[PATCH v2 0/2] signal(7) fixes

[PATCH v2 0/2] signal(7) fixes

[Dev Jain]

This is a follow-up to the following, or any subsequent versions of it:
https://lore.kernel.org/all/20240611075650.814397-1-dev.jain@arm.com/

This patchset brings distinction between the set of blocked signals stored
in uc_sigmask, and the actual set of blocked signals. Also, fix a wrong
mention of sigprocmask(), and replace it with sigaction().

Changes in v2:
- Make the description clear and concise
- Use semantic newlines

Dev Jain (2):
  signal.7: Clearly describe ucontext kernel dump to userspace
  signal.7: Fix wrong mention of sigprocmask

 man/man7/signal.7 | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

-- 
2.34.1

[PATCH v2 1/2] signal.7: Clearly describe ucontext kernel dump to userspace

[Dev Jain]

The set of blocked signals is updated from struct sigaction after the
kernel dumps ucontext. Mention this to avoid misunderstanding.

Signed-off-by: Dev Jain <dev.jain@arm.com>
---
 man/man7/signal.7 | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/man/man7/signal.7 b/man/man7/signal.7
index 4ba5306c8..7d22a7cfe 100644
--- a/man/man7/signal.7
+++ b/man/man7/signal.7
@@ -282,7 +282,13 @@ the thread's alternate signal stack settings.
 .B SA_SIGINFO
 flag, then the above information is accessible via the
 .I ucontext_t
-object that is pointed to by the third argument of the signal handler.)
+object that is pointed to by the third argument of the signal handler.
+This object reflects the state at which the signal is delivered, rather
+than in the handler;
+for example, the mask of blocked signals stored in this object will not
+contain the mask of new signals blocked through
+.BR sigaction(2)).
+
 .IP (1.4)
 Any signals specified in
 .I act\->sa_mask
-- 
2.34.1

Re: [PATCH v2 1/2] signal.7: Clearly describe ucontext kernel dump to userspace

[Alejandro Colomar]

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On Tue, Jun 11, 2024 at 02:38:22PM GMT, Dev Jain wrote:
> The set of blocked signals is updated from struct sigaction after the
> kernel dumps ucontext. Mention this to avoid misunderstanding.
> 
> Signed-off-by: Dev Jain <dev.jain@arm.com>

Hi Dev,

I've applied this patch, with some minor tweaks:
<https://www.alejandro-colomar.es/src/alx/linux/man-pages/man-pages.git/commit/?h=contrib&id=9e1f221b2099ee2c936ce4d6562a61e1e253af47>

Have a lovely day!
Alex

> ---
>  man/man7/signal.7 | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/man/man7/signal.7 b/man/man7/signal.7
> index 4ba5306c8..7d22a7cfe 100644
> --- a/man/man7/signal.7
> +++ b/man/man7/signal.7
> @@ -282,7 +282,13 @@ the thread's alternate signal stack settings.
>  .B SA_SIGINFO
>  flag, then the above information is accessible via the
>  .I ucontext_t
> -object that is pointed to by the third argument of the signal handler.)
> +object that is pointed to by the third argument of the signal handler.
> +This object reflects the state at which the signal is delivered, rather
> +than in the handler;
> +for example, the mask of blocked signals stored in this object will not
> +contain the mask of new signals blocked through
> +.BR sigaction(2)).
> +
>  .IP (1.4)
>  Any signals specified in
>  .I act\->sa_mask
> -- 
> 2.34.1
> 
> 

-- 
<https://www.alejandro-colomar.es/>

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Re: [PATCH v2 1/2] signal.7: Clearly describe ucontext kernel dump to userspace

[Alejandro Colomar]

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On Mon, Jun 17, 2024 at 12:54:10PM GMT, Alejandro Colomar wrote:
> On Tue, Jun 11, 2024 at 02:38:22PM GMT, Dev Jain wrote:
> > The set of blocked signals is updated from struct sigaction after the
> > kernel dumps ucontext. Mention this to avoid misunderstanding.
> > 
> > Signed-off-by: Dev Jain <dev.jain@arm.com>
> 
> Hi Dev,
> 
> I've applied this patch, with some minor tweaks:
> <https://www.alejandro-colomar.es/src/alx/linux/man-pages/man-pages.git/commit/?h=contrib&id=9e1f221b2099ee2c936ce4d6562a61e1e253af47>

