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authorJesper Juhl <jj@chaosbits.net>2010-12-25 19:57:41 +0100
committerIngo Molnar <mingo@elte.hu>2010-12-27 14:33:30 +0100
commit5cdd2de0a76d0ac47f107c8a7b32d75d25768dc1 (patch)
tree34b4834f0a377f571b050fd13abb4bc8a8da3821
parenteda4b716ea1f2a647a39cebae66b3fae4c4b80e4 (diff)
downloadlinux-sh-5cdd2de0a76d0ac47f107c8a7b32d75d25768dc1.tar.gz
x86/microcode: Fix double vfree() and remove redundant pointer checks before vfree()
In arch/x86/kernel/microcode_intel.c::generic_load_microcode() we have this: while (leftover) { ... if (get_ucode_data(mc, ucode_ptr, mc_size) || microcode_sanity_check(mc) < 0) { vfree(mc); break; } ... } if (mc) vfree(mc); This will cause a double free of 'mc'. This patch fixes that by just removing the vfree() call in the loop since 'mc' will be freed nicely just after we break out of the loop. There's also a second change in the patch. I noticed a lot of checks for pointers being NULL before passing them to vfree(). That's completely redundant since vfree() deals gracefully with being passed a NULL pointer. Removing the redundant checks yields a nice size decrease for the object file. Size before the patch: text data bss dec hex filename 4578 240 1032 5850 16da arch/x86/kernel/microcode_intel.o Size after the patch: text data bss dec hex filename 4489 240 984 5713 1651 arch/x86/kernel/microcode_intel.o Signed-off-by: Jesper Juhl <jj@chaosbits.net> Acked-by: Tigran Aivazian <tigran@aivazian.fsnet.co.uk> Cc: Shaohua Li <shaohua.li@intel.com> LKML-Reference: <alpine.LNX.2.00.1012251946100.10759@swampdragon.chaosbits.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--arch/x86/kernel/microcode_intel.c16
1 files changed, 5 insertions, 11 deletions
diff --git a/arch/x86/kernel/microcode_intel.c b/arch/x86/kernel/microcode_intel.c
index dcb65cc0a053..1a1b606d3e92 100644
--- a/arch/x86/kernel/microcode_intel.c
+++ b/arch/x86/kernel/microcode_intel.c
@@ -364,8 +364,7 @@ static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
/* For performance reasons, reuse mc area when possible */
if (!mc || mc_size > curr_mc_size) {
- if (mc)
- vfree(mc);
+ vfree(mc);
mc = vmalloc(mc_size);
if (!mc)
break;
@@ -374,13 +373,11 @@ static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
if (get_ucode_data(mc, ucode_ptr, mc_size) ||
microcode_sanity_check(mc) < 0) {
- vfree(mc);
break;
}
if (get_matching_microcode(&uci->cpu_sig, mc, new_rev)) {
- if (new_mc)
- vfree(new_mc);
+ vfree(new_mc);
new_rev = mc_header.rev;
new_mc = mc;
mc = NULL; /* trigger new vmalloc */
@@ -390,12 +387,10 @@ static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
leftover -= mc_size;
}
- if (mc)
- vfree(mc);
+ vfree(mc);
if (leftover) {
- if (new_mc)
- vfree(new_mc);
+ vfree(new_mc);
state = UCODE_ERROR;
goto out;
}
@@ -405,8 +400,7 @@ static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
goto out;
}
- if (uci->mc)
- vfree(uci->mc);
+ vfree(uci->mc);
uci->mc = (struct microcode_intel *)new_mc;
pr_debug("CPU%d found a matching microcode update with version 0x%x (current=0x%x)\n",