ppc currently silently accepts invalid real address access. Catch
these and turn them into machine checks on POWER9/10 machines.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-ID: <20230703120301.45313-1-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
The Power ISA has the concept of sub-processors:
Hardware is allowed to sub-divide a multi-threaded processor into
"sub-processors" that appear to privileged programs as multi-threaded
processors with fewer threads.
POWER9 and POWER10 have two modes, either every thread is a
sub-processor or all threads appear as one multi-threaded processor. In
the user manuals these are known as "LPAR per thread" / "Thread LPAR",
and "LPAR per core" / "1 LPAR", respectively.
The practical difference is: in thread LPAR mode, non-hypervisor SPRs
are not shared between threads and msgsndp can not be used to message
siblings. In 1 LPAR mode, some SPRs are shared and msgsndp is usable.
Thrad LPAR allows multiple partitions to run concurrently on the same
core, and is a requirement for KVM to run on POWER9/10 (which does not
gang-schedule an LPAR on all threads of a core like POWER8 KVM).
Traditionally, SMT in PAPR environments including PowerVM and the
pseries QEMU machine with KVM acceleration behaves as in 1 LPAR mode.
In OPAL systems, Thread LPAR is used. When adding SMT to the powernv
machine, it is therefore preferable to emulate Thread LPAR.
To account for this difference between pseries and powernv, an LPAR mode
flag is added such that SPRs can be implemented as per-LPAR shared, and
that becomes either per-thread or per-core depending on the flag.
Reviewed-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-ID: <20230705120631.27670-2-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
We can get CPUState from env with env_cpu without going through
PowerPCCPU and casting that.
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Message-ID: <28424220f37f51ce97f24cadc7538a9c0d16cb45.1686868895.git.balaton@eik.bme.hu>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Some helpers only have a CPUState local to call cpu_interrupt_exittb()
but we can use env_cpu for that and remove the local.
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Message-ID: <aa34e449552c6ab52d48938ccbe762fc06adac01.1686868895.git.balaton@eik.bme.hu>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
All powerpc exception handlers share some code when handling machine
check exceptions. Move this to a common function.
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Message-ID: <9cfffaa35aa894086dd092af6b0b26f2d62ff3de.1686868895.git.balaton@eik.bme.hu>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
CPUState is rarely needed by this function (only for logging a fatal
error) and it's easy to get from the env parameter so passing it
separately is not necessary.
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Acked-by: Nicholas Piggin <npiggin@gmail.com>
Message-ID: <f42761401c708fd6e02f7523d9f709b1972e5863.1686868895.git.balaton@eik.bme.hu>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Doorbells in SMT need to coordinate msgsnd/msgclr and DPDES access from
multiple threads that affect the same state.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
System call interrupts in ISA v3.1 CPUs add a LEV indication in SRR1
that corresponds with the LEV field of the instruction that caused the
interrupt.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
The hypervisor emulation assistance interrupt modifies HEIR to
contain the value of the instruction which caused the exception.
Only TCG raises HEAI interrupts so this can be made TCG-only.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
ISA v3.1 introduced prefix instructions. Among the changes, various
synchronous interrupts report whether they were caused by a prefix
instruction in (H)SRR1.
The case of instruction fetch that causes an HDSI due to access of a
process-scoped table faulting on the partition scoped translation is the
tricky one. As with ISIs and HISIs, this does not try to set the prefix
bit because there is no instruction image to be loaded. The HDSI needs
the originating access type to be passed through to the handler to
distinguish this from HDSIs that fault translating process scoped tables
originating from a load or store instruction (in that case the prefix
bit should be provided).
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[ clg: checkpatch issues ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
powerpc ifetch endianness depends on MSR[LE] so it has to byteswap
after cpu_ldl_code(). This corrects DSISR bits in alignment
interrupts when running in little endian mode.
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Count exceptions which can be queried with info irq monitor command.
Signed-off-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20230606220200.7EBCC74635C@zero.eik.bme.hu>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
The PMU raises a performance monitor exception (causing an interrupt
when MSR[EE]=1) when MMCR0[PMAO] is set, and lowers it when clear.
Wire this up and implement the interrupt delivery for books. Linux perf
record can now collect PMI-driven samples.
fire_PMC_interrupt is renamed to perfm_alert, which matches a bit closer
to the new terminology used in the ISA and distinguishes the alert
condition (e.g., counter overflow) from the PERFM (or EBB) interrupts.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20230530134313.387252-2-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
BookS msgsndp instruction to self or DPDES register can cause SDOOR
interrupts which crash QEMU with exception not implemented.
Linux does not use msgsndp in SMT1, and KVM only uses DPDES to cause
doorbells when emulating a SMT guest (which is not the default), so
this has gone unnoticed.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20230530130526.372701-1-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
msgclrp matches msgsndp and should clear PPC_INTERRUPT_DOORBELL.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20230530130714.373215-1-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
ppc hypervisors turn HEAI interrupts into program interrupts injected
into the guest that executed the illegal instruction, if the hypervisor
doesn't handle it some other way.
