linux-kernel - [PATCH] arch/tile: clean up tile-specific PTRACE

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 13 Dec 2012 11:34:45 -0500
From:	Chris Metcalf <cmetcalf@...era.com>
To:	<linux-kernel@...r.kernel.org>, Oleg Nesterov <oleg@...hat.com>
Subject: [PATCH] arch/tile: clean up tile-specific PTRACE_SETOPTIONS

Use the newer idioms for setting PTRACE_O_xxx and PT_TRACE_xxx flags.
Only set/clear tile-specific flags if the generic routine returns
success, since otherwise we want to avoid setting any flags at all.
Atomically update the ptrace flags with the new values.  Eliminate
the PT_TRACE_MASK_TILE bitmask and just shift PTRACE_O_MASK_TILE.
Add a BUILD_BUG_ON to avoid overlapping with generic bits.

Signed-off-by: Chris Metcalf <cmetcalf@...era.com>
---
 arch/tile/include/asm/ptrace.h      |    3 +--
 arch/tile/include/uapi/asm/ptrace.h |    2 +-
 arch/tile/kernel/ptrace.c           |   10 +++++++---
 3 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/arch/tile/include/asm/ptrace.h b/arch/tile/include/asm/ptrace.h
index 1a4fd9a..5ce052e 100644
--- a/arch/tile/include/asm/ptrace.h
+++ b/arch/tile/include/asm/ptrace.h
@@ -24,8 +24,7 @@ typedef unsigned long pt_reg_t;
 #include <uapi/asm/ptrace.h>
 
 #define PTRACE_O_MASK_TILE	(PTRACE_O_TRACEMIGRATE)
-#define PT_TRACE_MIGRATE	0x00080000
-#define PT_TRACE_MASK_TILE	(PT_TRACE_MIGRATE)
+#define PT_TRACE_MIGRATE	PT_EVENT_FLAG(PTRACE_EVENT_MIGRATE)
 
 /* Flag bits in pt_regs.flags */
 #define PT_FLAGS_DISABLE_IRQ    1  /* on return to kernel, disable irqs */
diff --git a/arch/tile/include/uapi/asm/ptrace.h b/arch/tile/include/uapi/asm/ptrace.h
index 0d22088..7757e19 100644
--- a/arch/tile/include/uapi/asm/ptrace.h
+++ b/arch/tile/include/uapi/asm/ptrace.h
@@ -81,8 +81,8 @@ struct pt_regs {
 #define PTRACE_SETFPREGS	15
 
 /* Support TILE-specific ptrace options, with events starting at 16. */
-#define PTRACE_O_TRACEMIGRATE	0x00010000
 #define PTRACE_EVENT_MIGRATE	16
+#define PTRACE_O_TRACEMIGRATE	(1 << PTRACE_EVENT_MIGRATE)
 
 /*
  * Flag bits in pt_regs.flags that are part of the ptrace API.
diff --git a/arch/tile/kernel/ptrace.c b/arch/tile/kernel/ptrace.c
index 64ba102..b32bc3f 100644
--- a/arch/tile/kernel/ptrace.c
+++ b/arch/tile/kernel/ptrace.c
@@ -151,12 +151,16 @@ long arch_ptrace(struct task_struct *child, long request,
 
 	case PTRACE_SETOPTIONS:
 		/* Support TILE-specific ptrace options. */
-		child->ptrace &= ~PT_TRACE_MASK_TILE;
+		BUILD_BUG_ON(PTRACE_O_MASK_TILE & PTRACE_O_MASK);
 		tmp = data & PTRACE_O_MASK_TILE;
 		data &= ~PTRACE_O_MASK_TILE;
 		ret = ptrace_request(child, request, addr, data);
-		if (tmp & PTRACE_O_TRACEMIGRATE)
-			child->ptrace |= PT_TRACE_MIGRATE;
+		if (ret == 0) {
+			unsigned int flags = child->ptrace;
+			flags &= ~(PTRACE_O_MASK_TILE << PT_OPT_FLAG_SHIFT);
+			flags |= (tmp << PT_OPT_FLAG_SHIFT);
+			child->ptrace = flags;
+		}
 		break;
 
 	default:
-- 
1.7.10.3

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/