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linux-kernelorg-stable/include/linux/instruction_pointer.h

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kernel.h: split out instruction pointer accessors bottom_half.h needs _THIS_IP_ to be standalone, so split that and _RET_IP_ out from kernel.h into the new instruction_pointer.h. kernel.h directly needs them, so include it there and replace the include of kernel.h with this new file in bottom_half.h. Link: https://lkml.kernel.org/r/20211028161248.45232-1-andriy.shevchenko@linux.intel.com Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-09 02:32:43 +00:00
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_INSTRUCTION_POINTER_H
#define _LINUX_INSTRUCTION_POINTER_H
x86/ibt: Suppress spurious ENDBR It was reported that under certain circumstances GCC emits ENDBR instructions for _THIS_IP_ usage. Specifically, when it appears at the start of a basic block -- but not elsewhere. Since _THIS_IP_ is never used for control flow, these ENDBR instructions are completely superfluous. Override the _THIS_IP_ definition for x86_64 to avoid this. Less ENDBR instructions is better. Fixes: 156ff4a544ae ("x86/ibt: Base IBT bits") Reported-by: David Kaplan <David.Kaplan@amd.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230802110323.016197440@infradead.org
2023-08-02 10:55:46 +00:00
#include <asm/linkage.h>
kernel.h: split out instruction pointer accessors bottom_half.h needs _THIS_IP_ to be standalone, so split that and _RET_IP_ out from kernel.h into the new instruction_pointer.h. kernel.h directly needs them, so include it there and replace the include of kernel.h with this new file in bottom_half.h. Link: https://lkml.kernel.org/r/20211028161248.45232-1-andriy.shevchenko@linux.intel.com Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-09 02:32:43 +00:00
#define _RET_IP_ (unsigned long)__builtin_return_address(0)
x86/ibt: Suppress spurious ENDBR It was reported that under certain circumstances GCC emits ENDBR instructions for _THIS_IP_ usage. Specifically, when it appears at the start of a basic block -- but not elsewhere. Since _THIS_IP_ is never used for control flow, these ENDBR instructions are completely superfluous. Override the _THIS_IP_ definition for x86_64 to avoid this. Less ENDBR instructions is better. Fixes: 156ff4a544ae ("x86/ibt: Base IBT bits") Reported-by: David Kaplan <David.Kaplan@amd.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230802110323.016197440@infradead.org
2023-08-02 10:55:46 +00:00
#ifndef _THIS_IP_
kernel.h: split out instruction pointer accessors bottom_half.h needs _THIS_IP_ to be standalone, so split that and _RET_IP_ out from kernel.h into the new instruction_pointer.h. kernel.h directly needs them, so include it there and replace the include of kernel.h with this new file in bottom_half.h. Link: https://lkml.kernel.org/r/20211028161248.45232-1-andriy.shevchenko@linux.intel.com Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-09 02:32:43 +00:00
#define _THIS_IP_ ({ __label__ __here; __here: (unsigned long)&&__here; })
x86/ibt: Suppress spurious ENDBR It was reported that under certain circumstances GCC emits ENDBR instructions for _THIS_IP_ usage. Specifically, when it appears at the start of a basic block -- but not elsewhere. Since _THIS_IP_ is never used for control flow, these ENDBR instructions are completely superfluous. Override the _THIS_IP_ definition for x86_64 to avoid this. Less ENDBR instructions is better. Fixes: 156ff4a544ae ("x86/ibt: Base IBT bits") Reported-by: David Kaplan <David.Kaplan@amd.com> Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20230802110323.016197440@infradead.org
2023-08-02 10:55:46 +00:00
#endif
kernel.h: split out instruction pointer accessors bottom_half.h needs _THIS_IP_ to be standalone, so split that and _RET_IP_ out from kernel.h into the new instruction_pointer.h. kernel.h directly needs them, so include it there and replace the include of kernel.h with this new file in bottom_half.h. Link: https://lkml.kernel.org/r/20211028161248.45232-1-andriy.shevchenko@linux.intel.com Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-09 02:32:43 +00:00
#endif /* _LINUX_INSTRUCTION_POINTER_H */