Le 08/04/2020 à 08:40, Brice Goglin a écrit : > Le 31/03/2020 à 00:29, Brice Goglin a écrit : >> Le 31/03/2020 à 00:05, Philippe Mathieu-Daudé a écrit : >>> On 3/30/20 9:07 PM, Brice Goglin wrote: >>>> When the program name is very long, qemu-user may truncate it in >>>> /proc/self/stat. However the truncation must keep the ending ") " >>>> to conform to the proc manpage which says: >>>> (2) comm %s >>>> The filename of the executable, in parentheses. This >>>> is visible whether or not the executable is swapped >>>> out. >>>> >>>> To reproduce: >>>> $ ln -s /bin/cat <filenamewithmorethan128chars> >>>> $ qemu-x86_64 ./<filenamewithmorethan128chars> /proc/self/stat >>>> >>>> Before the patch, you get: >>>> 1134631 (<filenametruncated>0 0 0 0 0 0 0 0 ... >>>> After the patch: >>>> 1134631 (<filenametruncat>) 0 0 0 0 0 0 0 0 ... >>>> >>>> This fixes an issue with hwloc failing to parse /proc/self/stat >>>> when Ludovic Courtes was testing it in guix over qemu-aarch64. >>>> >>>> Signed-off-by: Brice Goglin<brice.gog...@inria.fr> >>>> >>>> diff --git a/linux-user/syscall.c b/linux-user/syscall.c >>>> index 5af55fca78..a1126dcf5b 100644 >>>> --- a/linux-user/syscall.c >>>> +++ b/linux-user/syscall.c >>>> @@ -7305,7 +7305,10 @@ static int open_self_stat(void *cpu_env, int fd) >>>> snprintf(buf, sizeof(buf), "%"PRId64 " ", val); >>>> } else if (i == 1) { >>>> /* app name */ >>>> - snprintf(buf, sizeof(buf), "(%s) ", ts->bprm->argv[0]); >>>> + len = snprintf(buf, sizeof(buf), "(%s) ", ts->bprm->argv[0]); >>>> + if (len >= sizeof(buf)) >>>> + /* bring back the ending ") " that was truncated */ >>>> + strcpy(buf+sizeof(buf)-3, ") "); >>> Maybe we can avoid the sprintf() call: >>> >>> -- >8 -- >>> diff --git a/linux-user/syscall.c b/linux-user/syscall.c >>> --- a/linux-user/syscall.c >>> +++ b/linux-user/syscall.c >>> @@ -7305,7 +7305,11 @@ static int open_self_stat(void *cpu_env, int fd) >>> snprintf(buf, sizeof(buf), "%"PRId64 " ", val); >>> } else if (i == 1) { >>> /* app name */ >>> - snprintf(buf, sizeof(buf), "(%s) ", ts->bprm->argv[0]); >>> + char *ptr = buf; >>> + >>> + *ptr++ = '('; >>> + ptr = stpncpy(ptr, ts->bprm->argv[0], sizeof(buf) - 3); >>> + strcpy(ptr, ") "); >>> } else if (i == 27) { >>> /* stack bottom */ >>> val = start_stack; >>> >> This works too. > > > Hello > > Is anybody going to fix this anyhow for the next release?
Hi, we are expecting you fix the patch according to Philippe's comment and re-send it or explain why you don't want. Thanks, Laurent