The nested-hv implementation failed to account for this HEAI->program
conversion. The virtual hypervisor wants to see the HEAI when running
a nested guest, so that interrupt type can be returned to its KVM
caller.
Fixes: 7cebc5db2e ("target/ppc: Introduce a vhyp framework for nested HV support")
Cc: balaton@eik.bme.hu
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20230530132127.385001-1-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
This optional behavior was removed from the ISA in v3.0, see
Summary of Changes preface:
Data Storage Interrupt Status Register for Alignment Interrupt:
Simplifies the Alignment interrupt by remov- ing the Data Storage
Interrupt Status Register (DSISR) from the set of registers modified
by the Alignment interrupt.
Reviewed-by: Fabiano Rosas <farosas@suse.de>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-Id: <20230515092655.171206-5-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Adds checks to the hashst and hashchk instructions to only execute if
enabled by the relevant aspect in the DEXCR and HDEXCR.
This behaviour is guarded behind TARGET_PPC64 since Power10 is
currently the only implementation which has the DEXCR.
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Signed-off-by: Nicholas Miehlbradt <nicholas@linux.ibm.com>
Message-Id: <20221220042330.2387944-3-nicholas@linux.ibm.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Kowshik reported that building qemu with GCC 12.2.1 for 'ppc64-softmmu'
target is failing due to following build warnings:
<snip>
../target/ppc/cpu_init.c:7018:13: error: 'ppc_restore_state_to_opc' defined but not used [-Werror=unused-function]
7018 | static void ppc_restore_state_to_opc(CPUState *cs,
<snip>
Fix this by wrapping these function definitions in 'ifdef CONFIG_TCG' so that
they are only defined if qemu is compiled with '--enable-tcg'
Reported-by: Kowshik Jois B S <kowsjois@linux.ibm.com>
Fixes: 61bd1d2942 ("target/ppc: Convert to tcg_ops restore_state_to_opc")
Fixes: 670f1da374 ("target/ppc: Implement hashst and hashchk")
Fixes: 53ae2aeb94 ("target/ppc: Implement hashstp and hashchkp")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1319
Signed-off-by: Vaibhav Jain <vaibhav@linux.ibm.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Kowshik Jois B S <kowsjois@linux.vnet.ibm.com>
Message-Id: <20221116131743.658708-1-vaibhav@linux.ibm.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
The value passed is always true, and if the target's
synchronize_from_tb hook is non-trivial, not exiting
may be erroneous.
Reviewed-by: Claudio Fontana <cfontana@suse.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Move the methods to excp_helper.c and make them static.
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Message-Id: <20221021142156.4134411-4-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
This new method will check if any pending interrupt was unmasked and
then call cpu_interrupt/cpu_reset_interrupt accordingly. Code that
raises/lowers or masks/unmasks interrupts should call this method to
keep CPU_INTERRUPT_HARD coherent with env->pending_interrupts.
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20221021142156.4134411-2-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Export p7_interrupt_powersave and use it in p7_next_unmasked_interrupt.
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20221011204829.1641124-26-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Remove the following unused interrupts from the POWER7 interrupt
processing method:
- PPC_INTERRUPT_RESET: only raised for 6xx, 7xx, 970 and POWER5p;
- Hypervisor Virtualization: introduced in Power ISA v3.0;
- Hypervisor Doorbell and Event-Based Branch: introduced in
Power ISA v2.07;
- Critical Input, Watchdog Timer, and Fixed Interval Timer: only defined
for embedded CPUs;
- Doorbell and Critical Doorbell Interrupt: processor does not implement
the Embedded.Processor Control category;
- Programmable Interval Timer: 40x-only;
- PPC_INTERRUPT_THERM: only raised for 970 and POWER5p;
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20221011204829.1641124-23-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
The new method is identical to ppc_deliver_interrupt, processor-specific
code will be added/removed in the following patches.
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20221011204829.1641124-22-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Remove the following unused interrupts from the POWER7 interrupt masking
method:
- PPC_INTERRUPT_RESET: only raised for 6xx, 7xx, 970 and POWER5p;
- Hypervisor Virtualization: introduced in Power ISA v3.0;
- Hypervisor Doorbell and Event-Based Branch: introduced in
Power ISA v2.07;
- Critical Input, Watchdog Timer, and Fixed Interval Timer: only defined
for embedded CPUs;
- Doorbell and Critical Doorbell Interrupt: processor does not implement
the Embedded.Processor Control category;
- Programmable Interval Timer: 40x-only;
- PPC_INTERRUPT_THERM: only raised for 970 and POWER5p;
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20221011204829.1641124-21-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
The new method is identical to ppc_next_unmasked_interrupt_generic,
processor-specific code will be added/removed in the following patches.
