kernel.git/arch/powerpc/kernel/traps.c, branch linux-4.19.y

powerpc: Fix build error due to is_valid_bugaddr()

2024-02-23T07:12:43Z

[ Upstream commit f8d3555355653848082c351fa90775214fb8a4fa ] With CONFIG_GENERIC_BUG=n the build fails with: arch/powerpc/kernel/traps.c:1442:5: error: no previous prototype for ‘is_valid_bugaddr’ [-Werror=missing-prototypes] 1442 | int is_valid_bugaddr(unsigned long addr) | ^~~~~~~~~~~~~~~~ The prototype is only defined, and the function is only needed, when CONFIG_GENERIC_BUG=y, so move the implementation under that. Signed-off-by: Michael Ellerman Link: https://msgid.link/20231130114433.3053544-2-mpe@ellerman.id.au Signed-off-by: Sasha Levin

exit: Add and use make_task_dead.

2023-02-06T06:49:45Z

commit 0e25498f8cd43c1b5aa327f373dd094e9a006da7 upstream. There are two big uses of do_exit. The first is it's design use to be the guts of the exit(2) system call. The second use is to terminate a task after something catastrophic has happened like a NULL pointer in kernel code. Add a function make_task_dead that is initialy exactly the same as do_exit to cover the cases where do_exit is called to handle catastrophic failure. In time this can probably be reduced to just a light wrapper around do_task_dead. For now keep it exactly the same so that there will be no behavioral differences introducing this new concept. Replace all of the uses of do_exit that use it for catastraphic task cleanup with make_task_dead to make it clear what the code is doing. As part of this rename rewind_stack_do_exit rewind_stack_and_make_dead. Signed-off-by: "Eric W. Biederman" Signed-off-by: Eric Biggers Signed-off-by: Greg Kroah-Hartman

powerpc: improve handling of unrecoverable system reset

2021-03-17T15:43:46Z

[ Upstream commit 11cb0a25f71818ca7ab4856548ecfd83c169aa4d ] If an unrecoverable system reset hits in process context, the system does not have to panic. Similar to machine check, call nmi_exit() before die(). Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210130130852.2952424-26-npiggin@gmail.com Signed-off-by: Sasha Levin

powerpc: Fix undetected data corruption with P9N DD2.1 VSX CI load emulation

2020-11-05T10:08:51Z

commit 1da4a0272c5469169f78cd76cf175ff984f52f06 upstream. __get_user_atomic_128_aligned() stores to kaddr using stvx which is a VMX store instruction, hence kaddr must be 16 byte aligned otherwise the store won't occur as expected. Unfortunately when we call __get_user_atomic_128_aligned() in p9_hmi_special_emu(), the buffer we pass as kaddr (ie. vbuf) isn't guaranteed to be 16B aligned. This means that the write to vbuf in __get_user_atomic_128_aligned() has the bottom bits of the address truncated. This results in other local variables being overwritten. Also vbuf will not contain the correct data which results in the userspace emulation being wrong and hence undetected user data corruption. In the past we've been mostly lucky as vbuf has ended up aligned but this is fragile and isn't always true. CONFIG_STACKPROTECTOR in particular can change the stack arrangement enough that our luck runs out. This issue only occurs on POWER9 Nimbus <= DD2.1 bare metal. The fix is to align vbuf to a 16 byte boundary. Fixes: 5080332c2c89 ("powerpc/64s: Add workaround for P9 vector CI load issue") Cc: stable@vger.kernel.org # v4.15+ Signed-off-by: Michael Neuling Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201013043741.743413-1-mikey@neuling.org Signed-off-by: Greg Kroah-Hartman

powerpc/traps: Make unrecoverable NMIs die instead of panic

2020-10-01T11:14:44Z

[ Upstream commit 265d6e588d87194c2fe2d6c240247f0264e0c19b ] System Reset and Machine Check interrupts that are not recoverable due to being nested or interrupting when RI=0 currently panic. This is not necessary, and can often just kill the current context and recover. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Reviewed-by: Christophe Leroy Link: https://lore.kernel.org/r/20200508043408.886394-16-npiggin@gmail.com Signed-off-by: Sasha Levin

