svn commit: r345547 - head/sys/kern
Edward Tomasz Napierala
trasz at FreeBSD.org
Tue Mar 26 15:35:51 UTC 2019
Author: trasz
Date: Tue Mar 26 15:35:49 2019
New Revision: 345547
URL: https://svnweb.freebsd.org/changeset/base/345547
Log:
Factor out resource limit enforcement code in the ELF loader.
It makes the code slightly easier to follow, and might make
it easier to fix the resouce accounting to also account for
the interpreter.
The PROC_UNLOCK() is moved earlier - I don't see anything
it should protect; the lim_max() is a wrapper around lim_rlimit(),
and that, differently from lim_rlimit_proc(), doesn't require
the proc lock to be held.
Reviewed by: kib
MFC after: 2 weeks
Sponsored by: DARPA, AFRL
Differential Revision: https://reviews.freebsd.org/D19689
Modified:
head/sys/kern/imgact_elf.c
Modified: head/sys/kern/imgact_elf.c
==============================================================================
--- head/sys/kern/imgact_elf.c Tue Mar 26 13:53:33 2019 (r345546)
+++ head/sys/kern/imgact_elf.c Tue Mar 26 15:35:49 2019 (r345547)
@@ -812,6 +812,83 @@ __CONCAT(rnd_, __elfN(base))(vm_map_t map __unused, u_
return (res);
}
+static int
+__elfN(enforce_limits)(struct image_params *imgp, const Elf_Ehdr *hdr,
+ const Elf_Phdr *phdr, u_long et_dyn_addr)
+{
+ struct vmspace *vmspace;
+ const char *err_str;
+ u_long text_size, data_size, total_size, text_addr, data_addr;
+ u_long seg_size, seg_addr;
+ int i;
+
+ err_str = NULL;
+ text_size = data_size = total_size = text_addr = data_addr = 0;
+
+ for (i = 0; i < hdr->e_phnum; i++) {
+ if (phdr[i].p_type != PT_LOAD || phdr[i].p_memsz == 0)
+ continue;
+
+ seg_addr = trunc_page(phdr[i].p_vaddr + et_dyn_addr);
+ seg_size = round_page(phdr[i].p_memsz +
+ phdr[i].p_vaddr + et_dyn_addr - seg_addr);
+
+ /*
+ * Make the largest executable segment the official
+ * text segment and all others data.
+ *
+ * Note that obreak() assumes that data_addr + data_size == end
+ * of data load area, and the ELF file format expects segments
+ * to be sorted by address. If multiple data segments exist,
+ * the last one will be used.
+ */
+
+ if ((phdr[i].p_flags & PF_X) != 0 && text_size < seg_size) {
+ text_size = seg_size;
+ text_addr = seg_addr;
+ } else {
+ data_size = seg_size;
+ data_addr = seg_addr;
+ }
+ total_size += seg_size;
+ }
+
+ if (data_addr == 0 && data_size == 0) {
+ data_addr = text_addr;
+ data_size = text_size;
+ }
+
+ /*
+ * Check limits. It should be safe to check the
+ * limits after loading the segments since we do
+ * not actually fault in all the segments pages.
+ */
+ PROC_LOCK(imgp->proc);
+ if (data_size > lim_cur_proc(imgp->proc, RLIMIT_DATA))
+ err_str = "Data segment size exceeds process limit";
+ else if (text_size > maxtsiz)
+ err_str = "Text segment size exceeds system limit";
+ else if (total_size > lim_cur_proc(imgp->proc, RLIMIT_VMEM))
+ err_str = "Total segment size exceeds process limit";
+ else if (racct_set(imgp->proc, RACCT_DATA, data_size) != 0)
+ err_str = "Data segment size exceeds resource limit";
+ else if (racct_set(imgp->proc, RACCT_VMEM, total_size) != 0)
+ err_str = "Total segment size exceeds resource limit";
+ PROC_UNLOCK(imgp->proc);
+ if (err_str != NULL) {
+ uprintf("%s\n", err_str);
+ return (ENOMEM);
+ }
+
+ vmspace = imgp->proc->p_vmspace;
+ vmspace->vm_tsize = text_size >> PAGE_SHIFT;
+ vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr;
+ vmspace->vm_dsize = data_size >> PAGE_SHIFT;
+ vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr;
+
+ return (0);
+}
+
/*
* Impossible et_dyn_addr initial value indicating that the real base
* must be calculated later with some randomization applied.