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20221011204829.1641124-20-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Export p8_interrupt_powersave and use it in p8_next_unmasked_interrupt.
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20221011204829.1641124-19-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Remove the following unused interrupts from the POWER8 interrupt
processing method:
- PPC_INTERRUPT_RESET: only raised for 6xx, 7xx, 970 and POWER5p;
- Debug Interrupt: removed in Power ISA v2.07;
- Hypervisor Virtualization: introduced in Power ISA v3.0;
- Critical Input, Watchdog Timer, and Fixed Interval Timer: only defined
for embedded CPUs;
- Critical Doorbell: processor does not implement the
"Embedded.Processor Control" category;
- Programmable Interval Timer: 40x-only;
- PPC_INTERRUPT_THERM: only raised for 970 and POWER5p;
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20221011204829.1641124-16-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
The new method is identical to ppc_deliver_interrupt, processor-specific
code will be added/removed in the following patches.
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20221011204829.1641124-15-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Remove the following unused interrupts from the POWER8 interrupt masking
method:
- PPC_INTERRUPT_RESET: only raised for 6xx, 7xx, 970, and POWER5p;
- Debug Interrupt: removed in Power ISA v2.07;
- Hypervisor Virtualization: introduced in Power ISA v3.0;
- Critical Input, Watchdog Timer, and Fixed Interval Timer: only defined
for embedded CPUs;
- Critical Doorbell: processor does not implement the "Embedded.Processor
Control" category;
- Programmable Interval Timer: 40x-only;
- PPC_INTERRUPT_THERM: only raised for 970 and POWER5p;
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20221011204829.1641124-14-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
The new method is identical to ppc_next_unmasked_interrupt_generic,
processor-specific code will be added/removed in the following patches.
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20221011204829.1641124-13-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Export p9_interrupt_powersave and use it in p9_next_unmasked_interrupt.
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20221011204829.1641124-12-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Remove the following unused interrupts from the POWER9 interrupt
processing method:
- PPC_INTERRUPT_RESET: only raised for 6xx, 7xx, 970 and POWER5p;
- Debug Interrupt: removed in Power ISA v2.07;
- Critical Input, Watchdog Timer, and Fixed Interval Timer: only defined
for embedded CPUs;
- Critical Doorbell Interrupt: removed in Power ISA v3.0;
- Programmable Interval Timer: 40x-only.
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20221011204829.1641124-9-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
The new method is identical to ppc_deliver_interrupt, processor-specific
code will be added/removed in the following patches.
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20221011204829.1641124-8-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Remove the following unused interrupts from the POWER9 interrupt masking
method:
- PPC_INTERRUPT_RESET: only raised for 6xx, 7xx, 970 and POWER5p;
- Debug Interrupt: removed in Power ISA v2.07;
- Critical Input, Watchdog Timer, and Fixed Interval Timer: only defined
for embedded CPUs;
- Critical Doorbell Interrupt: removed in Power ISA v3.0;
- Programmable Interval Timer: 40x-only.
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20221011204829.1641124-7-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
The new method is identical to ppc_next_unmasked_interrupt_generic,
processor-specific code will be added/removed in the following patches.
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Message-Id: <20221011204829.1641124-6-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Use ppc_set_irq to raise/clear interrupts to ensure CPU_INTERRUPT_HARD
will be set/reset accordingly.
Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com>
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Message-Id: <20221011204829.1641124-3-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
This enum defines the bit positions in env->pending_interrupts for each
interrupt. However, except for the comparison in kvmppc_set_interrupt,
the values are always used as (1 << PPC_INTERRUPT_*). Define them
directly like that to save some clutter. No functional change intended.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Message-Id: <20221011204829.1641124-2-matheus.ferst@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
This partially reverts commit 9dc20cc37d ("target/ppc: Simplify
powerpc_excp_booke"), which removed DOORI and DOORCI interrupts.
Without this patch, a -cpu e5500 -smp 2 machine booting Linux
crashes with:
qemu: fatal: Invalid PowerPC exception 36. Aborting
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20220924114436.1422786-1-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Implementation for instructions hashstp and hashchkp, the privileged
versions of hashst and hashchk, which were added in Power ISA 3.1B.
Signed-off-by: Víctor Colombo <victor.colombo@eldorado.org.br>
Reviewed-by: Lucas Mateus Castro <lucas.araujo@eldorado.org.br>
Message-Id: <20220715205439.161110-4-victor.colombo@eldorado.org.br>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Implementation for instructions hashst and hashchk, which were added
in Power ISA 3.1B.
It was decided to implement the hash algorithm from ground up in this
patch exactly as described in Power ISA.
Signed-off-by: Víctor Colombo <victor.colombo@eldorado.org.br>
Reviewed-by: Lucas Mateus Castro <lucas.araujo@eldorado.org.br>
Message-Id: <20220715205439.161110-3-victor.colombo@eldorado.org.br>
[danielhb: fix block comment in excp_helper.c]
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>