From: "Eric W. Biederman" <ebiederm@xmission.com>
To: linux-kernel@vger.kernel.org
Cc: Al Viro <viro@zeniv.linux.org.uk>,
Oleg Nesterov <oleg@redhat.com>,
linux-arch@vger.kernel.org, Ram Pai <linuxram@us.ibm.com>,
"Eric W. Biederman" <ebiederm@xmission.com>
Subject: [PATCH 08/10] signal/ptrace: Add force_sig_ptrace_errno_trap and use it where needed
Date: Tue, 23 Jan 2018 15:07:17 -0600 [thread overview]
Message-ID: <20180123210719.10456-8-ebiederm@xmission.com> (raw)
In-Reply-To: <87607s5lra.fsf_-_@xmission.com>
There are so many places that build struct siginfo by hand that at
least one of them is bound to get it wrong. A handful of cases in the
kernel arguably did just that when using the errno field of siginfo to
pass no errno values to userspace. The usage is limited to a single
si_code so at least does not mess up anything else.
Encapsulate this questionable pattern in a helper function so
that the userspace ABI is preserved.
Update all of the places that use this pattern to use the new helper
function.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
arch/arm/kernel/ptrace.c | 8 +-------
arch/arm64/kernel/ptrace.c | 6 ++++--
arch/powerpc/kernel/process.c | 9 ++-------
arch/xtensa/kernel/ptrace.c | 8 +-------
include/linux/sched/signal.h | 2 ++
kernel/signal.c | 15 +++++++++++++++
6 files changed, 25 insertions(+), 23 deletions(-)
diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index 58e3771e4c5b..7724b0f661b3 100644
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -390,7 +390,6 @@ static void ptrace_hbptriggered(struct perf_event *bp,
struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
long num;
int i;
- siginfo_t info;
for (i = 0; i < ARM_MAX_HBP_SLOTS; ++i)
if (current->thread.debug.hbp[i] == bp)
@@ -398,12 +397,7 @@ static void ptrace_hbptriggered(struct perf_event *bp,
num = (i == ARM_MAX_HBP_SLOTS) ? 0 : ptrace_hbp_idx_to_num(i);
- info.si_signo = SIGTRAP;
- info.si_errno = (int)num;
- info.si_code = TRAP_HWBKPT;
- info.si_addr = (void __user *)(bkpt->trigger);
-
- force_sig_info(SIGTRAP, &info, current);
+ force_sig_ptrace_errno_trap((int)num, (void __user *)(bkpt->trigger));
}
/*
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 95daa1478a7c..6618036ae6d4 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -190,21 +190,23 @@ static void ptrace_hbptriggered(struct perf_event *bp,
#ifdef CONFIG_COMPAT
if (is_compat_task()) {
+ int si_errno = 0;
int i;
for (i = 0; i < ARM_MAX_BRP; ++i) {
if (current->thread.debug.hbp_break[i] == bp) {
- info.si_errno = (i << 1) + 1;
+ si_errno = (i << 1) + 1;
break;
}
}
for (i = 0; i < ARM_MAX_WRP; ++i) {
if (current->thread.debug.hbp_watch[i] == bp) {
- info.si_errno = -((i << 1) + 1);
+ si_errno = -((i << 1) + 1);
break;
}
}
+ force_sig_ptrace_errno_trap(si_errno, (void __user *)bkpt->trigger);
}
#endif
force_sig_info(SIGTRAP, &info, current);
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index bfb48cf56bc3..4208cbe2fb7f 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -603,19 +603,14 @@ EXPORT_SYMBOL(flush_all_to_thread);
void do_send_trap(struct pt_regs *regs, unsigned long address,
unsigned long error_code, int breakpt)
