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tile: support simulator notification for ET_DYN objects 

The tile code notifies the simulator of new ET_EXEC objects starting
to execute so that tracing code can properly annotate the objects.
However, we didn't support ET_DYN executables like ld.so, so we
didn't properly load symbols, etc.  This change enables that support;
we use a variant of the SIM_CONTROL_DLOPEN simulator notification
that newer simulators will recognize and use to set the base address
for the next SIM_CONTROL_OS_EXEC notification.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This commit is contained in:
Chris Metcalf 2013-08-07 14:07:03 -04:00
parent 70d2b5958a
commit 0c1d1917c5
1 changed files with 47 additions and 13 deletions
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60
arch/tile/mm/elf.c
View File

@ -21,7 +21,7 @@
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/sections.h>
#include <arch/sim_def.h>
#include <arch/sim.h>
/* Notify a running simulator, if any, that an exec just occurred. */
static void sim_notify_exec(const char *binary_name)
@ -38,21 +38,55 @@ static void sim_notify_exec(const char *binary_name)
static int notify_exec(struct mm_struct *mm)
{
int retval = 0; /* failure */
char *buf, *path;
struct vm_area_struct *vma;
if (mm->exe_file) {
char *buf = (char *) __get_free_page(GFP_KERNEL);
if (buf) {
char *path = d_path(&mm->exe_file->f_path,
buf, PAGE_SIZE);
if (!IS_ERR(path)) {
sim_notify_exec(path);
retval = 1;
}
free_page((unsigned long)buf);
if (!sim_is_simulator())
return 1;
if (mm->exe_file == NULL)
return 0;
for (vma = current->mm->mmap; ; vma = vma->vm_next) {
if (vma == NULL)
return 0;
if (vma->vm_file == mm->exe_file)
break;
}
buf = (char *) __get_free_page(GFP_KERNEL);
if (buf == NULL)
return 0;
path = d_path(&mm->exe_file->f_path, buf, PAGE_SIZE);
if (IS_ERR(path)) {
free_page((unsigned long)buf);
return 0;
}
/*
* Notify simulator of an ET_DYN object so we know the load address.
* The somewhat cryptic overuse of SIM_CONTROL_DLOPEN allows us
* to be backward-compatible with older simulator releases.
*/
if (vma->vm_start == (ELF_ET_DYN_BASE & PAGE_MASK)) {
char buf[64];
int i;
snprintf(buf, sizeof(buf), "0x%lx:@", vma->vm_start);
for (i = 0; ; ++i) {
char c = buf[i];
__insn_mtspr(SPR_SIM_CONTROL,
(SIM_CONTROL_DLOPEN
| (c << _SIM_CONTROL_OPERATOR_BITS)));
if (c == '\0')
break;
}
}
return retval;
sim_notify_exec(path);
free_page((unsigned long)buf);
return 1;
}
/* Notify a running simulator, if any, that we loaded an interpreter. */