mirror of
https://github.com/raspberrypi/linux.git
synced 2025-12-20 08:42:06 +00:00
1154bbd326
For X86_FEATURE_SMAP alternatives which replace NOP with STAC or CLAC,
uaccess validation skips the NOP branch to avoid following impossible
code paths, e.g. where a STAC would be patched but a CLAC wouldn't.
However, it's not safe to assume an X86_FEATURE_SMAP alternative is
patching STAC/CLAC. There can be other alternatives, like
static_cpu_has(), where both branches need to be validated.
Fix that by repurposing ANNOTATE_IGNORE_ALTERNATIVE for skipping either
original instructions or new ones. This is a more generic approach
which enables the removal of the feature checking hacks and the
insn->ignore bit.
Fixes the following warnings:
arch/x86/mm/fault.o: warning: objtool: do_user_addr_fault+0x8ec: __stack_chk_fail() missing __noreturn in .c/.h or NORETURN() in noreturns.h
arch/x86/mm/fault.o: warning: objtool: do_user_addr_fault+0x8f1: unreachable instruction
[ mingo: Fix up conflicts with recent x86 changes. ]
Fixes: ea24213d80 ("objtool: Add UACCESS validation")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/de0621ca242130156a55d5d74fed86994dfa4c9c.1742852846.git.jpoimboe@kernel.org
Closes: https://lore.kernel.org/oe-kbuild-all/202503181736.zkZUBv4N-lkp@intel.com/
60 lines
1.2 KiB
C
60 lines
1.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _ASM_X86_HWEIGHT_H
|
|
#define _ASM_X86_HWEIGHT_H
|
|
|
|
#include <asm/cpufeatures.h>
|
|
|
|
#ifdef CONFIG_64BIT
|
|
#define REG_IN "D"
|
|
#define REG_OUT "a"
|
|
#else
|
|
#define REG_IN "a"
|
|
#define REG_OUT "a"
|
|
#endif
|
|
|
|
static __always_inline unsigned int __arch_hweight32(unsigned int w)
|
|
{
|
|
unsigned int res;
|
|
|
|
asm_inline (ALTERNATIVE(ANNOTATE_IGNORE_ALTERNATIVE
|
|
"call __sw_hweight32",
|
|
"popcntl %[val], %[cnt]", X86_FEATURE_POPCNT)
|
|
: [cnt] "=" REG_OUT (res), ASM_CALL_CONSTRAINT
|
|
: [val] REG_IN (w));
|
|
|
|
return res;
|
|
}
|
|
|
|
static inline unsigned int __arch_hweight16(unsigned int w)
|
|
{
|
|
return __arch_hweight32(w & 0xffff);
|
|
}
|
|
|
|
static inline unsigned int __arch_hweight8(unsigned int w)
|
|
{
|
|
return __arch_hweight32(w & 0xff);
|
|
}
|
|
|
|
#ifdef CONFIG_X86_32
|
|
static inline unsigned long __arch_hweight64(__u64 w)
|
|
{
|
|
return __arch_hweight32((u32)w) +
|
|
__arch_hweight32((u32)(w >> 32));
|
|
}
|
|
#else
|
|
static __always_inline unsigned long __arch_hweight64(__u64 w)
|
|
{
|
|
unsigned long res;
|
|
|
|
asm_inline (ALTERNATIVE(ANNOTATE_IGNORE_ALTERNATIVE
|
|
"call __sw_hweight64",
|
|
"popcntq %[val], %[cnt]", X86_FEATURE_POPCNT)
|
|
: [cnt] "=" REG_OUT (res), ASM_CALL_CONSTRAINT
|
|
: [val] REG_IN (w));
|
|
|
|
return res;
|
|
}
|
|
#endif /* CONFIG_X86_32 */
|
|
|
|
#endif
|