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linux/arch/alpha/include/uapi/asm/siginfo.h

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Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
#ifndef _ALPHA_SIGINFO_H
#define _ALPHA_SIGINFO_H
#define __ARCH_SI_PREAMBLE_SIZE (4 * sizeof(int))
#define __ARCH_SI_TRAPNO
#include <asm-generic/siginfo.h>
signal/alpha: Document a conflict with SI_USER for SIGTRAP Setting si_code to __SI_FAULT results in a userspace seeing an si_code of 0. This is the same si_code as SI_USER. Posix and common sense requires that SI_USER not be a signal specific si_code. As such this use of 0 for the si_code is a pretty horribly broken ABI. Given that alpha is on it's last legs I don't know that it is worth fixing this, but it is worth documenting what is going on so that no one decides to copy this bad decision. This was introduced during the 2.5 development cycle so this mess has had a long time for people to be able to depend upon it. v2: Added FPE_FIXME for alpha as Helge Deller <deller@gmx.de> pointed out with his alternate patch one of the cases is SIGFPE not SIGTRAP. Cc: Helge Deller <deller@gmx.de> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: linux-alpha@vger.kernel.org Acked-by: Richard Henderson <rth@twiddle.net> History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Ref: 0a635c7a84cf ("Fill in siginfo_t.") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-06-27 02:38:04 +08:00
/*
* SIGFPE si_codes
*/
#ifdef __KERNEL__
signal: Remove kernel interal si_code magic struct siginfo is a union and the kernel since 2.4 has been hiding a union tag in the high 16bits of si_code using the values: __SI_KILL __SI_TIMER __SI_POLL __SI_FAULT __SI_CHLD __SI_RT __SI_MESGQ __SI_SYS While this looks plausible on the surface, in practice this situation has not worked well. - Injected positive signals are not copied to user space properly unless they have these magic high bits set. - Injected positive signals are not reported properly by signalfd unless they have these magic high bits set. - These kernel internal values leaked to userspace via ptrace_peek_siginfo - It was possible to inject these kernel internal values and cause the the kernel to misbehave. - Kernel developers got confused and expected these kernel internal values in userspace in kernel self tests. - Kernel developers got confused and set si_code to __SI_FAULT which is SI_USER in userspace which causes userspace to think an ordinary user sent the signal and that it was not kernel generated. - The values make it impossible to reorganize the code to transform siginfo_copy_to_user into a plain copy_to_user. As si_code must be massaged before being passed to userspace. So remove these kernel internal si codes and make the kernel code simpler and more maintainable. To replace these kernel internal magic si_codes introduce the helper function siginfo_layout, that takes a signal number and an si_code and computes which union member of siginfo is being used. Have siginfo_layout return an enumeration so that gcc will have enough information to warn if a switch statement does not handle all of union members. A couple of architectures have a messed up ABI that defines signal specific duplications of SI_USER which causes more special cases in siginfo_layout than I would like. The good news is only problem architectures pay the cost. Update all of the code that used the previous magic __SI_ values to use the new SIL_ values and to call siginfo_layout to get those values. Escept where not all of the cases are handled remove the defaults in the switch statements so that if a new case is missed in the future the lack will show up at compile time. Modify the code that copies siginfo si_code to userspace to just copy the value and not cast si_code to a short first. The high bits are no longer used to hold a magic union member. Fixup the siginfo header files to stop including the __SI_ values in their constants and for the headers that were missing it to properly update the number of si_codes for each signal type. The fixes to copy_siginfo_from_user32 implementations has the interesting property that several of them perviously should never have worked as the __SI_ values they depended up where kernel internal. With that dependency gone those implementations should work much better. The idea of not passing the __SI_ values out to userspace and then not reinserting them has been tested with criu and criu worked without changes. Ref: 2.4.0-test1 Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-07-17 11:36:59 +08:00
#define FPE_FIXME 0 /* Broken dup of SI_USER */
