELF_BSDF_VMNOOVERCOMMIT 0x0002
 
 #endif /* !_SYS_ELF_COMMON_H_ */

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