2011-05-06 18:56:21

by Larry Finger

[permalink] [raw]
Subject: [PATCH] rtlwifi: Move 2 large arrays off stack

In driver rtlwifi, efuse_read() places two relatively large arrays on the
stack - a 1D u8 array of size 128, and a 2D array of u16 with 128 * 4 elements.
With driver rtl8192de, the sizes will be 256 and 256 * 4 respectively. As that
will make the 2D array be 2048 bytes, I have changed the code to use kmalloc to
allocate the space.

Signed-off-by: Larry Finger <[email protected]>
---

John,

This is 2.6.40 material.

Larry
---

Index: wireless-testing-new/drivers/net/wireless/rtlwifi/efuse.c
===================================================================
--- wireless-testing-new.orig/drivers/net/wireless/rtlwifi/efuse.c
+++ wireless-testing-new/drivers/net/wireless/rtlwifi/efuse.c
@@ -235,7 +235,7 @@ void read_efuse(struct ieee80211_hw *hw,
{
struct rtl_priv *rtlpriv = rtl_priv(hw);
struct rtl_efuse *rtlefuse = rtl_efuse(rtl_priv(hw));
- u8 efuse_tbl[HWSET_MAX_SIZE];
+ u8 *efuse_tbl;
u8 rtemp8[1];
u16 efuse_addr = 0;
u8 offset, wren;
@@ -245,7 +245,7 @@ void read_efuse(struct ieee80211_hw *hw,
rtlpriv->cfg->maps[EFUSE_MAX_SECTION_MAP];
const u32 efuse_len =
rtlpriv->cfg->maps[EFUSE_REAL_CONTENT_SIZE];
- u16 efuse_word[EFUSE_MAX_SECTION][EFUSE_MAX_WORD_UNIT];
+ u16 **efuse_word;
u16 efuse_utilized = 0;
u8 efuse_usage;

@@ -256,9 +256,24 @@ void read_efuse(struct ieee80211_hw *hw,
return;
}

+ /* allocate memory for efuse_tbl and efuse_word */
+ efuse_tbl = kmalloc(rtlpriv->cfg->maps[EFUSE_HWSET_MAX_SIZE] *
+ sizeof(u8), GFP_ATOMIC);
+ if (!efuse_tbl)
+ return;
+ efuse_word = kmalloc(EFUSE_MAX_WORD_UNIT * sizeof(u16 *), GFP_ATOMIC);
+ if (!efuse_word)
+ goto done;
+ for (i = 0; i < EFUSE_MAX_WORD_UNIT; i++) {
+ efuse_word[i] = kmalloc(efuse_max_section * sizeof(u16),
+ GFP_ATOMIC);
+ if (!efuse_word[i])
+ goto done;
+ }
+
for (i = 0; i < efuse_max_section; i++)
for (j = 0; j < EFUSE_MAX_WORD_UNIT; j++)
- efuse_word[i][j] = 0xFFFF;
+ efuse_word[j][i] = 0xFFFF;

read_efuse_byte(hw, efuse_addr, rtemp8);
if (*rtemp8 != 0xFF) {
@@ -285,7 +300,8 @@ void read_efuse(struct ieee80211_hw *hw,
read_efuse_byte(hw, efuse_addr, rtemp8);
efuse_addr++;
efuse_utilized++;
- efuse_word[offset][i] = (*rtemp8 & 0xff);
+ efuse_word[i][offset] =
+ (*rtemp8 & 0xff);

if (efuse_addr >= efuse_len)
break;
@@ -297,7 +313,7 @@ void read_efuse(struct ieee80211_hw *hw,
read_efuse_byte(hw, efuse_addr, rtemp8);
efuse_addr++;
efuse_utilized++;
- efuse_word[offset][i] |=
+ efuse_word[i][offset] |=
(((u16)*rtemp8 << 8) & 0xff00);

if (efuse_addr >= efuse_len)
@@ -320,9 +336,9 @@ void read_efuse(struct ieee80211_hw *hw,
for (i = 0; i < efuse_max_section; i++) {
for (j = 0; j < EFUSE_MAX_WORD_UNIT; j++) {
efuse_tbl[(i * 8) + (j * 2)] =
- (efuse_word[i][j] & 0xff);
+ (efuse_word[j][i] & 0xff);
efuse_tbl[(i * 8) + ((j * 2) + 1)] =
- ((efuse_word[i][j] >> 8) & 0xff);
+ ((efuse_word[j][i] >> 8) & 0xff);
}
}

@@ -336,6 +352,11 @@ void read_efuse(struct ieee80211_hw *hw,
(u8 *)&efuse_utilized);
rtlpriv->cfg->ops->set_hw_reg(hw, HW_VAR_EFUSE_USAGE,
(u8 *)&efuse_usage);
+done:
+ for (i = 0; i < EFUSE_MAX_WORD_UNIT; i++)
+ kfree(efuse_word[i]);
+ kfree(efuse_word);
+ kfree(efuse_tbl);
}

bool efuse_shadow_update_chk(struct ieee80211_hw *hw)