powerpc: dump kernel log before carrying out fadump or kdump

2019-10-07T16:57:02Z

[ Upstream commit e7ca44ed3ba77fc26cf32650bb71584896662474 ] Since commit 4388c9b3a6ee ("powerpc: Do not send system reset request through the oops path"), pstore dmesg file is not updated when dump is triggered from HMC. This commit modified system reset (sreset) handler to invoke fadump or kdump (if configured), without pushing dmesg to pstore. This leaves pstore to have old dmesg data which won't be much of a help if kdump fails to capture the dump. This patch fixes that by calling kmsg_dump() before heading to fadump ot kdump. Fixes: 4388c9b3a6ee ("powerpc: Do not send system reset request through the oops path") Reviewed-by: Mahesh Salgaonkar Reviewed-by: Nicholas Piggin Signed-off-by: Ganesh Goudar Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190904075949.15607-1-ganeshgr@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/traps: Fix the message printed when stack overflows

2019-03-23T19:10:08Z

commit 9bf3d3c4e4fd82c7174f4856df372ab2a71005b9 upstream. Today's message is useless: [ 42.253267] Kernel stack overflow in process (ptrval), r1=c65500b0 This patch fixes it: [ 66.905235] Kernel stack overflow in process sh[356], r1=c65560b0 Fixes: ad67b74d2469 ("printk: hash addresses printed with %p") Cc: stable@vger.kernel.org # v4.15+ Signed-off-by: Christophe Leroy [mpe: Use task_pid_nr()] Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/traps: fix recoverability of machine check handling on book3s/32

2019-03-23T19:10:08Z

commit 0bbea75c476b77fa7d7811d6be911cc7583e640f upstream. Looks like book3s/32 doesn't set RI on machine check, so checking RI before calling die() will always be fatal allthought this is not an issue in most cases. Fixes: b96672dd840f ("powerpc: Machine check interrupt is a non-maskable interrupt") Fixes: daf00ae71dad ("powerpc/traps: restore recoverability of machine_check interrupts") Signed-off-by: Christophe Leroy Cc: stable@vger.kernel.org Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/traps: restore recoverability of machine_check interrupts

2018-11-21T08:19:08Z

[ Upstream commit daf00ae71dad8aa05965713c62558aeebf2df48e ] commit b96672dd840f ("powerpc: Machine check interrupt is a non- maskable interrupt") added a call to nmi_enter() at the beginning of machine check restart exception handler. Due to that, in_interrupt() always returns true regardless of the state before entering the exception, and die() panics even when the system was not already in interrupt. This patch calls nmi_exit() before calling die() in order to restore the interrupt state we had before calling nmi_enter() Fixes: b96672dd840f ("powerpc: Machine check interrupt is a non-maskable interrupt") Signed-off-by: Christophe Leroy Reviewed-by: Nicholas Piggin Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

powerpc/traps: Avoid rate limit messages from show unhandled signals

2018-08-20T10:19:46Z

In the recent commit to add an explicit ratelimit state when showing unhandled signals, commit 35a52a10c3ac ("powerpc/traps: Use an explicit ratelimit state for show_signal_msg()"), I put the check of show_unhandled_signals and the ratelimit state before the call to unhandled_signal() so as to avoid unnecessarily calling the latter when show_unhandled_signals is false. However that causes us to check the ratelimit state on every call, so if we take a lot of *handled* signals that has the effect of making the ratelimit code print warnings that callbacks have been suppressed when they haven't. So rearrange the code so that we check show_unhandled_signals first, then call unhandled_signal() and finally check the ratelimit state. Signed-off-by: Michael Ellerman Reviewed-by: Murilo Opsfelder Araujo