Whoops; I found another issue, and amended:
<https://www.alejandro-colomar.es/src/alx/linux/man-pages/man-pages.git/commit/?h=contrib&id=b8136d84eb3b9b1db0dd6f54f47c1c104682f44f>


> 
> Have a lovely day!
> Alex
> 
> > ---
> >  man/man7/signal.7 | 8 +++++++-
> >  1 file changed, 7 insertions(+), 1 deletion(-)
> > 
> > diff --git a/man/man7/signal.7 b/man/man7/signal.7
> > index 4ba5306c8..7d22a7cfe 100644
> > --- a/man/man7/signal.7
> > +++ b/man/man7/signal.7
> > @@ -282,7 +282,13 @@ the thread's alternate signal stack settings.
> >  .B SA_SIGINFO
> >  flag, then the above information is accessible via the
> >  .I ucontext_t
> > -object that is pointed to by the third argument of the signal handler.)
> > +object that is pointed to by the third argument of the signal handler.
> > +This object reflects the state at which the signal is delivered, rather
> > +than in the handler;
> > +for example, the mask of blocked signals stored in this object will not
> > +contain the mask of new signals blocked through
> > +.BR sigaction(2)).
> > +
> >  .IP (1.4)
> >  Any signals specified in
> >  .I act\->sa_mask
> > -- 
> > 2.34.1
> > 
> > 
> 
> -- 
> <https://www.alejandro-colomar.es/>



-- 
<https://www.alejandro-colomar.es/>

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[PATCH v2 2/2] signal.7: Fix wrong mention of sigprocmask

[Dev Jain]

The handler is registered with sigaction(), not sigprocmask(). Even if the
purpose of writing sigprocmask() here was to mention blocked signals, the
statement currently concerns the "addition" of blocked signals; signals
blocked through sigprocmask() would already be present in the thread
context of blocked signals.

Fixes: e7a5700 (getcontext.3, signal.7: tfix)
Signed-off-by: Dev Jain <dev.jain@arm.com>
---
 man/man7/signal.7 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/man/man7/signal.7 b/man/man7/signal.7
index 7d22a7cfe..57eab7847 100644
--- a/man/man7/signal.7
+++ b/man/man7/signal.7
@@ -293,7 +293,7 @@ contain the mask of new signals blocked through
 Any signals specified in
 .I act\->sa_mask
 when registering the handler with
-.BR sigprocmask (2)
+.BR sigaction (2)
 are added to the thread's signal mask.
 The signal being delivered is also
 added to the signal mask, unless
-- 
2.34.1

Re: [PATCH v2 2/2] signal.7: Fix wrong mention of sigprocmask

[Mark Brown]

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On Tue, Jun 11, 2024 at 02:38:23PM +0530, Dev Jain wrote:
> The handler is registered with sigaction(), not sigprocmask(). Even if the
> purpose of writing sigprocmask() here was to mention blocked signals, the
> statement currently concerns the "addition" of blocked signals; signals
> blocked through sigprocmask() would already be present in the thread
> context of blocked signals.

Reviewed-by: Mark Brown <broonie@kernel.org>

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Re: [PATCH v2 2/2] signal.7: Fix wrong mention of sigprocmask

[Alejandro Colomar]

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Hi Dev, Mark,

On Tue, Jun 11, 2024 at 02:06:31PM GMT, Mark Brown wrote:
> On Tue, Jun 11, 2024 at 02:38:23PM +0530, Dev Jain wrote:
> > The handler is registered with sigaction(), not sigprocmask(). Even if the
> > purpose of writing sigprocmask() here was to mention blocked signals, the
> > statement currently concerns the "addition" of blocked signals; signals
> > blocked through sigprocmask() would already be present in the thread
> > context of blocked signals.
> 
> Reviewed-by: Mark Brown <broonie@kernel.org>

Thanks for the patch and the review!  I've applied the patch.  It will
be included in the man-pages-6.9.1 release later today.

Have a lovely day!
Alex

-- 
<https://www.alejandro-colomar.es/>

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