{
- siginfo_t info;
-
current->thread.trap_nr = TRAP_HWBKPT;
if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
11, SIGSEGV) == NOTIFY_STOP)
return;
/* Deliver the signal to userspace */
- info.si_signo = SIGTRAP;
- info.si_errno = breakpt; /* breakpoint or watchpoint id */
- info.si_code = TRAP_HWBKPT;
- info.si_addr = (void __user *)address;
- force_sig_info(SIGTRAP, &info, current);
+ force_sig_ptrace_errno_trap(breakpt, /* breakpoint or watchpoint id */
+ (void __user *)address);
}
#else /* !CONFIG_PPC_ADV_DEBUG_REGS */
void do_break (struct pt_regs *regs, unsigned long address,
diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c
index e2461968efb2..c0845cb1cbb9 100644
--- a/arch/xtensa/kernel/ptrace.c
+++ b/arch/xtensa/kernel/ptrace.c
@@ -278,7 +278,6 @@ static void ptrace_hbptriggered(struct perf_event *bp,
struct pt_regs *regs)
{
int i;
- siginfo_t info;
struct arch_hw_breakpoint *bkpt = counter_arch_bp(bp);
if (bp->attr.bp_type & HW_BREAKPOINT_X) {
@@ -293,12 +292,7 @@ static void ptrace_hbptriggered(struct perf_event *bp,
i = (i << 1) | 1;
}
- info.si_signo = SIGTRAP;
- info.si_errno = i;
- info.si_code = TRAP_HWBKPT;
- info.si_addr = (void __user *)bkpt->address;
-
- force_sig_info(SIGTRAP, &info, current);
+ force_sig_ptrace_errno_trap(i, (void __user *)bkpt->address);
}
static struct perf_event *ptrace_hbp_create(struct task_struct *tsk, int type)
diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h
index 944fe6356f4a..23b4f9cb82db 100644
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -311,6 +311,8 @@ int send_sig_mceerr(int code, void __user *, short, struct task_struct *);
int force_sig_bnderr(void __user *addr, void __user *lower, void __user *upper);
int force_sig_pkuerr(void __user *addr, u32 pkey);
+int force_sig_ptrace_errno_trap(int errno, void __user *addr);
+
extern int send_sig_info(int, struct siginfo *, struct task_struct *);
extern int force_sigsegv(int, struct task_struct *);
extern int force_sig_info(int, struct siginfo *, struct task_struct *);
diff --git a/kernel/signal.c b/kernel/signal.c
index 4f6300ef8062..e549174c0831 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -1599,6 +1599,21 @@ int force_sig_pkuerr(void __user *addr, u32 pkey)
}
#endif
+/* For the crazy architectures that include trap information in
+ * the errno field, instead of an actual errno value.
+ */
+int force_sig_ptrace_errno_trap(int errno, void __user *addr)
+{
+ struct siginfo info;
+
+ clear_siginfo(&info);
+ info.si_signo = SIGTRAP;
+ info.si_errno = errno;
+ info.si_code = TRAP_HWBKPT;
+ info.si_addr = addr;
+ return force_sig_info(info.si_signo, &info, current);
+}
+
int kill_pgrp(struct pid *pid, int sig, int priv)
{
int ret;
--
2.14.1
next prev parent reply other threads:[~2018-01-23 21:10 UTC|newest]
Thread overview: 89+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-12 0:57 [PATCH 00/11] siginfo fixes/cleanups esp SI_USER Eric W. Biederman
2018-01-12 0:59 ` [PATCH 01/11] signal: Simplify and fix kdb_send_sig Eric W. Biederman
2018-01-12 0:59 ` [PATCH 02/11] signal/sh: Ensure si_signo is initialized in do_divide_error Eric W. Biederman
