From: Tom Hughes <tom@compton.nu>
Date: Sat, 7 May 2005 17:57:39 +0000 (+0000)
Subject: Rework signal stack handling to avoid doing arithmetic on void pointers
X-Git-Tag: svn/VALGRIND_3_0_0~690
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=37aca15f81fe7a8877bc008b5f47813645149a8b;p=thirdparty%2Fvalgrind.git

Rework signal stack handling to avoid doing arithmetic on void pointers
and to avoid trashing the red zone while delivering a signal on the main
stack on amd64 systems.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@3628
---

diff --git a/coregrind/m_sigframe/sigframe-amd64-linux.c b/coregrind/m_sigframe/sigframe-amd64-linux.c
index c4a19bb888..80379c2f22 100644
--- a/coregrind/m_sigframe/sigframe-amd64-linux.c
+++ b/coregrind/m_sigframe/sigframe-amd64-linux.c
@@ -404,7 +404,8 @@ static Bool extend ( ThreadState *tst, Addr addr, SizeT size )
 
    /* For tracking memory events, indicate the entire frame has been
       allocated. */
-   VG_TRACK( new_mem_stack_signal, addr - VGA_STACK_REDZONE_SIZE, size );
+   VG_TRACK( new_mem_stack_signal, addr - VGA_STACK_REDZONE_SIZE,
+             size + VGA_STACK_REDZONE_SIZE );
 
    return True;
 }
@@ -600,7 +601,8 @@ void VG_(sigframe_destroy)( ThreadId tid, Bool isRT )
 
    size = restore_rt_sigframe(tst, (struct rt_sigframe *)rsp, &sigNo);
 
-   VG_TRACK( die_mem_stack_signal, rsp - VGA_STACK_REDZONE_SIZE, size );
+   VG_TRACK( die_mem_stack_signal, rsp - VGA_STACK_REDZONE_SIZE,
+             size + VGA_STACK_REDZONE_SIZE );
 
    if (VG_(clo_trace_signals))
       VG_(message)(
diff --git a/coregrind/m_sigframe/sigframe-x86-linux.c b/coregrind/m_sigframe/sigframe-x86-linux.c
index 56ba8cce1e..07e3c6dc50 100644
--- a/coregrind/m_sigframe/sigframe-x86-linux.c
+++ b/coregrind/m_sigframe/sigframe-x86-linux.c
@@ -425,7 +425,8 @@ static Bool extend ( ThreadState *tst, Addr addr, SizeT size )
 
    /* For tracking memory events, indicate the entire frame has been
       allocated. */
-   VG_TRACK( new_mem_stack_signal, addr - VGA_STACK_REDZONE_SIZE, size );
+   VG_TRACK( new_mem_stack_signal, addr - VGA_STACK_REDZONE_SIZE,
+             size + VGA_STACK_REDZONE_SIZE );
 
    return True;
 }
@@ -682,7 +683,8 @@ void VG_(sigframe_destroy)( ThreadId tid, Bool isRT )
    else
       size = restore_rt_sigframe(tst, (struct rt_sigframe *)esp, &sigNo);
 
-   VG_TRACK( die_mem_stack_signal, esp - VGA_STACK_REDZONE_SIZE, size );
+   VG_TRACK( die_mem_stack_signal, esp - VGA_STACK_REDZONE_SIZE,
+             size + VGA_STACK_REDZONE_SIZE );
 
    if (VG_(clo_trace_signals))
       VG_(message)(
diff --git a/coregrind/vg_signals.c b/coregrind/vg_signals.c
index 100a5bae96..94a9b142e1 100644
--- a/coregrind/vg_signals.c
+++ b/coregrind/vg_signals.c
@@ -474,10 +474,6 @@ void VG_(do_sys_sigaltstack) ( ThreadId tid )
 	 VG_(threads)[tid].altstack.ss_sp    = ss->ss_sp;
 	 VG_(threads)[tid].altstack.ss_size  = ss->ss_size;
 	 VG_(threads)[tid].altstack.ss_flags = 0;
-
-         VG_TRACK( new_mem_stack_signal,
-                   ss->ss_sp + ss->ss_size - VGA_STACK_REDZONE_SIZE,
-                   VGA_STACK_REDZONE_SIZE );
       }
    }
    SET_SYSCALL_RETVAL(tid, 0);
@@ -809,7 +805,7 @@ void push_signal_frame ( ThreadId tid, const vki_siginfo_t *siginfo )
       VG_TRACK( pre_deliver_signal, tid, sigNo, /*alt_stack*/True );
       
    } else {
-      esp_top_of_frame = STACK_PTR(tst->arch);
+      esp_top_of_frame = STACK_PTR(tst->arch) - VGA_STACK_REDZONE_SIZE;
 
       /* Signal delivery to tools */
       VG_TRACK( pre_deliver_signal, tid, sigNo, /*alt_stack*/False );