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[PATCH V5 1/2] Initialize bnd register before performing inferior calls.
- From: Walfred Tedeschi <walfred dot tedeschi at intel dot com>
- To: palves at redhat dot com, brobecker at adacore dot com
- Cc: gdb-patches at sourceware dot org, Walfred Tedeschi <walfred dot tedeschi at intel dot com>
- Date: Fri, 18 Mar 2016 15:16:05 +0100
- Subject: [PATCH V5 1/2] Initialize bnd register before performing inferior calls.
- Authentication-results: sourceware.org; auth=none
BND registers should be initialized before performing an inferior call
to avoid undesired bound violations.
2016-02-03 Walfred Tedeschi <walfred.tedeschi@intel.com>
gdb/ChangeLog:
* i387-tdep.h (i387_reset_bnd_regs): New.
* i387-tdep.c (i387_reset_bnd_regs): New.
* i386-tdep.c (i386_push_dummy_call): Call i387_reset_bnd_regs.
* amd64-tdep (amd64_push_dummy_call): Call i387_reset_bnd_regs.
---
gdb/amd64-tdep.c | 5 +++++
gdb/i386-tdep.c | 5 +++++
gdb/i387-tdep.c | 16 ++++++++++++++++
gdb/i387-tdep.h | 6 ++++++
4 files changed, 32 insertions(+)
diff --git a/gdb/amd64-tdep.c b/gdb/amd64-tdep.c
index a62efde..c1aca26 100644
--- a/gdb/amd64-tdep.c
+++ b/gdb/amd64-tdep.c
@@ -997,6 +997,11 @@ amd64_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
gdb_byte buf[8];
+ /* When MPX is enabled, all bnd registers have to be initialized
+ before the call. This avoids an undesired bound violation
+ during the function's execution. */
+ i387_reset_bnd_regs (gdbarch, regcache);
+
/* Pass arguments. */
sp = amd64_push_arguments (regcache, nargs, args, sp, struct_return);
diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index 4c66edf..e8d41a3 100644
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -2665,6 +2665,11 @@ i386_push_dummy_call (struct gdbarch *gdbarch, struct value *function,
int write_pass;
int args_space = 0;
+ /* When MPX is enabled, all bnd registers have to be initialized
+ before the call. This avoids an undesired bound violation
+ during the function's execution. */
+ i387_reset_bnd_regs (gdbarch, regcache);
+
/* Determine the total space required for arguments and struct
return address in a first pass (allowing for 16-byte-aligned
arguments), then push arguments in a second pass. */
diff --git a/gdb/i387-tdep.c b/gdb/i387-tdep.c
index f7a3b55..9bb3177 100644
--- a/gdb/i387-tdep.c
+++ b/gdb/i387-tdep.c
@@ -1772,3 +1772,19 @@ i387_return_value (struct gdbarch *gdbarch, struct regcache *regcache)
regcache_raw_write_unsigned (regcache, I387_FTAG_REGNUM (tdep), 0x3fff);
}
+
+void
+i387_reset_bnd_regs (struct gdbarch *gdbarch, struct regcache *regcache)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ if (I387_BND0R_REGNUM (tdep) > 0)
+ {
+ gdb_byte bnd_buf[16];
+ int i;
+
+ memset (bnd_buf, 0, 16);
+ for (i = 0; i < I387_BND0R_REGNUM (tdep); i++)
+ regcache_raw_write (regcache, I387_BND0R_REGNUM (tdep) + i, bnd_buf);
+ }
+}
diff --git a/gdb/i387-tdep.h b/gdb/i387-tdep.h
index b4dc2b7..3ac4b4d 100644
--- a/gdb/i387-tdep.h
+++ b/gdb/i387-tdep.h
@@ -156,4 +156,10 @@ extern void i387_collect_xsave (const struct regcache *regcache,
extern void i387_return_value (struct gdbarch *gdbarch,
struct regcache *regcache);
+/* Set all bnd registers to the INIT state. INIT state means
+ all memory range can be accessed. */
+
+extern void i387_reset_bnd_regs (struct gdbarch *gdbarch,
+ struct regcache *regcache);
+
#endif /* i387-tdep.h */
--
2.1.4