2018-01-12 0:59 ` [PATCH 03/11] signal/openrisc: Fix do_unaligned_access to send the proper signal Eric W. Biederman
2018-01-12 13:25 ` Stafford Horne
2018-01-12 17:37 ` Eric W. Biederman
2018-01-12 0:59 ` [PATCH 04/11] signal/parisc: Document a conflict with SI_USER with SIGFPE Eric W. Biederman
2018-01-12 22:29 ` Helge Deller
2018-01-13 21:06 ` Eric W. Biederman
2018-01-14 1:46 ` Eric W. Biederman
2018-02-23 0:15 ` Eric W. Biederman
2018-02-25 19:49 ` Helge Deller
2018-02-27 2:19 ` Eric W. Biederman
2018-01-12 0:59 ` [PATCH 05/11] signal/metag: " Eric W. Biederman
2018-01-12 0:59 ` [PATCH 06/11] signal/powerpc: Document conflicts with SI_USER and SIGFPE and SIGTRAP Eric W. Biederman
2018-01-12 0:59 ` [PATCH 07/11] signal/arm64: Document conflicts with SI_USER and SIGFPE,SIGTRAP,SIGBUS Eric W. Biederman
2018-01-15 16:30 ` [PATCH 07/11] signal/arm64: Document conflicts with SI_USER and SIGFPE, SIGTRAP, SIGBUS Dave Martin
2018-01-15 17:23 ` Eric W. Biederman
2018-01-16 17:24 ` Dave Martin
2018-01-16 22:28 ` Eric W. Biederman
2018-01-17 11:46 ` Dave Martin
2018-01-17 11:57 ` Russell King - ARM Linux
2018-01-17 12:15 ` Dave Martin
2018-01-17 12:37 ` Russell King - ARM Linux
2018-01-17 15:37 ` Dave Martin
2018-01-17 15:49 ` Russell King - ARM Linux
2018-01-17 16:11 ` Dave Martin
2018-01-17 16:45 ` Eric W. Biederman
2018-01-17 17:14 ` Russell King - ARM Linux
2018-01-24 21:28 ` Eric W. Biederman
2018-01-17 17:17 ` Dave Martin
2018-01-17 17:24 ` Eric W. Biederman
2018-01-17 17:39 ` Dave Martin
2018-01-15 19:30 ` James Morse
2018-01-12 0:59 ` [PATCH 08/11] signal/arm: Document conflicts with SI_USER and SIGFPE Eric W. Biederman
2018-01-15 17:49 ` Russell King - ARM Linux
2018-01-15 20:12 ` Eric W. Biederman
2018-01-16 17:41 ` Dave Martin
2018-01-19 12:05 ` Dave Martin
2018-01-12 0:59 ` [PATCH 09/11] signal: Reduce copy_siginfo to just a memcpy Eric W. Biederman
2018-01-12 0:59 ` [PATCH 10/11] signal: Introduce clear_siginfo Eric W. Biederman
2018-01-12 0:59 ` [PATCH 11/11] signal: Ensure generic siginfos the kernel sends have all bits initialized Eric W. Biederman
2018-01-12 20:29 ` [PATCH 0/2] siginfo fixes Eric W. Biederman
2018-01-12 20:31 ` [PATCH 1/2] mn10300/misalignment: Use SIGSEGV SEGV_MAPERR to report a failed user copy Eric W. Biederman
2018-01-12 20:31 ` [PATCH 2/2] x86/mm/pkeys: Fix fill_sig_info_pkey Eric W. Biederman
2018-01-14 11:44 ` [tip:x86/urgent] " tip-bot for Eric W. Biederman
2018-01-16 0:39 ` [PATCH 00/22] siginfo unification Eric W. Biederman
2018-01-16 0:39 ` [PATCH 01/22] signal: Document all of the signals that use the _sigfault union member Eric W. Biederman
2018-01-16 0:39 ` [PATCH 02/22] signal: Document the strange si_codes used by ptrace event stops Eric W. Biederman
2018-01-16 0:39 ` [PATCH 03/22] signal: Document glibc's si_code of SI_ASYNCNL Eric W. Biederman
2018-01-16 0:39 ` [PATCH 04/22] signal: Ensure no siginfo union member increases the size of struct siginfo Eric W. Biederman
2018-01-16 0:39 ` [PATCH 05/22] signal: Clear si_sys_private before copying siginfo to userspace Eric W. Biederman
2018-01-16 0:39 ` [PATCH 06/22] signal: Remove _sys_private and _overrun_incr from struct compat_siginfo Eric W. Biederman
