lkml.org 
[lkml]   [2021]   [Apr]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Date
Subject[PATCH 1/3] siginfo: Move si_trapno inside the union inside _si_fault

It turns out that linux uses si_trapno very sparingly, and as such it
can be considered extra information for a very narrow selection of
signals, rather than information that is present with every fault
reported in siginfo.

As such move si_trapno inside the union inside of _si_fault. This
results in no change in placement, and makes it eaiser to extend
_si_fault in the future as this reduces the number of special cases.
In particular with si_trapno included in the union it is no longer a
concern that the union must be pointer alligned on most architectures
because the union followes immediately after si_addr which is a
pointer.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
include/linux/compat.h | 4 +---
include/uapi/asm-generic/siginfo.h | 6 +-----
2 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/include/linux/compat.h b/include/linux/compat.h
index f0d2dd35d408..24462ed63af4 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -214,12 +214,10 @@ typedef struct compat_siginfo {
/* SIGILL, SIGFPE, SIGSEGV, SIGBUS, SIGTRAP, SIGEMT */
struct {
compat_uptr_t _addr; /* faulting insn/memory ref. */
-#ifdef __ARCH_SI_TRAPNO
- int _trapno; /* TRAP # which caused the signal */
-#endif
#define __COMPAT_ADDR_BND_PKEY_PAD (__alignof__(compat_uptr_t) < sizeof(short) ? \
sizeof(short) : __alignof__(compat_uptr_t))
union {
+ int _trapno; /* TRAP # which caused the signal */
/*
* used when si_code=BUS_MCEERR_AR or
* used when si_code=BUS_MCEERR_AO
diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h
index 03d6f6d2c1fe..2abdf1d19aad 100644
--- a/include/uapi/asm-generic/siginfo.h
+++ b/include/uapi/asm-generic/siginfo.h
@@ -63,9 +63,6 @@ union __sifields {
/* SIGILL, SIGFPE, SIGSEGV, SIGBUS, SIGTRAP, SIGEMT */
struct {
void __user *_addr; /* faulting insn/memory ref. */
-#ifdef __ARCH_SI_TRAPNO
- int _trapno; /* TRAP # which caused the signal */
-#endif
#ifdef __ia64__
int _imm; /* immediate value for "break" */
unsigned int _flags; /* see ia64 si_flags */
@@ -75,6 +72,7 @@ union __sifields {
#define __ADDR_BND_PKEY_PAD (__alignof__(void *) < sizeof(short) ? \
sizeof(short) : __alignof__(void *))
union {
+ int _trapno; /* TRAP # which caused the signal */
/*
* used when si_code=BUS_MCEERR_AR or
* used when si_code=BUS_MCEERR_AO
@@ -150,9 +148,7 @@ typedef struct siginfo {
#define si_int _sifields._rt._sigval.sival_int
#define si_ptr _sifields._rt._sigval.sival_ptr
#define si_addr _sifields._sigfault._addr
-#ifdef __ARCH_SI_TRAPNO
#define si_trapno _sifields._sigfault._trapno
-#endif
#define si_addr_lsb _sifields._sigfault._addr_lsb
#define si_lower _sifields._sigfault._addr_bnd._lower
#define si_upper _sifields._sigfault._addr_bnd._upper
--
2.30.1
\
 
 \ /
  Last update: 2021-05-01 00:51    [W:0.325 / U:0.004 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site