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arm: bugfix: save_boot_params_default accesses uninitalized stack when -O0

PATCH Superseded Tetsuyuki Kobayashi 1 participant 2 messages Jun 28, 2012 Arm (32-bit)

v2 of 5 Superseded Latest is v5 →

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PATCH v2 1/1 arm: bugfix: save_boot_params_default accesses uninitalized stack when -O0

save_boot_params_default() in cpu.c accesses uninitialized stack area when it compiled with -O0 (not optimized).

---
Changes for v2:
- include <linux/compiler.h> and use __naked instead of __attribute__((naked))

 arch/arm/cpu/armv7/cpu.c |    4 ++++
 1 file changed, 4 insertions(+)
arch/arm/cpu/armv7/cpu.c +4 -0
index c6fa8ef..3e2a75c 100644
@@ -36,9 +36,13 @@
 #include <asm/system.h>
 #include <asm/cache.h>
 #include <asm/armv7.h>
+#include <linux/compiler.h>
 
+__naked /* don't save anything to stack even if compiled with -O0 */
 void save_boot_params_default(u32 r0, u32 r1, u32 r2, u32 r3)
 {
+	/* stack is not yet initialized */
+	asm("bx lr");
 }
 
 void save_boot_params(u32 r0, u32 r1, u32 r2, u32 r3)
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1.7.9.5
#1 lore raw

PATCH v2 1/1 arm: bugfix: save_boot_params_default accesses uninitalized stack when -O0

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Quoted 30 lines · Tetsuyuki Kobayashi

save_boot_params_default() in cpu.c accesses uninitialized stack area when it compiled with -O0 (not optimized).

---
Changes for v2:
- include<linux/compiler.h> and use __naked instead of __attribute__((naked))

  arch/arm/cpu/armv7/cpu.c |    4 ++++
  1 file changed, 4 insertions(+)
arch/arm/cpu/armv7/cpu.c +4 -0
index c6fa8ef..3e2a75c 100644
@@ -36,9 +36,13 @@
  #include<asm/system.h>
  #include<asm/cache.h>
  #include<asm/armv7.h>
+#include<linux/compiler.h>
 
+__naked /* don't save anything to stack even if compiled with -O0 */
  void save_boot_params_default(u32 r0, u32 r1, u32 r2, u32 r3)
  {
+	/* stack is not yet initialized */
+	asm("bx lr");
  }
 
  void save_boot_params(u32 r0, u32 r1, u32 r2, u32 r3)