2018-01-16 0:39 ` [PATCH 07/22] ia64/signal: switch to generic struct siginfo Eric W. Biederman
2018-01-16 0:39 ` [PATCH 08/22] signal/ia64: switch the last arch-specific copy_siginfo_to_user() to generic version Eric W. Biederman
2018-01-16 0:39 ` [PATCH 09/22] signal/mips: switch mips to generic siginfo Eric W. Biederman
2018-01-16 0:39 ` [PATCH 10/22] signal: Remove unnecessary ifdefs now that there is only one struct siginfo Eric W. Biederman
2018-01-16 0:39 ` [PATCH 11/22] signal: kill __ARCH_SI_UID_T Eric W. Biederman
2018-01-16 0:39 ` [PATCH 12/22] signal: unify compat_siginfo_t Eric W. Biederman
2018-01-16 0:40 ` [PATCH 13/22] signal: Move addr_lsb into the _sigfault union for clarity Eric W. Biederman
2018-03-16 19:00 ` Dave Hansen
2018-03-16 19:24 ` Dave Hansen
2018-03-16 20:06 ` Eric W. Biederman
2018-03-16 20:33 ` Dave Hansen
2018-03-16 21:08 ` Eric W. Biederman
2018-01-16 0:40 ` [PATCH 14/22] signal/powerpc: Remove redefinition of NSIGTRAP on powerpc Eric W. Biederman
2018-01-16 0:40 ` [PATCH 15/22] signal/ia64: Move the ia64 specific si_codes to asm-generic/siginfo.h Eric W. Biederman
2018-01-16 0:40 ` [PATCH 16/22] signal/frv: Move the frv " Eric W. Biederman
2018-01-16 0:40 ` [PATCH 17/22] signal/tile: Move the tile " Eric W. Biederman
2018-01-16 0:40 ` [PATCH 18/22] signal/blackfin: Move the blackfin " Eric W. Biederman
2018-01-16 0:40 ` [PATCH 19/22] signal/blackfin: Remove pointless UID16_SIGINFO_COMPAT_NEEDED Eric W. Biederman
2018-01-16 0:40 ` [PATCH 20/22] signal: Unify and correct copy_siginfo_from_user32 Eric W. Biederman
2018-01-16 0:40 ` [PATCH 21/22] signal: Remove the code to clear siginfo before calling copy_siginfo_from_user32 Eric W. Biederman
2018-01-16 0:40 ` [PATCH 22/22] signal: Unify and correct copy_siginfo_to_user32 Eric W. Biederman
2018-01-19 18:03 ` Al Viro
2018-01-19 21:04 ` Eric W. Biederman
2018-01-23 21:05 ` [PATCH 00/10] siginfo infrastructure Eric W. Biederman
2018-01-23 21:07 ` [PATCH 01/10] ptrace: Use copy_siginfo in setsiginfo and getsiginfo Eric W. Biederman
2018-01-23 21:07 ` [PATCH 02/10] signal/arm64: Better isolate the COMPAT_TASK portion of ptrace_hbptriggered Eric W. Biederman
2018-01-23 21:07 ` [PATCH 03/10] signal: Don't use structure initializers for struct siginfo Eric W. Biederman
2018-01-23 21:07 ` [PATCH 04/10] signal: Replace memset(info,...) with clear_siginfo for clarity Eric W. Biederman
2018-01-23 21:07 ` [PATCH 05/10] signal: Add send_sig_fault and force_sig_fault Eric W. Biederman
2018-01-23 21:07 ` [PATCH 06/10] signal: Helpers for faults with specialized siginfo layouts Eric W. Biederman
2018-01-24 19:26 ` Ram Pai
2018-01-24 20:54 ` Eric W. Biederman
2018-01-23 21:07 ` [PATCH 07/10] signal/powerpc: Remove unnecessary signal_code parameter of do_send_trap Eric W. Biederman
2018-01-23 21:07 ` Eric W. Biederman [this message]
2018-01-23 21:07 ` [PATCH 09/10] mm/memory_failure: Remove unused trapno from memory_failure Eric W. Biederman
2018-01-23 21:07 ` [PATCH 10/10] signal/memory-failure: Use force_sig_mceerr and send_sig_mceerr Eric W. Biederman
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