The branch main has been updated by kib:
URL:
https://cgit.FreeBSD.org/src/commit/?id=ff41239f587f2c2850c10639bd0ab8b5422b33fa
commit ff41239f587f2c2850c10639bd0ab8b5422b33fa
Author: Konstantin Belousov <k...@freebsd.org>
AuthorDate: 2022-09-12 19:32:02 +0000
Commit: Konstantin Belousov <k...@freebsd.org>
CommitDate: 2022-09-16 20:23:26 +0000
Add AT_USRSTACK{BASE, LIM} AT vectors, and ELF_BSDF_VMNOOVERCOMMIT flag
Reviewed by: brooks, imp (previous version)
Discussed with: markj
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
Differential revision: https://reviews.freebsd.org/D36540
---
sys/kern/imgact_elf.c | 14 +++++++++++---
sys/sys/elf_common.h | 5 ++++-
2 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/sys/kern/imgact_elf.c b/sys/kern/imgact_elf.c
index 6c36c880a2c0..1c13a9a7c737 100644
--- a/sys/kern/imgact_elf.c
+++ b/sys/kern/imgact_elf.c
@@ -1448,7 +1448,8 @@ __elfN(freebsd_copyout_auxargs)(struct image_params
*imgp, uintptr_t base)
Elf_Auxargs *args = (Elf_Auxargs *)imgp->auxargs;
Elf_Auxinfo *argarray, *pos;
struct vmspace *vmspace;
- int error;
+ rlim_t stacksz;
+ int error, bsdflags, oc;
argarray = pos = malloc(AT_COUNT * sizeof(*pos), M_TEMP,
M_WAITOK | M_ZERO);
@@ -1489,8 +1490,12 @@ __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);
@@ -1506,6 +1511,9 @@ __elfN(freebsd_copyout_auxargs)(struct image_params
*imgp, uintptr_t base)
AUXARGS_ENTRY(pos, AT_KPRELOAD,
vmspace->vm_shp_base + imgp->sysent->sv_vdso_offset);
}
+ 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 23440f535887..9366593b24bd 100644
--- a/sys/sys/elf_common.h
+++ b/sys/sys/elf_common.h
@@ -986,8 +986,10 @@ 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.
@@ -1501,5 +1503,6 @@ 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_ */
