Patchwork [05/19] linux-user: fake /proc/self/stat

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Submitter riku.voipio@linaro.org
Date Feb. 3, 2012, 2:49 p.m.
Message ID <480b8e7dd56746c550a8ae9d7d1ba5d22cf1a4ee.1328280144.git.riku.voipio@linaro.org>
Download mbox | patch
Permalink /patch/139397/
State New
Headers show

Comments

riku.voipio@linaro.org - Feb. 3, 2012, 2:49 p.m.
From: Alexander Graf <agraf@suse.de>

The boehm gc finds the program's stack starting pointer by
checking /proc/self/stat. Unfortunately, so far it reads
qemu's stack pointer which clearly is wrong.

So let's instead fake the file so the guest program sees the
right address.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
---
 linux-user/syscall.c |   26 ++++++++++++++++++++++++++
 1 files changed, 26 insertions(+), 0 deletions(-)

Patch

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 1864d7f..5a5fdac 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -4614,6 +4614,31 @@  static int open_self_maps(void *cpu_env, int fd)
     return 0;
 }
 
+static int open_self_stat(void *cpu_env, int fd)
+{
+    TaskState *ts = ((CPUState *)cpu_env)->opaque;
+    abi_ulong start_stack = ts->info->start_stack;
+    int i;
+
+    for (i = 0; i < 44; i++) {
+      char buf[128];
+      int len;
+      uint64_t val = 0;
+
+      if (i == 27) {
+          /* stack bottom */
+          val = start_stack;
+      }
+      snprintf(buf, sizeof(buf), "%"PRId64 "%c", val, i == 43 ? '\n' : ' ');
+      len = strlen(buf);
+      if (write(fd, buf, len) != len) {
+          return -1;
+      }
+    }
+
+    return 0;
+}
+
 static int do_open(void *cpu_env, const char *pathname, int flags, mode_t mode)
 {
     struct fake_open {
@@ -4623,6 +4648,7 @@  static int do_open(void *cpu_env, const char *pathname, int flags, mode_t mode)
     const struct fake_open *fake_open;
     static const struct fake_open fakes[] = {
         { "/proc/self/maps", open_self_maps },
+        { "/proc/self/stat", open_self_stat },
         { NULL, NULL }
     };