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authorDenys Vlasenko2016-09-30 11:21:21 +0200
committerDenys Vlasenko2016-09-30 11:21:21 +0200
commit60ca8343589ff6edb5a447551718e816555af494 (patch)
tree185d67d64a69966284da66fdfdccf4e365221957 /shell
parent08755f9bcb2d272ed32687883b410910d34c50dc (diff)
downloadbusybox-60ca8343589ff6edb5a447551718e816555af494.zip
busybox-60ca8343589ff6edb5a447551718e816555af494.tar.gz
ash: [MEMALLOC] Add pushstackmark
Upstream commit: Author: Herbert Xu <herbert@gondor.apana.org.au> Date: Sat Oct 6 00:45:52 2007 +0800 [MEMALLOC] Add pushstackmark This patch gets rid of the stack mark tracking hack by allocating a little bit of stack memory if we're at risk of planting a stack mark which may be grown later. To do this a new function pushstackmark is added which lets the user pick a bigger amount to allocate since some users do that anyway after setting a stack mark. Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'shell')
-rw-r--r--shell/ash.c53
1 files changed, 19 insertions, 34 deletions
diff --git a/shell/ash.c b/shell/ash.c
index 97f8d93..f7ce698 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -1371,13 +1371,11 @@ struct stackmark {
struct stack_block *stackp;
char *stacknxt;
size_t stacknleft;
- struct stackmark *marknext;
};
struct globals_memstack {
struct stack_block *g_stackp; // = &stackbase;
- struct stackmark *markp;
char *g_stacknxt; // = stackbase.space;
char *sstrend; // = stackbase.space + MINSIZE;
size_t g_stacknleft; // = MINSIZE;
@@ -1387,7 +1385,6 @@ struct globals_memstack {
extern struct globals_memstack *const ash_ptr_to_globals_memstack;
#define G_memstack (*ash_ptr_to_globals_memstack)
#define g_stackp (G_memstack.g_stackp )
-#define markp (G_memstack.markp )
#define g_stacknxt (G_memstack.g_stacknxt )
#define sstrend (G_memstack.sstrend )
#define g_stacknleft (G_memstack.g_stacknleft)
@@ -1478,13 +1475,26 @@ sstrdup(const char *p)
}
static void
-setstackmark(struct stackmark *mark)
+grabstackblock(size_t len)
+{
+ len = SHELL_ALIGN(len);
+ g_stacknxt += len;
+ g_stacknleft -= len;
+}
+
+static void
+pushstackmark(struct stackmark *mark, size_t len)
{
mark->stackp = g_stackp;
mark->stacknxt = g_stacknxt;
mark->stacknleft = g_stacknleft;
- mark->marknext = markp;
- markp = mark;
+ grabstackblock(len);
+}
+
+static void
+setstackmark(struct stackmark *mark)
+{
+ pushstackmark(mark, g_stacknxt == g_stackp->space && g_stackp != &stackbase);
}
static void
@@ -1496,7 +1506,6 @@ popstackmark(struct stackmark *mark)
return;
INT_OFF;
- markp = mark->marknext;
while (g_stackp != mark->stackp) {
sp = g_stackp;
g_stackp = sp->prev;
@@ -1530,7 +1539,6 @@ growstackblock(void)
if (g_stacknxt == g_stackp->space && g_stackp != &stackbase) {
struct stack_block *oldstackp;
- struct stackmark *xmark;
struct stack_block *sp;
struct stack_block *prevstackp;
size_t grosslen;
@@ -1546,18 +1554,6 @@ growstackblock(void)
g_stacknxt = sp->space;
g_stacknleft = newlen;
sstrend = sp->space + newlen;
-
- /*
- * Stack marks pointing to the start of the old block
- * must be relocated to point to the new block
- */
- xmark = markp;
- while (xmark != NULL && xmark->stackp == oldstackp) {
- xmark->stackp = g_stackp;
- xmark->stacknxt = g_stacknxt;
- xmark->stacknleft = g_stacknleft;
- xmark = xmark->marknext;
- }
INT_ON;
} else {
char *oldspace = g_stacknxt;
@@ -1570,14 +1566,6 @@ growstackblock(void)
}
}
-static void
-grabstackblock(size_t len)
-{
- len = SHELL_ALIGN(len);
- g_stacknxt += len;
- g_stacknleft -= len;
-}
-
/*
* The following routines are somewhat easier to use than the above.
* The user declares a variable of type STACKSTR, which may be declared
@@ -2482,8 +2470,7 @@ setprompt_if(smallint do_set, int whichprompt)
prompt = nullstr;
}
#if ENABLE_ASH_EXPAND_PRMT
- setstackmark(&smark);
- stalloc(stackblocksize());
+ pushstackmark(&smark, stackblocksize());
#endif
putprompt(expandstr(prompt));
#if ENABLE_ASH_EXPAND_PRMT
@@ -5938,10 +5925,8 @@ expbackq(union node *cmd, int flag)
struct stackmark smark;
INT_OFF;
- setstackmark(&smark);
- dest = expdest;
- startloc = dest - (char *)stackblock();
- grabstackstr(dest);
+ startloc = expdest - (char *)stackblock();
+ pushstackmark(&smark, startloc);
evalbackcmd(cmd, &in);
popstackmark(&smark);