@@ -827,13 +904,12 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *i
Elf_Auxargs *elf_auxargs;
struct vmspace *vmspace;
vm_map_t map;
- const char *err_str, *newinterp;
+ const char *newinterp;
char *interp, *interp_buf, *path;
Elf_Brandinfo *brand_info;
struct sysentvec *sv;
vm_prot_t prot;
- u_long text_size, data_size, total_size, text_addr, data_addr;
- u_long seg_size, seg_addr, addr, baddr, et_dyn_addr, entry, proghdr;
+ u_long addr, baddr, et_dyn_addr, entry, proghdr;
u_long maxalign, mapsz, maxv, maxv1;
uint32_t fctl0;
int32_t osrel;
@@ -872,10 +948,9 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *i
baddr = 0;
osrel = 0;
fctl0 = 0;
- text_size = data_size = total_size = text_addr = data_addr = 0;
entry = proghdr = 0;
interp_name_len = 0;
- err_str = newinterp = NULL;
+ newinterp = NULL;
interp = interp_buf = NULL;
td = curthread;
maxalign = PAGE_SIZE;
@@ -1064,30 +1139,6 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *i
<= phdr[i].p_filesz)
proghdr = phdr[i].p_vaddr + hdr->e_phoff +
et_dyn_addr;
-
- seg_addr = trunc_page(phdr[i].p_vaddr + et_dyn_addr);
- seg_size = round_page(phdr[i].p_memsz +
- phdr[i].p_vaddr + et_dyn_addr - seg_addr);
-
- /*
- * Make the largest executable segment the official
- * text segment and all others data.
- *
- * Note that obreak() assumes that data_addr +
- * data_size == end of data load area, and the ELF
- * file format expects segments to be sorted by
- * address. If multiple data segments exist, the
- * last one will be used.
- */
-
- if (phdr[i].p_flags & PF_X && text_size < seg_size) {
- text_size = seg_size;
- text_addr = seg_addr;
- } else {
- data_size = seg_size;
- data_addr = seg_addr;
- }
- total_size += seg_size;
break;
case PT_PHDR: /* Program header table info */
proghdr = phdr[i].p_vaddr + et_dyn_addr;
@@ -1096,41 +1147,12 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *i
break;
}
}
-
- if (data_addr == 0 && data_size == 0) {
- data_addr = text_addr;
- data_size = text_size;
- }
- entry = (u_long)hdr->e_entry + et_dyn_addr;
-
- /*
- * Check limits. It should be safe to check the
- * limits after loading the segments since we do
- * not actually fault in all the segments pages.
- */
- PROC_LOCK(imgp->proc);
- if (data_size > lim_cur_proc(imgp->proc, RLIMIT_DATA))
- err_str = "Data segment size exceeds process limit";
- else if (text_size > maxtsiz)
- err_str = "Text segment size exceeds system limit";
- else if (total_size > lim_cur_proc(imgp->proc, RLIMIT_VMEM))
- err_str = "Total segment size exceeds process limit";
- else if (racct_set(imgp->proc, RACCT_DATA, data_size) != 0)
- err_str = "Data segment size exceeds resource limit";
- else if (racct_set(imgp->proc, RACCT_VMEM, total_size) != 0)
- err_str = "Total segment size exceeds resource limit";
- if (err_str != NULL) {
- PROC_UNLOCK(imgp->proc);
- uprintf("%s\n", err_str);
- error = ENOMEM;
+ error = __elfN(enforce_limits)(imgp, hdr, phdr, et_dyn_addr);
+ if (error != 0)
goto ret;
- }
- vmspace->vm_tsize = text_size >> PAGE_SHIFT;
- vmspace->vm_taddr = (caddr_t)(uintptr_t)text_addr;
- vmspace->vm_dsize = data_size >> PAGE_SHIFT;
- vmspace->vm_daddr = (caddr_t)(uintptr_t)data_addr;
+ entry = (u_long)hdr->e_entry + et_dyn_addr;
/*
* We load the dynamic linker where a userland call
@@ -1148,7 +1170,6 @@ __CONCAT(exec_, __elfN(imgact))(struct image_params *i
} else {
map->anon_loc = addr;
}
- PROC_UNLOCK(imgp->proc);
imgp->entry_addr = entry;
More information about the svn-src-all
mailing list