signal/alpha: Document a conflict with SI_USER for SIGTRAP Setting si_code to __SI_FAULT results in a userspace seeing an si_code of 0. This is the same si_code as SI_USER. Posix and common sense requires that SI_USER not be a signal specific si_code. As such this use of 0 for the si_code is a pretty horribly broken ABI. Given that alpha is on it's last legs I don't know that it is worth fixing this, but it is worth documenting what is going on so that no one decides to copy this bad decision. This was introduced during the 2.5 development cycle so this mess has had a long time for people to be able to depend upon it. v2: Added FPE_FIXME for alpha as Helge Deller <deller@gmx.de> pointed out with his alternate patch one of the cases is SIGFPE not SIGTRAP. Cc: Helge Deller <deller@gmx.de> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: linux-alpha@vger.kernel.org Acked-by: Richard Henderson <rth@twiddle.net> History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Ref: 0a635c7a84cf ("Fill in siginfo_t.") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-06-27 02:38:04 +08:00
#endif /* __KERNEL__ */
/*
* SIGTRAP si_codes
*/
#ifdef __KERNEL__
signal: Remove kernel interal si_code magic struct siginfo is a union and the kernel since 2.4 has been hiding a union tag in the high 16bits of si_code using the values: __SI_KILL __SI_TIMER __SI_POLL __SI_FAULT __SI_CHLD __SI_RT __SI_MESGQ __SI_SYS While this looks plausible on the surface, in practice this situation has not worked well. - Injected positive signals are not copied to user space properly unless they have these magic high bits set. - Injected positive signals are not reported properly by signalfd unless they have these magic high bits set. - These kernel internal values leaked to userspace via ptrace_peek_siginfo - It was possible to inject these kernel internal values and cause the the kernel to misbehave. - Kernel developers got confused and expected these kernel internal values in userspace in kernel self tests. - Kernel developers got confused and set si_code to __SI_FAULT which is SI_USER in userspace which causes userspace to think an ordinary user sent the signal and that it was not kernel generated. - The values make it impossible to reorganize the code to transform siginfo_copy_to_user into a plain copy_to_user. As si_code must be massaged before being passed to userspace. So remove these kernel internal si codes and make the kernel code simpler and more maintainable. To replace these kernel internal magic si_codes introduce the helper function siginfo_layout, that takes a signal number and an si_code and computes which union member of siginfo is being used. Have siginfo_layout return an enumeration so that gcc will have enough information to warn if a switch statement does not handle all of union members. A couple of architectures have a messed up ABI that defines signal specific duplications of SI_USER which causes more special cases in siginfo_layout than I would like. The good news is only problem architectures pay the cost. Update all of the code that used the previous magic __SI_ values to use the new SIL_ values and to call siginfo_layout to get those values. Escept where not all of the cases are handled remove the defaults in the switch statements so that if a new case is missed in the future the lack will show up at compile time. Modify the code that copies siginfo si_code to userspace to just copy the value and not cast si_code to a short first. The high bits are no longer used to hold a magic union member. Fixup the siginfo header files to stop including the __SI_ values in their constants and for the headers that were missing it to properly update the number of si_codes for each signal type. The fixes to copy_siginfo_from_user32 implementations has the interesting property that several of them perviously should never have worked as the __SI_ values they depended up where kernel internal. With that dependency gone those implementations should work much better. The idea of not passing the __SI_ values out to userspace and then not reinserting them has been tested with criu and criu worked without changes. Ref: 2.4.0-test1 Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-07-17 11:36:59 +08:00
#define TRAP_FIXME 0 /* Broken dup of SI_USER */
signal/alpha: Document a conflict with SI_USER for SIGTRAP Setting si_code to __SI_FAULT results in a userspace seeing an si_code of 0. This is the same si_code as SI_USER. Posix and common sense requires that SI_USER not be a signal specific si_code. As such this use of 0 for the si_code is a pretty horribly broken ABI. Given that alpha is on it's last legs I don't know that it is worth fixing this, but it is worth documenting what is going on so that no one decides to copy this bad decision. This was introduced during the 2.5 development cycle so this mess has had a long time for people to be able to depend upon it. v2: Added FPE_FIXME for alpha as Helge Deller <deller@gmx.de> pointed out with his alternate patch one of the cases is SIGFPE not SIGTRAP. Cc: Helge Deller <deller@gmx.de> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: linux-alpha@vger.kernel.org Acked-by: Richard Henderson <rth@twiddle.net> History Tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Ref: 0a635c7a84cf ("Fill in siginfo_t.") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2017-06-27 02:38:04 +08:00
#endif /* __KERNEL__ */
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-17 06:20:36 +08:00
#endif